What are u working on right now (electronics related and with picture please)? - Page 1
Forum section: electronics / general

author: DutchGert
author_rank: Frequent Contributor
timestamp: September 27, 2013, 08:18:37 am
content: To start: Currently I am doing 1000BASE-T pre-compliance tests on a HMI product. Not very daring but I can play around with a nice $35000 scope and MS-DOS to run the crappy test patern generation software from.What are u guys doing?And please remember:

author: andtfoot
author_rank: Unknown
timestamp: September 27, 2013, 08:55:49 am
content: I've got a few things on the run in various states. The one on my bench at home right now though is an 'Octopus tester' with selectable voltage (multi-tap tranny) and adjustable current (10k pot).Other stuff I'm working on:-EDID minder/monitor emulator for VGA-Learning how to write to eeprom via I2C with 8051 chip.-Unbricking a Crestron control system (learning 0.5mm pitch TSOP soldering in the process)

author: BravoV
author_rank: Super Contributor
timestamp: September 27, 2013, 09:26:34 am
content: Quote from: DutchGert on September 27, 2013, 08:18:37 amThe pcb layout looks like an absoluut n00b job.

author: DutchGert
author_rank: Frequent Contributor
timestamp: September 27, 2013, 09:32:16 am
content: Quote from: BravoV on September 27, 2013, 09:26:34 amLol, thats the Tektronix test jig u have to use in order to do the automated (pre)compliance test.The D.U.T looks a lot nicer I can tell

author: FrankBuss
author_rank: Unknown
timestamp: September 27, 2013, 11:23:26 am
content: I'm working on myCrazy Cartridge. I tried to access the sd card, but the LPC11U24 microcontroller has to little flash for the FAT filesystem implementation of thembed-framework, just 32kB. Easy, just replace it with a pin compatible LPC11U37 with 128kB flash and patching some linker definition files. But when trying to desolder it with a hot air gun, I broke most traces (have to practice more with old ISA cards). So I dead-bug style glued the microcontroller on top of the FPGA. I had to glue a SD card socket, too, because I couldn't solder wires to the micro-SD card socket on the board (next time I'll add more test points or at least vias). First it didn't work. I attached a logic analyzer:It was just a missing pin direction, now this interesting looking construction is actually working and I can read/write files as easy as in C with fopen/fread/fwrite/fprintf.

author: SLJ
author_rank: Frequent Contributor
timestamp: September 27, 2013, 12:09:09 pm
content: Restoration of this vintage Simpson signal generator I picked up last week.Could not pas it by as I love the front panel design. It will be a nice addition to my collection.

author: ElectroIrradiator
author_rank: Frequent Contributor
timestamp: September 27, 2013, 01:34:09 pm
content: The items shown here are related to the same project, that being the work I'm doing on getting my home lab back into proper condition. For a number of reasons I haven't done too much to keep my home lab in tip top shape for a number of years, something I am now slowly trying to correct.One of the priorities is getting all the cruft jettisoned, to make more room for a more modern and appropriate work space. To this end a couple I know fell in love with an old Grundig 1097 tube radio from the late fifties, which I have had kicking about. There is a sizable Bakelite cabinet to go with the chassis seen here, and they have promised to give it a good home. If, that is, I can get it back into a technical condition, where I didn't feel I'd embarrass myself by giving it to them. The FM receiver is fairly primitive, and I'll probably have my work cut out making it reasonably well behaved, given today's crowded FM band. Will probably have to poke it with ye olde 3325B at some point, among other measures. This will be a component level restoration. Fun, fun, fun.The embarrassing truth behind the Weller is that it doesn't actually belong to me, and now the owner has kindly asked to get it back.So today its replacement arrived, as seen here. This is also part of getting the lab back into shape.

author: GeoffS
author_rank: Unknown
timestamp: September 27, 2013, 02:05:09 pm
content: Not a lot of electronic content but lots of wiresA new controller panel for my CNC router. It will be mostly DIN rail connectors with the green components used to mount not DIN components to the rails.50V for the most part but 240V AC for the VFD shown at top right. This drives the spindle motor which is 380V 400Hz

author: Alana
author_rank: Frequent Contributor
timestamp: September 27, 2013, 02:27:43 pm
content: Prototype of electronic clock for model railway exhibition - I'm in the middle of laying out board for this schematic and those displays.

author: Bertho
author_rank: Regular Contributor
timestamp: September 27, 2013, 02:34:59 pm
content: The Executive Decision Maker ProThe Executive Decision Maker Pro is your tool to support your everyday decision making from trivial household decisions to multi-billion dollar Mega-Corp venture decisions and every management level in between (see note 1). The Executive Decision Maker Pro embeds an Intentional Synchronizer which, with the right expressed brainwave patterns, reads your mind at the subconscious level and automatically chooses the correct answer (see note 2).[edit: finished the project, seehttp://www.vagrearg.org/content/edm-profor details]1. Decisions and their consequences are the responsibility of those who execute them.2. Some superstitious believes and retro-reasoning may be required for optimal effectiveness.

author: blackdog
author_rank: Frequent Contributor
timestamp: September 27, 2013, 03:31:35 pm
content: Hi!I'm building a LAb Voltage Reference.First the preliminary circuit...The oven is working as it should, next week I start with the voltage reference.First picture of the Powerresistor BPR10Here i glue a thin piece of FR4 PCB material on the power resistor with special thermal adhesive.Checking :-)Power FET and current limiting resistor.The 2N3906 and the LM10 is mountedThe circuit is now ready.In the center below the thermal glue is the 100K NTC resistor.These are the components for the reference side.The temp for the oven is about 45CVoltage = 12VI= 52mA no reference mounted and simple isolation and 22C LAB temp.Doc reference IC VRE310.http://www.bramcam.nl/NA/BPR10-Oven/VRE310.pdfDoc LTC2057 opamp.http://www.bramcam.nl/NA/BPR10-Oven/LTC2057.pdfMaybe next week more, if i have time...Kind regarts,Blackdog

author: ElectroIrradiator
author_rank: Frequent Contributor
timestamp: September 27, 2013, 05:44:40 pm
content: Quote from: blackdog on September 27, 2013, 03:31:35 pmLooks like a nice project! However, didn't you mean to use a 2N3904(NPN BJT) for the current limiter? The 2N3906is a PNP BJT, which won't work at the position indicated on the schematic.

author: blackdog
author_rank: Frequent Contributor
timestamp: September 27, 2013, 05:52:21 pm
content: Hi ElectroIrradiator,YES!, my bad ;-)Thanks, edit the schematic.Kind regarts,Blackdog

author: TMM
author_rank: Frequent Contributor
timestamp: September 27, 2013, 05:56:09 pm
content: Just starting a board which will be part of an audio amplifier 'dyno' - basically a configurable (1-16ohm) high power resistive load and a THD analyser. Took me a little while to work out that the ISCP on the ATMega128 uses UART0 pins instead of MOSI/MISO, doh! Good thing those pins were already broken out.Go easy on the hand soldered autorouted toner transfer PCB

author: tarrryan
author_rank: Newbie
timestamp: September 27, 2013, 07:22:46 pm
content: Trying to decide how to layout my robotics controls for transport.

author: yrrapt
author_rank: Contributor
timestamp: September 27, 2013, 08:09:59 pm
content: Working on second revision of PCBs for a university project which ejects two cubesats from a sounding rocket at an altitude of ~80km to test novel inflatable structures. There was a failure to eject the cubesats on the first launch so we're gearing up for a relaunch early next year and get the opportunity to fix all those "if I was starting again I would have done this differently" bugs.A picture of the cubesats sitting on the module which ejects them and I've thrown in a video of the launch for good measure (I can't figure how to embed it unfortunately).https://www.facebook.com/photo.php?v=588795681144574Tom

author: DutchGert
author_rank: Frequent Contributor
timestamp: September 27, 2013, 08:38:55 pm
content: Quote from: yrrapt on September 27, 2013, 08:09:59 pmWorking for Clyde Space and/or Surrey by any chance? I admire the PSU u guys made for CubeSat's. I did some work for ESL in Stellenbosch last year myself. CubeSat's rock!

author: DutchGert
author_rank: Frequent Contributor
timestamp: September 27, 2013, 08:40:25 pm
content: Quote from: marshallh on September 27, 2013, 06:40:41 pmLooks slick, what does it do?

author: yrrapt
author_rank: Contributor
timestamp: September 27, 2013, 08:45:07 pm
content: Quote from: DutchGert on September 27, 2013, 08:38:55 pmNope, just a lowly student at the moment. Clyde space are very well known around here and doing some really cool stuff, the whole cubesat scene is very exciting at the moment even if does still cost $$$$$$$ to get on a launcher.Tom

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: September 27, 2013, 08:57:23 pm
content: 7 MHz phasing SSB transceiverBecause it uses the phasing method no filters or frequency conversions are required between audio and the 7 MHz transmit frequency. The circuitry is also bidirectional with passive stages, cutting down on intermediate stages.A video describing the process is below.

author: Smokey
author_rank: Super Contributor
timestamp: September 27, 2013, 09:37:29 pm
content: Quote from: DutchGert on September 27, 2013, 08:40:25 pmHow do you keep those resistors and caps connected with little wires off to the sides of the board from getting all bent and shorting together ? ? ? ? ?

author: senso
author_rank: Frequent Contributor
timestamp: September 27, 2013, 09:47:25 pm
content: It gets USB 3.0 and some sort of PCI interface, so, why, could be a lot of things(hardware usb 3.0 analyzer?)

author: opablo
author_rank: Regular Contributor
timestamp: September 27, 2013, 11:24:49 pm
content: A wall-clock that tells the time like a letters soup. Words are in spanish... Birthday present for my sister.I'm just a hobbist... I know this is not hardcore like some other projects...(yes; I know it's missing current limiting resistors to reduce the stress on that atmel... I Added 20x10Ks after the photo was taken)

author: mtdoc
author_rank: Super Contributor
timestamp: September 27, 2013, 11:35:13 pm
content: Quote from: opablo on September 27, 2013, 11:24:49 pmQue Bueno!

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 28, 2013, 12:36:26 am
content: Hybrid air conditioner that also makes hot water:Power input circuits:Note the EMI filter (so the PLC receiver will operate better), surge protector (pink module), and homemade hard start kit. The hard start kit isn't really necessary with a rotary compressor (especially after giving it the "Davuluri Treatment" with ES22a - less pressure to start against), but when it's so cheap, why not?The water pump and evaporator fans are inverter drive since they must be variable speed to allow the control I have in mind, but inverter driving the compressor would have little benefit in my particular application, so I'm leaving that out for now. The real magic is going to be the electronics that control it all. I plan to have an OpenWRT-based web UI that shows the operation of the system.

author: Rick Law
author_rank: Super Contributor
timestamp: September 28, 2013, 02:12:21 am
content: What am I working on now and picture?She is an "oh wow" and her name is.... Wait... What the h*ll makes you think I will tell you her name? And a picture of her? What do you think my wife would do to me, huh?(Now, putting fantasies aside...)-----------------------I am working on what I call a "DinoMeter". An AT Mega based volt logger and I am working on it as a learning process. I call it Dino-Meter because I want to use one of my dinosaur laptops as the logger. Beside, all this arduinos, fundinos, whatever-nos, DinoMeter just fit.I am almost done and I will post something when done.

author: orion242
author_rank: Unknown
timestamp: September 28, 2013, 02:41:17 am
content: Quote from: NiHaoMike on September 28, 2013, 12:36:26 amComing from the deep end of the HVAC field myself, I feel a bit cheated without a pic of the water HX.What are you building this from? PTAC & water source HP, window shaker?What are you planning on using the HW for? Domestic preheat of the hot water heater?Guess I will have to take some shots of my current electronics / hvac related crap'o'la I'm working on.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 28, 2013, 03:46:48 am
content: Quote from: orion242 on September 28, 2013, 02:41:17 amThe water cooled condenser is an off the shelf "snake" heat exchanger, buried underneath the foam insulation. Outside of the insulation, it looks like this, except mine has all 4 connections going the same way.http://surpluscityliquidators.com/view_product/168655////170_TON_COAX_COILIt's a window A/C mounted on top of an old 2U server case. The original condenser was reused as a second evaporator, with an ejector tube providing two stages for better dehumidification. The rather inefficient PSC fan (which was responsible for at least 10% of the power usage in its original configuration!) was replaced with a pair of Delta fans with Cindy Wu sensorless drive, similar to (but not quite as powerful as) the one in my desktop PC. They also have the advantage of being able to slow down to further enhance dehumidification, but still be able to run flat out for high EER when dehumidification is not needed. Even when running at full power, the two fans use only 16W and push more air than the original fan.The hot water is indeed for domestic use. Think of the unit as similar to the Airtap, but with more sophisticated controls and designed so that it attaches to the water pipes under the sink. Because of the "Davuluri Treatment" (using ES22a in a R410a compressor), it has no difficulty getting the water all the way up to 140F (with room to go even higher) for effective dishwashing. Under more usual conditions, I plan on 110F (or so) hot water for better efficiency, but is still plenty hot enough for showering.BTW, the "Davuluri Treatment" got its name from a model who recently lost a lot of weight.http://www.ibtimes.com/nina-davuluri-was-plus-size-winning-miss-america-calling-mallory-hagan-fat-f-k-photos-1407590If you take her "before" and "after" weights and put them on the area of a penny, the resulting pressures are roughly equivalent to R410a and R290 (which is what ES22a is mostly made of) at 115F condensing temperature. I can tell you that the compressor seems to run much quieter and "happier" afterwards. (Not too surprising when Nina was very happy about losing that much weight. For that matter, I would be very happy losing that weight, too!)

author: ElectroIrradiator
author_rank: Frequent Contributor
timestamp: September 28, 2013, 03:51:31 am
content: Quote from: Rick Law on September 28, 2013, 02:12:21 amYou forgot to attach the photos.

author: c4757p
author_rank: Super Contributor
timestamp: September 28, 2013, 04:02:34 pm
content: An instructional function generator kit (0.1Hz - 5MHz, sine square and tri, AM, FM, sweep, digital frequency/amplitude readout) with an accompanying instruction "manual" providing in-depth lessons and explanations of the circuit operation, from resistors to long-tailed pairs and Gilbert cells, targeted at beginning analog electronics enthusiasts.Here's a Jim-style prototype of the comparator which forms the main oscillator. It's very much inspired by the discrete comparator used in the HP 3312A (mostly, it's just been simplified a slight bit). Works a treat up to 16 MHz! And the ringing is just from my atrocious probing setup - I forgot about W2AEW's awesome probe socket trick until afterwards(Also, I have a handful of other projects languishing on the vast back burner)

author: FrankBuss
author_rank: Unknown
timestamp: September 28, 2013, 04:24:26 pm
content: Quote from: c4757p on September 28, 2013, 04:02:34 pmSounds interesting, do you plan to publish it on a webpage? I've done a similar signal generator, but with a different feature set, e.g. no sweep or modulation, but with additional noise output and a serial port to configure it from a PC program:http://www.frank-buss.de/SignalGenerator/index.html

author: c4757p
author_rank: Super Contributor
timestamp: September 28, 2013, 04:37:16 pm
content: Yep, I do. My plan is to put the book PDF, all the Gerbers and schematics and BOMs online, and then at least try to sell a little kit version: PCBs, a print copy of the manual, and a pair of SMD tweezers and a flux pen. The only equipment required to test and adjust it is a 20 MHz scope and a cheapo DMM (not even a bench PSU), so it's quite possible for a true beginner with a very sparse workbench to use it both for learning the circuitry and getting a perfectly good function generator

author: FrankBuss
author_rank: Unknown
timestamp: September 28, 2013, 05:00:57 pm
content: Nice. Please post a link to this thread when you are done, so that I get notified (or a link to your blog or the like), because I don't know much about analog electronics (which your generator mostly looks like) and I could learn something from it.

author: c4757p
author_rank: Super Contributor
timestamp: September 28, 2013, 05:05:14 pm
content: I'm going to start a thread later today to hold everything I have related to that. I'm still pretty early in the actual "done asking stupid questions, now let's build shit" phase, so I'll update it pretty regularly for a while.

author: Stonent
author_rank: Super Contributor
timestamp: September 28, 2013, 06:17:16 pm
content: Guess

author: jancumps
author_rank: Unknown
timestamp: September 28, 2013, 07:33:47 pm
content: More mechanic then elektronic:I'm tuning my DUAL TT collection to original specs

author: JeanF
author_rank: Regular Contributor
timestamp: September 28, 2013, 07:39:32 pm
content: Quote from: Stonent on September 28, 2013, 06:17:16 pmGeiger counter ?

author: krenzo
author_rank: Regular Contributor
timestamp: September 28, 2013, 08:57:22 pm
content: UWB RF Position Tracking System for Virtual Reality applications:I demoed it at Valve Software months ago to a positive response.

author: tehmeme
author_rank: Regular Contributor
timestamp: September 28, 2013, 09:48:53 pm
content: Quote from: c4757p on September 28, 2013, 05:05:14 pmlooking forward to it here too..

author: FrankBuss
author_rank: Unknown
timestamp: September 28, 2013, 10:36:23 pm
content: Quote from: krenzo on September 28, 2013, 08:57:22 pmInteresting. Does it work too, when you do multiple full fast and slow 360° rotations around any axis? Does it work if triangulation is not possible because the senders and the receiver are all in one plane?QuoteI thought they canceled their VR/AR developments because they let most of their hardware team go?

author: krenzo
author_rank: Regular Contributor
timestamp: September 28, 2013, 11:30:33 pm
content: Quote from: FrankBuss on September 28, 2013, 10:36:23 pmIt should still work regardless of rotation. It would fail in that case, but my system is setup to not encounter that situation.QuoteNo, that's not the case. They only fired a few members who have gone on to start the CastAR project that is kickstarting soon. Valve just announced their new controller that I got to demo while I was there that the hardware team was working on.

author: GK
author_rank: Super Contributor
timestamp: September 29, 2013, 01:02:51 am
content: Finishing my audio THD analyser.

author: c4757p
author_rank: Super Contributor
timestamp: September 29, 2013, 01:09:38 am
content: Holy shit, that looks really good.Question: do you have some sort of clear coating over the copper on those PCBs? Around here, they wouldn't stay that shiny for even a day exposed. Or is it just dry where you live?

author: FrankBuss
author_rank: Unknown
timestamp: September 29, 2013, 01:16:13 am
content: Quote from: GK on September 29, 2013, 01:02:51 amThis looks very professional, like a System Two. What is the lowest THDdByou can measure with it?

author: xrunner
author_rank: Super Contributor
timestamp: September 29, 2013, 01:33:36 am
content: Awesome work. You know, the mechanical work is not easy to do either, that's takes a lot of skill.

author: GK
author_rank: Super Contributor
timestamp: September 29, 2013, 07:13:57 am
content: Quote from: FrankBuss on September 29, 2013, 01:16:13 amThe analysers THD+N floor currently hovers at around 1 to 2 parts per million or less (depends on test frequency), depending on how well I can shield the cabling and DUT from the troublesome RFI from the local broadcast AM transmitter.Most details here:http://www.users.on.net/~glenk/thd/thd.htm

author: GK
author_rank: Super Contributor
timestamp: September 29, 2013, 07:15:17 am
content: Quote from: c4757p on September 29, 2013, 01:09:38 amThe boards have a clear conformable coat. They are already over a year old. I have >10 year old boards done the same that look just as new.

author: Stonent
author_rank: Super Contributor
timestamp: September 29, 2013, 08:36:23 am
content: Quote from: JeanF on September 28, 2013, 07:39:32 pm

author: andtfoot
author_rank: Unknown
timestamp: September 29, 2013, 05:57:07 pm
content: Quote from: andtfoot on September 27, 2013, 08:55:49 amAllllllmost...Great guns!

author: tszaboo
author_rank: Super Contributor
timestamp: September 29, 2013, 06:40:15 pm
content: My running projects:http://nandblog.com/running-projects/Some of them even have pictures uploaded in the menu.

author: Skimask
author_rank: Super Contributor
timestamp: September 30, 2013, 03:55:00 am
content: D.A.V.E. - Dave the Autonomous Vehicle ExperimentNeighbor was going to throw this truck in the garbage a few days ago. Kids outgrew it, battery was shot, switches are shot, but the motors, gears, steering, etc. are all still ok.I snagged it. A friend and I are going to rework it, add a handful of sensors, GPS, ultrasonic, IR, LASER range finders (if I can find something in a reasonable $$$ range), cameras, WIFI, bluetooth, XBee, R/C, whatever else we can think of to throw at it, as long as it's not too crazy expensive (e.g. GPS-RTK is likely more than I want to spend on it). And I'm taking ideas!Just getting started on it. Haven't even figured out which MOSFETs I want to use in the H-bridge...

author: smashedProton
author_rank: Frequent Contributor
timestamp: September 30, 2013, 04:07:19 am
content: Quote from: c4757p on September 28, 2013, 04:02:34 pmSend me your final manual and stuff and I will review it for you. I'm a beginning analog enthusiast

author: c4757p
author_rank: Super Contributor
timestamp: September 30, 2013, 04:11:28 am
content: I'm posting as I go, overhere.

author: KJDS
author_rank: Super Contributor
timestamp: October 02, 2013, 03:46:49 pm
content: I've just got this high power RF amp functional

author: smashedProton
author_rank: Frequent Contributor
timestamp: October 08, 2013, 06:05:39 pm
content: I just got my ham license and my first radio!

author: AF6LJ
author_rank: Unknown
timestamp: October 08, 2013, 06:34:30 pm
content: I have a couple of projects in the works, an SDR transceiver kit that has been stalled for a while, other issues in life seem to have gotten in the way, including Oscar's rehabilitation, but Oscar is more important right now.You can meet Oscar here.http://forums.qrz.com/showthread.php?372651-SB-220-FindHere are a few pictures....As you can see Oscar came to me a bit modified, but gently built.The thread I posted a link to above has background information and a decent discussion on the work being done.Included in that thread are many more pictures along with a few of other people's projects.

author: alank2
author_rank: Super Contributor
timestamp: October 08, 2013, 07:31:41 pm
content: One thing I've got going is a project where I am converting the output from a iteadstudio gps shield (neo 6m) to the GPS stream that my Lucent RFTG needs so it will discipline itself. The second part of this project is a pid controller for the fan beneath the rftg, it varies the speed to try to keep the LPRO rubidium module inside at consistent temperature. It is a mess right now as you can see, but it has been running for almost 30 days this way. I've developed a pcb that I need to order that cleans things up a bit and I'm going to put an enclosure under the RFTG that hold everything and also blow air upwards to cool it.

author: alank2
author_rank: Super Contributor
timestamp: October 08, 2013, 07:34:58 pm
content: I've spent much more time lately on the reflow oven I've been working on.The oven is just a $40 oven from Walmart with convection. It has what look to me like quartz style heating rods, two on top 450W each and two on bottom 300W each. 1500W total. I love the door on it, it clamps the K thermocouple wire gently and holds it into place without putting any stress on it. Door stays open real easily and is soft to open and close (no board jerking).Easy to open up and rewire. I used some TGGT 250 deg C wire (not sure if I had to) for as much as I could and am using some 14/4 service cord between the oven and the SSR box. Why it is so thick looking for 14 gauge I don't know. Green = chassis ground, White = neutral, Hot = heater element, Black = fan and front oven light.The SSR box is aluminum and like the oven chassis also grounded. It has mains (120 VAC) coming into it and it uses two SSR's to switch the heat and fan/light wires going into the oven. The heating SSR is on a heat sink and I drilled some holes in the top and bottom of the aluminum box to let airflow cool it. The fan SSR is just mounted to the inside side of the box. I am using 1/8" minijack 3 conductor to connect the SSR box to the control board (sleeve=ground, tip=heat, ring=fan/light). This was the first time I machined aluminum on my CNC and it is much tougher than plastic especially with my weak Harbor Freight 1/4HP router. I messed it up slightly as you see in the picture, but it is functional.The control board right now is on a dip adapter I got from this guy a few months ago. Real nice guy who was kind enough to give me some reflow tips as well:http://www.mattairtech.com/index.php/development-boards/atmega32u2-usb-development-board-arduino-compatible.htmlAnd the max6675 on a dip adapter from eBay.In the end I am going to make a board in Eagle that has the atmega32u2 and the max6675 and supporting components only. I'm should be able to make it very tiny almost enough to make it a cable inline type deal where one end is usb to the PC and the other end goes to the SSR control box.The AVR is already running the PID algorithm, but not the reflow algorithm at this point, but with plenty of flash left I am toying with the idea of giving the AVR a very simple interface where you can select a reflow profile and run through. Not sure about that though.Next up is some PC software development...

author: 84GKSIG
author_rank: Regular Contributor
timestamp: October 09, 2013, 03:40:13 pm
content: Probably got too many unfinished projects going on at the same time to be honest but here goes...to the right is a hybrid low voltage tube/mosfet amplifier which runs on 12 volts pulls just over an amp, this prototype was originally going to be a headphone amplifier but impressed with how silent and low noise it turned out to be I then started using it as a preamp for my stereo amplifier which it sits on top of in that image.its case started off as a faulty external hard drive enclosurethe hybrid amplifier sits on top of a stereo amplifier which I built around a chip known as the LM3886, circuit is designed by my self with some guidance from the data sheet and about 5 months worth of good old experimenting with component values to get it to the point it's at today.came up with about 5 different circuits but now finally have one ive settled with.here's bad quality shot of the guts before installing the heat sinks and shielded input cable. ( still on the to do list as well as build another 3 of these and a couple more tube preamps and a DAC for the surround sound system!

author: delmadord
author_rank: Regular Contributor
timestamp: October 10, 2013, 04:31:52 pm
content: Here is one really bad quality photo of my "digitally controlled temperature regulator for old iron" for chemistry and lamination process in PCB manufacturing. Maybe even for solder reflow, I want to try it. It uses ATtiny44, 74HC595, rotary encoder and a 7-segment display. Mostly parts from my drawers. The iron was in my grandmother basement, lying around, so I took advantage of it. I started just few days ago, so it is only on breadboard (also I ned this to actually make PCB for it)

author: JeanF
author_rank: Regular Contributor
timestamp: October 11, 2013, 01:15:54 pm
content: Here is my ATMEL AVRISPmkII ghettoblaster : O0The hardware is from a pair of small amplified speakers, a Edifier MP300+ kit. I didn't like the fact that it was a 3-piece kit with bulky cables between the speakers and I wanted an all-in-one solution.There were also some feature that I wanted to change. The speakers don't have any power switch, but the board boots by default in a low-power mode (the TDA7377 is on standby) and you have to click on one of the volume buttons to power on the output stage. This is rather nice, but I wanted to use the speakers as alarm clock speakers (using the alarm clock from a phone or an ipod) so if there is a short mains cut in the middle on the night, they will boot in standby mode when power comes back, so not good to wake up. I made a small "dead bug style" board with a small PICAXE (I can't program in C yet) ; one of the audio input channels is hooked to an ADC pin via a AC-coupled opamp set to a gain of 100. The PICaxe detects when the audio signal is coming, and pulls high the standby pin of the TDA7377. When the song ends it's back in standby mode.There was also a SPI volume control chip that I removed because the main microcontroller (AT89C2051) used to reset the volume at its medium level at each startup, and since there is a volume control on the music playing device, this redundancy was, in my case, useless.All that, I guess, probably could have been done by reprogramming the AT89C2051 but I don't have any skills with that family so why bother... O0

author: delmadord
author_rank: Regular Contributor
timestamp: October 11, 2013, 02:09:04 pm
content: Quote from: JeanF on October 11, 2013, 01:15:54 pmI love the carboard caseThat caution sign looks like it should be there by design

author: SLJ
author_rank: Frequent Contributor
timestamp: October 11, 2013, 06:08:51 pm
content: Working on this vintage Non Linear Systems digital voltmeter form the 1950s. This "edge lit" display was the first type of digital display. Each digit was an engraved Lucite plate lit by a small lamp. The display was selected by a resistor dividing network and stepper relays.Video of display and relays working:Display Teardown:NLS 481 Digital Voltmeter DisplayEdit: Lucite plates not Lexan.

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 11, 2013, 06:15:04 pm
content: Quote from: SLJ on October 11, 2013, 06:08:51 pmOh man, that sound! Only suitable for measuring very stable voltages I'd say

author: SLJ
author_rank: Frequent Contributor
timestamp: October 11, 2013, 06:19:14 pm
content: Quote from: PA0PBZ on October 11, 2013, 06:15:04 pmFortunately there is a sensitivity control on the front panel otherwise the last digit constantly wanders unless the source being measured is rock steady.

author: 84GKSIG
author_rank: Regular Contributor
timestamp: October 11, 2013, 06:34:35 pm
content: that thing looks amazing and i want one! was that arcing on the board near the tubes??

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: October 11, 2013, 06:47:31 pm
content: Quote from: PA0PBZ on October 11, 2013, 06:15:04 pmThe noise that thing makes has a very sinister quality, not pleasant at all, and it clashes with the front panel esthetic. If you have a laboratory cat or dog I would imagine they would get freaked out by the sound.

author: Stonent
author_rank: Super Contributor
timestamp: October 11, 2013, 08:10:23 pm
content: Quote from: PA0PBZ on October 11, 2013, 06:15:04 pmMy father had a 1981 Nissan/Datsun 280Z (called Fairlady Z in some other countries) and some of the lights on the dash worked that way. I don't know of it used relays but it did use stacked engraved plastic with various symbols.

author: rexxar
author_rank: Frequent Contributor
timestamp: October 11, 2013, 08:21:29 pm
content: I'm trying to convince my boss to let me teach an electronics class for kids, so I put together a demo board with some projects we'd be working on.

author: SLJ
author_rank: Frequent Contributor
timestamp: October 11, 2013, 09:25:08 pm
content: Quote from: 84GKSIG on October 11, 2013, 06:34:35 pmThat's a reflection off a couple of neon lamps on the circuit board that fire on and off when the relays are in motion.

author: jancumps
author_rank: Unknown
timestamp: October 11, 2013, 10:03:40 pm
content: without words (because it's not going as smooth as I expected):

author: rexxar
author_rank: Frequent Contributor
timestamp: October 11, 2013, 10:30:02 pm
content: Quote from: SLJ on October 11, 2013, 06:08:51 pmHoly hell, that's impressive.I suddenly want one.

author: WarSim
author_rank: Frequent Contributor
timestamp: October 11, 2013, 10:35:10 pm
content: Quote from: delmadord on October 10, 2013, 04:31:52 pmI like this project the best, because he is making this project in order to make a project. I just think it is great that people still get the development chain.It's like patching together a 3D printer to print the missing parts of the 3D printer your are making them on.Only project in the last year coming close to this is several electronic loads to test the multi-output power supply I needed for another project.All the others are just items I couldn't find to buy or prove something could be done.

author: mtdoc
author_rank: Super Contributor
timestamp: October 11, 2013, 11:25:47 pm
content: Quote from: WarSim on October 11, 2013, 10:35:10 pmReminds me of....."In making the handleOf an axeBy cutting wood with an axeThe model is indeed near at hand."Lu Ji's Wen Fu, fourth century A.D

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: October 13, 2013, 07:48:22 pm
content: A 7 MHz 2 watt DSB voice transceiver capable of over 1000km range using discrete components (except for the LM386). Average power use is a few milliamps, allowing hours of use from a small battery pack.It was going to be a phasing method SSB radio but I took some shortcuts and ended up making it DSB. This is less efficient but is simpler to build. The video describes the construction, has circuits of additions made and gives it a workout from the local beach.

author: andtfoot
author_rank: Unknown
timestamp: October 14, 2013, 02:29:05 pm
content: Saved a Samsung LED LCD jobbie from being junked, so I'm just trying to fix it up now.I've done the usual cap replacement in power supply board, but still mostly no turning on. Just a blinking LED on the front and cyclic dropping of the rails.Bit of tinkering left to do methinks..

author: Cottees
author_rank: Newbie
timestamp: October 15, 2013, 12:33:50 pm
content: Here is a couple projects I am working on at the moment.LEDVis MiniThis is an ArduinoATMega328 based 'Colour Organ'. Designed to be an Arduino shield that contains the MSGEQ7s and the TLC5940 chips, and another shield can be put on top of that with LEDs, or connectors to LEDs or MOSFETs to drive higher power LEDs.A paper mockup of it. The final version is a little different.The final breadboard test.A mate's build of it using 3 RGB LED strips.Radio CabinetI wanted an old Radio Cabinet, but to have a DAB+ radio inside, and to look like it was meant to be like that. I found an old beaten up and gutted cabinet on Gumtree for $20, and started from there. At the moment I have planned out the hybrid tube/solid state amp with 84GKSIG. The 'brains' will be a Raspberry Pi with ATTiny84 based smart PSU.This is what it looked like when I got it.A quick mockup of the amp.The Mids and Tweeters installed.The Sub installed.Virtual layout in Sketchup.TinyTimerThis is being designed for 84GKSIG for his UV exposure box. It is Arduino-tiny/ATTiny84 based.The face plate I designed for it.Quick video testing some basic functions.All wired up for testing. Just need to finish the code, and get it all to fit onto a PCB.

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: October 15, 2013, 07:41:56 pm
content: I`m repairing a GSM remote controlled switch, small parts and old fragile plastic in the SIM card holder beeing removed and the card modified to a new metal card holder. And some parts (resistors and caps) that been fried by a lightning strike replaced.

author: marshallh
author_rank: Unknown
timestamp: October 15, 2013, 10:33:21 pm
content: inspecting pcb and resolving drill sizing errors with fab

author: Stonent
author_rank: Super Contributor
timestamp: October 15, 2013, 10:42:41 pm
content: I just build my very first soldering kit. The Velleman TV Tennis kit. I have not tested it yet because some of the solder pads are close enough that I can't tell if they were supposed to be joined or not. So I want to spend some extra time looking it over before powering up.It has a pic16 series chip on it and am hoping I can dump it so I can try other experiments on the board.My next project is the Velleman pic programmer board. I got both these from radioshack for about $11 total. If bought at full retail I'd have been out about $60.

author: AF6LJ
author_rank: Unknown
timestamp: October 21, 2013, 02:46:17 pm
content: Quote from: vk3yedotcom on October 13, 2013, 07:48:22 pmNice, a fun project...

author: TMM
author_rank: Frequent Contributor
timestamp: October 21, 2013, 03:28:35 pm
content: Finally got my AVR based distortion meter up and running - damn solder bridges on PCBs without solder maskResidual distortion is about 0.1%THD (up to 5th harmonic) over 48dB of dynamic range, not too shabby for the AVR's 10bit ADC, crude autoranging and powered off USB. Good enough for my purposes though as i just need to detect around 1%

author: Unknown
author_rank: Unknown
timestamp: October 23, 2013, 12:01:06 pm
content: Over the weekend I soldered on some more parts to my temperature controllers boards; In-between finishing this off I'm looking at a handheld digital multimeter project.

author: idolstar
author_rank: Newbie
timestamp: October 23, 2013, 03:02:11 pm
content: I'm a beginner/hobbyist, but I have a party coming up and decided to try my hand at making a pattern using 3 color LEDs with integrated ws2812 chips. I used a pic12f1822 to drive the chips. The pattern I am making is a rainbow that rotates through 256 LEDs.Here's a video of testing:http://youtu.be/TnBMJfVZohw

author: andtfoot
author_rank: Unknown
timestamp: October 24, 2013, 08:27:30 am
content: Currently figuring out how to make circuit boards on my CNC milling machine...Missed!

author: wraper
author_rank: Unknown
timestamp: October 24, 2013, 11:53:40 am
content: Just implemented a solder mask in my home PCB production facility.

author: marshallh
author_rank: Unknown
timestamp: October 24, 2013, 08:10:11 pm
content: Quote from: wraper on October 24, 2013, 11:53:40 amPretty impressive job!

author: rexxar
author_rank: Frequent Contributor
timestamp: October 24, 2013, 08:12:59 pm
content: Quote from: wraper on October 24, 2013, 11:53:40 amWow, that looks great!Quote from: andtfoot on October 24, 2013, 08:27:30 amOops.

author: dr.diesel
author_rank: Super Contributor
timestamp: October 25, 2013, 03:10:32 pm
content: Quote from: andtfoot on October 24, 2013, 08:27:30 amStore bought or DIY?

author: Alana
author_rank: Frequent Contributor
timestamp: October 25, 2013, 09:08:19 pm
content: My model railway clock - mainboard is finished, displays needs to be re-done properly but something works,i hope works enough to test how it behaves on 20+ meters of cable.http://youtu.be/zYhlzDLROe8And this is one of those "i hope your next project does not work" projects. I haven't had so much debuging since i started electronics.

author: andtfoot
author_rank: Unknown
timestamp: October 31, 2013, 07:53:19 am
content: PCB attempt Mk II... missed again (added locating pins, but forgot to offset the drill file.New one is the left one (I stopped it part-way after doing some testing).Meanwhile I'll just dream of being able to make them this good...Quote from: wraper on October 24, 2013, 11:53:40 am

author: richard.cs
author_rank: Super Contributor
timestamp: November 01, 2013, 04:42:45 pm
content: Six-digit frequency counter. OCXO or external clock, optional divide-by-1000 pre-scaler.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: November 01, 2013, 08:19:39 pm
content: I'm working on a high-current buck regulator.My 20A inductors just arrived!

author: Kibi
author_rank: Unknown
timestamp: November 01, 2013, 10:25:08 pm
content: I am doing some charity work. My sister's local church band has asked if I can repair their Marshall guitar amplifier.The amplifier plays, but most of the pots are either smashed or are "scratchy", so the whole lot are being replaced and new Marshall knobs ordered as most of them are missing too.The other thing I am working on is a CC3D flight controller for multirotor (probably a quadcopter, maybe a hexa). The CC3D is quite difficult to find and if you do manage to find one, they are expensive. Openpilot, being open source, allows anyone to build it themselves.I got the PCB's in the other day from iTead Studios.As always, one's feelings are much elated when one of these boxes arrives!The Americans at Digikey did get rather excited and started asking me a whole load of awkward questions surrounding the purchase of the Invensense MPU-6000. They wanted to know what I was building with it and why. Apparently it is a restricted export item, although it's originally imported from Taiwan, go figure.I don't think I'll ever get my head around the unique way in which Americans think.I'll probably order it direct from Invensense next time to save the hassle, although Digikey are doing it at a really attractive price.So, amongst the rest of the components, I have the Gyro / Accelerometer and the ST ARM. The components arrived some time ago, I was just waiting for the PCB's.

author: BurtyB
author_rank: Regular Contributor
timestamp: November 02, 2013, 03:21:18 am
content: I've been working on a USB hub, I know I could just buy one but there's no fun in that.

author: zapta
author_rank: Super Contributor
timestamp: November 02, 2013, 07:41:43 am
content: I am working on a hack that will start my car in Sport Mode. It uses a stock Digispark, software and wires. I wanted for some time to learn Arduino.https://www.dropbox.com/s/ow6ft1r8lwyqqud/sport_mode.mp4https://github.com/zapta/button-minder/tree/master/projecthttps://github.com/zapta/button-minder

author: SLJ
author_rank: Frequent Contributor
timestamp: November 02, 2013, 03:17:22 pm
content: My new dedicated SMD/ESD soldering station is almost complete. The microscope would take up too much workbench space so I decided to separate it from the main bench.Found a good quality Mayline roll-around computer desk (for under $100 US) that was a good size for the microscope and built shelves on it for the monitor and tools.It's a little newer technology than the soldering station hanging next to it.

author: xrunner
author_rank: Super Contributor
timestamp: November 05, 2013, 03:10:03 pm
content: A ham friend asked me to look into his Mirage 100W VHF amp. It failed because he accidentally input 20W.After a short while I found that the 2SC2094 pre-driver amp was bad. Looks like they run about $30 - $36 ea. Ouch.

author: Smokey
author_rank: Super Contributor
timestamp: November 05, 2013, 08:54:42 pm
content: Quote from: SLJ on November 02, 2013, 03:17:22 pmThat is a killer rework desk. Nice job!Once you get a Metcal you will be all set

author: GreyWoolfe
author_rank: Unknown
timestamp: November 05, 2013, 09:32:41 pm
content: I picked up a Wavetek 182A for $5 with the magic smoke let out of the transformer. There are some additional back components. you can see in the second picture that a Tantalum capacitor and a 5% resistor connected to it are black. I have the values from the schematic. Of course, the transformer is a custom part number and is made of Unobtainium, but I plan to substitute a 36VCT transformer and get the replacement through hole parts and see what happens, After that, I get to play with a Kikisui 60 MHz scope for a friend. It is nice to be relearning by doing stuff and not strictly reading.Tom, NW0LFI am probably embarrass myself asking this, but how are people putting full sized pics in the post. All I can make happen is the adding of the little attachment photos.

author: SLJ
author_rank: Frequent Contributor
timestamp: November 05, 2013, 09:58:43 pm
content: Quote from: Smokey on November 05, 2013, 08:54:42 pmOrdered a Hakko Desoldering gun today. Will be upgrading the station but haven't decided on a budget or what to get. The Weller works fine but would like to move it back to the main bench and get something more suited for micro-soldering. I tend to hold on to equipment for a long time. At least with Weller I have been able to get parts after 20 years. Not sure anything made today will be around in 20 years.

author: xrunner
author_rank: Super Contributor
timestamp: November 05, 2013, 10:59:04 pm
content: Quote from: GreyWoolfe on November 05, 2013, 09:32:41 pmHost the pics on another site and link to them in the post like this -Code:http://www.hostingsite.com/picxxx.png

author: david77
author_rank: Frequent Contributor
timestamp: November 08, 2013, 01:29:52 am
content: I've got a long term project going. I've started planning for this maybe 18 months ago.It's a small mixing desk for my home audio equipment. A modular design with a 12x5 input matrix, each of the 12 inputs has its own input amp, gain settable to match the output of the source. This matrix switch and the amps take up a whole 3HE 19" rack. At the moment I'm finishing the main mixing desk of the design. It involves a lot of wiring...very tedious I have to admit. But also is rewarding as analogue design, systems engineering and also some MCU design work is in thereThis project gets interrupted by other things regularly, most recently the repair of my new old function gen, the Exact 7060. It suffered from a burnt out output stage.And then I recently aquired another one of these lovely old Siemens scopes that needed a bit of TLC but works perfectly again now.There are more things in the pipe line - that is my head.

author: nanofrog
author_rank: Super Contributor
timestamp: November 08, 2013, 02:23:45 am
content: Quote from: SLJ on November 02, 2013, 03:17:22 pmIs that Beau-Tech soldering tools there (SH-20G & maybe an SH-20C)?

author: SLJ
author_rank: Frequent Contributor
timestamp: November 08, 2013, 03:07:07 am
content: Quote from: nanofrog on November 08, 2013, 02:23:45 amGood eyes. SH20A and SH20G.The solder holder was taking up space on the bench so I built one into the shelf over the hand tools and made a holder for the tweezers.

author: nanofrog
author_rank: Super Contributor
timestamp: November 08, 2013, 03:12:54 am
content: Quote from: SLJ on November 08, 2013, 03:07:07 amHandy little devils (entire series).Their nylon spudgers (SH-80) are great too.Ever tried dental picks? Might find them more helpful with SMD due to the smaller points.

author: SLJ
author_rank: Frequent Contributor
timestamp: November 08, 2013, 03:15:01 am
content: I use a dental pick most of the time. It's in the photo above. Might not be able to see it in the first photo.

author: nanofrog
author_rank: Super Contributor
timestamp: November 08, 2013, 03:28:59 am
content: Quote from: SLJ on November 08, 2013, 03:15:01 amPhoto didn't display when I posted.Quite handy little tools. Wax knives too (great for mixing small amounts of 2 part epoxies & the like for repair jobs, and toothpicks are great for applying it.

author: TerraHertz
author_rank: Super Contributor
timestamp: November 11, 2013, 06:22:28 pm
content: 'Electronics related' ... sigh. Well *distantly* related, I guess. In that it's all supposed to be so I can eventually get back to doing some electronics.http://everist.org/NobLog/20131021_Logic_Analyzer_furnace.htm

author: tehmeme
author_rank: Regular Contributor
timestamp: November 12, 2013, 11:14:35 am
content: Quote from: TerraHertz on November 11, 2013, 06:22:28 pmSome pretty nice looking work right there.

author: marshallh
author_rank: Unknown
timestamp: November 13, 2013, 02:09:48 am
content: about to smoke test this little guy

author: TerraHertz
author_rank: Super Contributor
timestamp: November 13, 2013, 06:13:54 pm
content: Quote from: marshallh on November 13, 2013, 02:09:48 amYou're just going to wait till someone begs you to explain what it is, aren't you?Sadist.....OK, what is it, please?Your design presumably? Nice work.Without looking up chip numbers, I guess PCIe PC card, with an RJ45 gigabit ethernet, but what's the flex ribbon connector for? LCD display? So it's some dedicated system based on a small PC motherboard, with a built-in LCD, and a lot of networking grunt?

author: Anks
author_rank: Frequent Contributor
timestamp: November 13, 2013, 06:56:55 pm
content: Repairing a MESA BOGGIE dual rectifier.

author: codeboy2k
author_rank: Super Contributor
timestamp: November 14, 2013, 01:12:02 am
content: Quote from: TerraHertz on November 13, 2013, 06:13:54 pmI am pretty sure it's Marshall's work, he's always done good looking boards like that...I see PCIe-x1 , then what I thought was Ethernet at first, but looking closer I see a TI TUSB chip, maybe a TUSB3410 but it's not, it's a new one to me, TUSB1310 I think.. Now I see a USB port and it's blue.. so that's USB 3.0 ... There's another port made in China, I have no clue, maybe that's an Ethernet port, but I don't see the magnetics so I am not sure. I see a Lattice ECP3 FPGA (love that chip so much! ), an LCD flex connector, and some DDR3 DRAM from Micron.I also see a board I want to buy, because I can use a general purpose board like that..

author: Rufus
author_rank: Super Contributor
timestamp: November 14, 2013, 03:28:55 am
content: I can't post much of what I work on but this is sufficiently obscure. A 3mm square DFN accelerometer dead bugged on top of a 14 pin DIL.

author: BravoV
author_rank: Super Contributor
timestamp: November 14, 2013, 06:52:44 am
content: Quote from: Rufus on November 14, 2013, 03:28:55 amDamn .. I cringed when I saw that, especially I don't have any magnifier tool and my eyes now hate DFN package.

author: hans
author_rank: Super Contributor
timestamp: November 15, 2013, 10:01:41 am
content: Writing some HW test firmware (loading lots of demo apps..) on my Power Analyzer project:Purpose is to measure low-power consumption for battery applications. So the common mode voltage of the DUT terminals is +/-12V or there abouts, ranging from uA's to A's.The board contains a 1R or 10R (selectable) shunt resistor, AD8253 programmable instrumentation amplifier (1-1000x gain), some signal conditioners, and a low-speed >16-bit MCP3911 A/D. Voltage/current signals are also fed to the STM32 12-bit A/D for faster capture, however that disappoints above 3 MSPS (crazy noise between each sample).STM32 is connected to a host PC via USB or a KSZ8051MLL ethernet Phy. Bottom of the board contains a 4Mbit SRAM, too.

author: DutchGert
author_rank: Frequent Contributor
timestamp: November 15, 2013, 11:31:39 am
content: Got some pictures of the board I designed last year to test CubeSat's.So I am using my lunchbreak to drool over them

author: mathsquid
author_rank: Frequent Contributor
timestamp: November 18, 2013, 02:13:19 am
content: I'm building an AVR-based CNC controller, and putting it inside an old computer case.

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: November 24, 2013, 01:35:30 am
content: Quote from: marshallh on November 13, 2013, 02:09:48 amI was going to guess that it is it is USB 3.0 sniffer but I only see one type B USB 3.0 jack and SINGLE port TUSB 1310A USB 3.0 transeiver.I only see one clock source - 26MHz for TUS1310A but none for FPGA so perhaps board is double sided loaded with more magic on other side?

author: senso
author_rank: Frequent Contributor
timestamp: November 24, 2013, 02:43:44 am
content: Quote from: marshallh on November 13, 2013, 02:09:48 amWhy the change from OSHPark?They couldn't honor their limits?

author: cloudscapes
author_rank: Regular Contributor
timestamp: November 25, 2013, 03:23:35 pm
content: This audio effect/mangler here. I make these kinds of things for musicians who are more inclined towards the experimental, like myself. so no comment needed on how "broken" everything sounds.It's on-purpose.PIC32 powered, using a 12bit MCP3201 ADC and 16bit PT8211 DAC. I use the pic's internal memory for sampling, 32,000 samples worth. The ADC is limiting, and I've been trying for a while to interface to a legit audio codec. I'm considering moving over to ARM as there's more audio support and peripherals. Plus they just look overall better for the parts that interest me.PCB designed in diptrace, fabbed by osh park.The video is non-technical. It's just a demo video for potential end-users.

author: TerraHertz
author_rank: Super Contributor
timestamp: November 30, 2013, 04:38:37 am
content: More 'mechanical crap masquerading as electronics':http://everist.org/NobLog/20131122_an_actual_knob.htmOr should I call it a teardown of a HP 80000 1GHz data generator?

author: delmadord
author_rank: Regular Contributor
timestamp: December 14, 2013, 05:41:46 pm
content: Quote from: WarSim on October 11, 2013, 10:35:10 pmHi, thanks for your acknowledgementYou know, it is easy to just buy stuff you need if present, but when it comes down to solution that don't exist yet or is overpriced, you can learn a lot by making your own project for your projectand sure, it is fun too

author: SLJ
author_rank: Frequent Contributor
timestamp: December 31, 2013, 09:18:20 pm
content: Just in time for the new year, this tube/valve tester from 1941 arrived today:The meter is huge.Needs a new cord, a cap, and some cleaning but everything tests good so far.

author: jancumps
author_rank: Unknown
timestamp: December 31, 2013, 09:58:02 pm
content: I'm in learning mode,finding out how to work with ARM Cortex and specificaly how the safety features of the TI Hercules processors work (including a redundant lockstepped ARM R4 core).

author: nanofrog
author_rank: Super Contributor
timestamp: December 31, 2013, 10:36:25 pm
content: Quote from: SLJ on December 31, 2013, 09:18:20 pmShould be a beautiful addition to your collection once you're done with it.I'd love to see what it looks like once you're done. Hint, hint.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 01, 2014, 03:55:21 pm
content: The new year brought me something retro-cool too. A HP 1607A Logic State Analyzer, from 1979-ish. An example of a very early stage of Logic Analyzer evolution. This thing is not much more advanced than a logic probe. It doesn't even have its own display.What's neat about it, is how it displays the captured data. It has BNC X,Y & Z outputs. These can be connected to a scope or other CRT display capable of working in X-Y mode. The 1607A draws ones and zeros on the screen by outputting analog waveforms. It can draw a grand total of 16 words of 16 bits each. Which is its entire capture memory.This is much like the Tektronix 7D01/DF2 units, which also drew characters on an XY screen. Except this is much cruder than the 7D01, even though a few years behind Tektronix. It can't even display anything but binary. No HEX or Octal, though it can display bits in columns of 4 or 3.In the pics below I have only just set it up. It has some problems, such as the inter-character blanking isn't working, so you see squiggles on the XY screen between the characters. The output is displayed on a Tektronix 620 XY monitor. Just random 1s and 0s so far. The Tek 1240 logic analyzer is there to provide a known test pattern data output.This is just for fun and my 'old logic analyzers' collection. In practical terms today it's completely useless.

author: xrunner
author_rank: Super Contributor
timestamp: January 01, 2014, 04:12:52 pm
content: This is a bit of a double-post (because I forgot this thread was here), but I made a little circuit to cut off the long wire antenna from my up-converter/SDR dongle when I transmit with my FT-450. It's pretty simple being a single transistor and relay and LED (because I have too many LEDs and I need to use them, but does the job. It uses a signal line from the FT-450 out of the linear jack which merely goes to a open collector transistor in the rig.I don't think the transmitted power level will damage the up converter, but it does look like I just detected the EMP from a nuclear bomb on the computer screen when I transmit.

author: niekproductions
author_rank: Contributor
timestamp: January 01, 2014, 04:20:48 pm
content: Just ordered the PCB for my nixie clock

author: SLJ
author_rank: Frequent Contributor
timestamp: January 01, 2014, 04:25:36 pm
content: Quote from: xrunner on January 01, 2014, 04:12:52 pmNice one. Reminds me that one of these days I need to build a trimmer for tuning a long wire for receiving. Right now it's just 75 feet running across the celling in my office. Works but a trimmer should help cut down on some of the noise.

author: Kjetil
author_rank: Regular Contributor
timestamp: January 01, 2014, 09:24:46 pm
content: My main project at the moment will be a custom 3d-printer, somewhere in the line of the one in EEVBlog #520. Most of the components have arrived or are in transit. I still need to manufacture the frame and design/print most of the plastic plates. The design philosophy will be: " This is a vacation, if anyone has designed this piece before, I will redesign it"What I have for now:Electronically:Arduino MegaRAMPS 1.4 with driversLots of stepper motorsHot-end arrives tomorrowEndstopsMechanically:Need: 25x25 aluminium tubes (aquarium stands)Need: 8mm axel steel/threaded rodsOrdered: Belts and pulleysHave: bearingsHave: boltsHave: toolsApparently I couldn't upload photos here, but more will come later, nothing much interesting to see so far anyways.

author: deth502
author_rank: Frequent Contributor
timestamp: January 01, 2014, 10:39:34 pm
content: Quote from: Anks on November 13, 2013, 06:56:55 pmvery nice. imo, best sounding heads out there.

author: c4757p
author_rank: Super Contributor
timestamp: January 01, 2014, 10:41:20 pm
content: Quote from: niekproductions on January 01, 2014, 04:20:48 pmThe ground plane clearance on that board looks a little tight.... what is it, 0.3mm? 0.4mm? And you've got 200-300V on those traces?

author: TerraHertz
author_rank: Super Contributor
timestamp: January 02, 2014, 01:03:33 am
content: Quote from: c4757p on January 01, 2014, 10:41:20 pmFor neons it's more like 50 to 80V I think? But even so, too close. There'll also be higher voltage on the other side of the current limiting resistor.Another thing - aren't the nixies supposed to be in sockets? What kind of round socket has lugs small enough for those PCB holes?

author: Rerouter
author_rank: Super Contributor
timestamp: January 03, 2014, 02:45:17 pm
content: I'm currently working on a AD9850 DDS based function generator + sub 100Khz counter (arduino based is a given) for automotive cluster testing, powered off 4 Nimh batteriesThis project has been on hiatus for close to a year and while bored over the holiday break picked it back up and now is approaching completion, still finding myself trying to fight off feature creep (really want to add a CAN Bus transceiver to it)Currently I've got the counter side interrupt based, and it happily counts all the way up to 255Khz (way past my 25Khz requirement), with the input conditioning being a biased AC coupled transistor which pulls down an RC network at the input to a schmitt trigger,The AD9850 module is working beautifully, though i have had to modify the code to implement power down modes, and to speed it up with bitwrites as opposed to slow digitalwrites, for anyone playing around with one of these, i recommend the code from here nr8o.dhlpilotcentral.com,In software I've added ramps / sweeps, and step patterns, plus ratio calculation and a few things very specific to "tachographs" (they use switches to set calibration and rather than add a look-up table i burnt a good 2 days working out the curve between binary switch value and pulses per km)The main outputs of this will be an open collector (hall effect), and what we term crossing zero (+-1 to 20V), and i feel glad to brag that it is built like a brick shit-house with every output getting a high wattage TVS diode and a PTC clamping at 200mA, I did go out of my way to try and keep all the protection ground referenced, as that means no voltages can be fed into the low current supply rails i am using. I even went as far as using an optical analog switch to physically disconnect the output of the crossing zero op amp when it is not powered (can and will be hooked up to 12/24V supply rails regularly and with a +- output could not come up with much better)For the crossing zero output it needed a hard current limit of 50mA and ended up using a OPA547, its a great chip(you set the output current limit with a resistor), though voltage limiting i chose output called for raising the supply rails to +-28V so that i could be confident the TVS would hold off on the normal 20V signal, but trip before it exceeded the supply rail,And i will admit i am not happy with the amplitude control of the crossing zero output, but without adding an additional op am i could not see how to add it (have to sum with negative pull-down to make it zero centered, then adjust the amplitude to ground) though i may change this later, for the moment its not my greatest worry as its what our current 25 year old (failing max038 chip) function gen uses.this has also been my first knee deep adventure in to switch-modes, and i have used ti's webench as a crutch simply designing with the values it spat out and then tying on disabling circuitry to the amplifier supplies (when not in use that whole section will be powered down)I've gone ahead and attached the I/O part of my schematic (in progress) if it can be improved, please point out a suggestion(the AD9850 pinout does not match as i am simply fitting a DIL socket for a cheap ebay module

author: kebogen
author_rank: Contributor
timestamp: January 04, 2014, 01:40:05 am
content: wow,it looks great.

author: Spikee
author_rank: Frequent Contributor
timestamp: January 04, 2014, 03:03:55 am
content: I have designed the multicopter board for a college project. We have to design and implement the electronics of an autonomous (vertical) flying toy heli:This board has been reflowed by now and tested. The only fault is a 0603 metric led instead of 0603 imperial (a colleague of mine) .Chips on the board:STM32F0 tssop 20 micro.2x2mm QFN 1S lipo TI tps62291 buck DC/DC converterInvensense MPU6050 (accel , gyro and external HMC5883L magneto.)MS5611 precision barometer/temp meter (we get better than 10cm accuracy)3 logic level mosfets to drive the rotor's and possibly the tail.Second board is an experimental TI CC110L ULP rf transceiver for the 300 – 348 MHz, 387 – 464 MHz, and 779 – 928 MHz frequency bands:I only need a few 0603 caps and i can also test this board.And like always i'm working on 3 more boards/projects.

author: WarSim
author_rank: Frequent Contributor
timestamp: January 06, 2014, 04:38:33 am
content: Quote from: c4757p on January 01, 2014, 10:41:20 pmVoltage entirely depends on size ergo plate spacing.But yes almost every old school NiXi was 90 to 180 V.Since the the spacing is so small, hopefully Niek is using one of the low voltage tubes.Sent from my iPad usingTapatalk

author: niekproductions
author_rank: Contributor
timestamp: January 06, 2014, 02:20:22 pm
content: Quote from: c4757p on January 01, 2014, 10:41:20 pmOh crap, I knew I forgot somethingIt's 0.4mm for 180V. According tothis, I should still be able to get away with it. Luckily the board is for my own use.

author: niekproductions
author_rank: Contributor
timestamp: January 06, 2014, 02:22:51 pm
content: Quote from: TerraHertz on January 02, 2014, 01:03:33 amThere's 180V on the power trace, and about 50V over the anode resistor. I'm using IN-14 bulbs, they don't have sockets.

author: Rerouter
author_rank: Super Contributor
timestamp: January 06, 2014, 02:26:18 pm
content: Quote from: Spikee on January 04, 2014, 03:03:55 amOnce you get it running, care to tell us how stable you can get the thing, i own the exact same model, and even the throttle varies at random.

author: Spikee
author_rank: Frequent Contributor
timestamp: January 06, 2014, 04:53:26 pm
content: Quote from: Rerouter on January 06, 2014, 02:26:18 pmI built another prototype for this application using a Cypress Psoc 4 and it worked quite good. The hard thing is to get a decent stable non drift value from the barometors.The Freescale MPL3115A2 gives +- 0.5 meters accuracy and is constantly jumping around in this region. The ST XXX is also quite shit tbh.Good barometers are the BMP 180 from Bosch (+-5cm) and the MS5611 from Meas-Spec (the best +-2.5 cm accuracy but hard to get).These toy helicopters have a mechanical gyro so additional electronically stabilization is not needed for the most part.We have the older prototyping running , we only need to trim the z-axis so it doesn't keep spinning XD. But that should be an easy fix.When we have it running decently i will post a video on my youtube channel and release the schematic , code and gerber files.

author: Rerouter
author_rank: Super Contributor
timestamp: January 06, 2014, 11:37:25 pm
content: Thank you very much

author: Spikee
author_rank: Frequent Contributor
timestamp: January 07, 2014, 12:03:57 am
content: I just tested my reflow oven (YouTube video is uploading) and used the first prototype multicopter board as a test case.I tried cleaning the Psoc 4 micro (big TQFP) but my IPA won't do that much =/This board has the:Cypress PSoc 4 micro (system on chip with analog blocks , opamps ...) :http://www.cypress.com/psoc4/TI TPS62291 2x2mm 1C lipo buck converter 1A max :http://www.ti.com/product/tps62291FDN something something mosfets (way oversized)ST L3G20 3-axis gyro (the square LGA-16) :http://www.st.com/web/catalog/sense_power/FM89/SC1288/PF252443LS331XXX Accelerometer :http://www.st.com/web/catalog/sense_power/FM89/SC444RGY led (left middle of the TQFP it is small...)And of course a lot of passivesUpdate:My video is available on my YouTube channel in my signature. "Testing DIY convection reflow oven" is uploaded.

author: zapta
author_rank: Super Contributor
timestamp: January 13, 2014, 07:15:32 am
content: I am working on developing a linbus stack for Arduino. This is my second Arduino project and it is based on Arduino Pro Mini. I have two goals in mind:1. Having an arduino based sniffer with a single linbus interface that detects the linbus frames sends them out to a computer via USB/Serial. a minor variation will have digital signals based on certain frame patterns (e.g. door_is_opened).2. Having an arduino based proxy with two linbus interfaces that will connect between the master and slave and will manipulate the bits (e.g. injecting a simulated button press).A prototype of #1 is pretty much working and I am already sniffing the bits in my car. To enable proxying with 1 bit latency I am not using hardware serial for the linbus. Instead it is bitbanged by an ISR with a very string interrupt usage policy. The linbus ISR is the interrupt in use, every else is interrupt free and I never disable interrupts. This gives a very low ISR jitter and I tested it with the full bit rate supported by the linbus standard.Here are a few picturesMy desk: you can see the board, Saleae logic analyzer, Microchip Linbus analyzer/generator, Mac (Arduino IDE and Saleae), and A Windows machine (Microchip analyzer requires Windows).A closeup of the board. You can see the Aruino Pro Mini, FTDI USB/Serial, and a ata6663 on an adapter board.The bottom side of the board. I am using a wirewrap wire and a wirerap tool to make a few turn around the pin and then solder it.The current schema. I may flatten the Arudino and FTDI USB/Serial boards and layout a single PCB with the 'discrete' components.The Mac screen. It has the Saleae analyzer, Arduino IDE and a console with a python script that reads the frame from the USB/Serial and show bit changes.A close up of the python script output. Frame id 20 has 4 bytes and each time a few changes. I use it in my car to reverse engineer the frames, I turn things on and off and see what changes in the frames.The Saleae logic analyzer. The first signal is the linbus input. The other ones are debugging signals from the Arduino.The Microchip linbus analyzer/generator. I used to to generate linbus frames while developing. This way I don't need to do debugging in the car.The Microchip linbus analyzer/generator. Microchip has many linbus related offering. When I look at one of the slaves in my car, the linbus transceiver is an Atmel chip but the controller is a PIC.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 13, 2014, 08:49:22 am
content: Restoring and trying out a General Radio audio oscillator type 813-A, from 1935.An article about the model here:http://www.ietlabs.com/pdf/GR_Experimenters/1935/GenRad_Experimenter_May_1935.pdfPics are after cleaning it up. Originally it looked more like the one here:http://www.radiomuseum.org/r/gener_raco_audio_oscillator_813_a.htmlQuite a pleasant surprise to find it works, and the frequency still matches a cal label from 1938!

author: Poe
author_rank: Frequent Contributor
timestamp: January 13, 2014, 03:08:35 pm
content: Quote from: Kjetil on January 01, 2014, 09:24:46 pmWould love to see someone use cheap brushless DC motors and put the money saved into absolute encoders. I have no first hand experience, but my guess is that the entire 3D printing experience would improve if there was a feedback loop.

author: rolandpenplotter
author_rank: Regular Contributor
timestamp: January 13, 2014, 11:12:59 pm
content: I'm building an "Arduino" out of valves...

author: Codemonkey
author_rank: Regular Contributor
timestamp: January 15, 2014, 08:57:34 pm
content: I've been working on a wireless thermostat for a while now after the one I had fitted a few years ago crapped out. The old system comprised of a battery powered thermostat with LCD which sent messages via RF to a mains powered receiver which in turn switched the boiler heat demand on or off. Unfortunately it always a bit crap. The battery powered bit only ran for a max of about 3 of months at a time on 4 AA cells which in itself is pants, but then to top things off the mains powered bit died (suspect its a cap that's aged as its uses them to drop the mains down to power the receiver and relay).So, I figured I could do better, and since I work with 802.15.4/ZigBee stuff on a daily basis that was an obvious choice as a starting point. Over the course of a weekend I knocked up a hasty prototype using evaluation boards to get the heating back on and keep the Mrs happyThe results of that can be seen below:Eval board running the prototype code (old thermostat below it in its usual state, wanting more batteries)Botchtastic mains powered bit to switch the boiler on/off. A bit rough but it worked fine for a few months until its replacement got built.I then started designing some boards to tidy things up a bit. All boards done in Kicad. The boiler control board was sourced from Mitch at Hackvana and the Thermostat board from seeedstudio. Didn't have a problem with either and quality was fine.Thermostat board. Not many parts, just reverse polarity protection, a navigation switch, TMP102 temperature sensor, NXP wireless module and an LCD module. Dropped a bit of a clanger with the connections to the LCD module, but a bit of work with the scalpel and some thin wire soon sorted thatMounted in its case. Its an odd shape since the battery compartment occupies much of the interior when the 2 halves are joined, not much room for the LCD module:All together with a couple of keyhole slots cut into the back for wall mounting:and a laminated legend to finish the front off:Fitted to the wall and running the heating:Boiler controller board in its enclosure (the buttons are for manual override of heating control):And finished off running the heating:There is also an external temperature sensor (another wireless device) which is currently another eval board. I've designed another board for that but not received it yet.I went through a few iterations of the software, ultimately settling on the following scheme which just uses the basic 802.15.4 MAC features, its not running ZigBee though I might switch to it one day, or I might write my own stack (already done one partially but not yet finished):The boiler controller acts as the network coordinator since it is always on and mains powered. It also makes the decisions about boiler on/off. It doesn't do any fancy PID control, just a simple 1 degree deadband control. I'm happy to put up with the temperature in the house fluctuating a bit to reduce the time the heating is on and save money for more toys.The external temperature sensor wakes once per minute sending its reading to the boiler controller.The thermostat sleeps mostly, waking up briefly once per minute to send its temperature measurement to the boiler or is woken on DIO state change if the navigation button is moved to change the setpoint. It also requests in return the average internal temperature (the system can cope with >1 thermostats), the external temperature, the demand state (heating on/off cooling on/off), the setpoint (if changed by another thermostat), and the percentage of time that heating or cooling has been demanded in the last 24 hours (handy for seeing if any changes done around the house affect the gas use). The current consumption is dominated by the LCD module which draws about 500uA I think. Both the wireless module and temperature sensor combined consume less than 5uA less when sleeping. With the 2Ah batteries, life should be a far bit better than in the system I replaced.I then decided to add some datalogging so finally found an excuse to get a RaspberryPi and do another board:This requests the temperatures and demand state once per minute and logs them in an SQL database. I then added a web front end to the data logged using all this new fangled Javascript and JSON stuff which really hurts my head which functions much better with C. The results of that can be seen here. If you click on the bit that says Heating Demand, it overlays the plot with the periods where the heating was on:http://indigopepper.com:8800/daily.htmlEventually I plan to add more sensors (have already designed a board with footprints on for a multitude of other sensors) and also add web/internet control and time scheduling to the heating system (may involve doing another rev of the boiler control board with a real time clock on it).

author: BillyD
author_rank: Regular Contributor
timestamp: January 15, 2014, 09:21:13 pm
content: That's a very professional looking end product indeed, well done!Can I ask where you got the enclosure for the thermostat?

author: PA0PBZ
author_rank: Super Contributor
timestamp: January 15, 2014, 09:23:51 pm
content: So what happened at 17:45, you started cooking? And why did the setpoint drop?

author: Codemonkey
author_rank: Regular Contributor
timestamp: January 15, 2014, 09:26:24 pm
content: Quote from: BillyD on January 15, 2014, 09:21:13 pmThanks :-) I got the enclosure ages ago, think it was from Hammond.

author: Codemonkey
author_rank: Regular Contributor
timestamp: January 15, 2014, 09:28:59 pm
content: Quote from: PA0PBZ on January 15, 2014, 09:23:51 pmI took it off the wall and opened it up to take these photos! I had it on my desk under a lamp so guess it warmed up.

author: PA0PBZ
author_rank: Super Contributor
timestamp: January 15, 2014, 09:39:56 pm
content: Quote from: Codemonkey on January 15, 2014, 09:28:59 pmOk, that explains the temperature rise, but the setpoint drop? Did you press a button accidentally?

author: Codemonkey
author_rank: Regular Contributor
timestamp: January 15, 2014, 10:20:09 pm
content: Quote from: PA0PBZ on January 15, 2014, 09:39:56 pmYes, when putting it back together!

author: arcom
author_rank: Contributor
timestamp: January 16, 2014, 11:17:11 am
content: Lately I've been spending a lot of time on an improved stair lights controller since the old one got "acquainted" with waterOriginal design had 20 PWM channels (open-drain using BS170 mosfets; no protection whatsoever) and an RS485 link, all powered by a single PIC16F877A. RS485 link was supposed to be for integration to the rest of the home automation system but then I dumped the RS485 and switched to CAN instead. In addition to that it also had 2 digital opto-coupled inputs for interfacing to the top/bottom PIR sensors.New design has 24 PWM channels with protected outputs (BTS711 high-side switches), CAN interface, 4 digital and 2 analog inputs (with overvoltage and transient protection) and uses three PIC16F722A MCUs as PWM controllers and one PIC18F45K80 for the rest (I/O, sequences/animations, CAN/UART communication, etc.). Here are a few pictures of the PWM driver prototype using PIC16F876A since I had them in my parts bin:Driver connected via I2C bus (excuse the chaos on the table):Picture was taken just before I connected the other driver to the bus.Board on the left side with the 2 blue LEDs lit is acting as the temporary controller. It's part of my home automation project which is still in development...for two years now...PWM driver PCBs have arrived and I'm still waiting for the controller PCB which should arrive in a day or two. Hopefully I will have a fully working unit by the end of this week.

author: TMM
author_rank: Frequent Contributor
timestamp: February 05, 2014, 10:11:56 am
content: My audio amplifier dyno is coming along nicely. Still a WIP but now semi-functional.It's basically a 1600W programmable resistive load (1,2,4,8,16 ohm) and an AVR powered FFT analyzer. Usable input voltage range is about 1-150Vrms @ <0.1% residual THD. Still needs a few more hardware features (fan control, resistance measurement, temperature sensors) but i'm taking a break from hardware and starting work on software :p

author: zapta
author_rank: Super Contributor
timestamp: March 30, 2014, 04:24:37 am
content: In the last few months I played in my spare time with LIN bus hardware and software. My motivation were a few mods that I wanted to make it to my car. When I started I set a few progressing milestones and recently I had the last one working.This is a small board can intercept LIN bus signals, apply logic, and when needed inject signals back to the bus. In my application it waits for the ignition-on state and then injects a signal to switch the car to Sport Mode. It also monitors the bus for certain car's button sequences that are used to toggle its functionality on/off (persisted in eeprom, useful before visiting the local dealer).Here are the main requirements I had* Inexpensive - it is based on an ATMEGA328P, a two layers PCB with matching OshPark design rules, and a bunch of standard components.* Easy to assemble by hand at home - it uses 0805 and larger components.* Easy to install the tool chain and modify the design - the board is compatible with standard Arduino IDE and the schema and layout were done with Eagle.* Customizable - adapting the logic to other applications is easy. Just follow the provided example and modify the code as needed.* Self sufficient - the board can also act as a LIN bus analyzer, dumping all the bus frames to a computer. No need for extra analysis tools.The schematic of the injector is here:https://github.com/zapta/linbus/blob/master/injector/eagle/injector.pdf?raw=trueThe project is opened sourced here:https://github.com/zapta/linbusBTW, I was surprised how little open source stuff is available for LIN bus (as opposed to let's say CAN bus) considering that every modern car has a few of them and it is supported by major IC manufactures.

author: 8086
author_rank: Super Contributor
timestamp: April 27, 2014, 06:33:01 pm
content: Cat tracking device, took it for it's first outing today. This version is only a logger but the next will feature a real time radio link.Oh, and this test was in the car, without the catMore info and some pics here (google docs):http://tinyurl.com/nn6dhyf

author: Arp
author_rank: Unknown
timestamp: May 01, 2014, 08:41:33 pm
content: Making a 16x16 pixel art display with some WS2812B and a plastic ceiling ventilation grid. Still have 3 more boards to go to fill it, and not really sure what I will display but that's for later me to figure outPosted a write-up on interfacing the leds with a pic32mx (http://blog.gitmi.com/interfacing-a-ws2812b-rgb-led-with-a-pic32mx250f128b/) for future reference

author: mrsniper011
author_rank: Newbie
timestamp: May 03, 2014, 03:30:49 pm
content: Working on a fresh smelling pcb design!

author: djacobow
author_rank: Super Contributor
timestamp: May 03, 2014, 05:01:26 pm
content: This thread is amazing. I am impressed by the ambition of you guys. My projects are much more modest.I have a few projects in flight at once, perhaps because I never finish anything.The first is an Arduino controlled lamp dimmer. It's configured right now to work as a dimmer/timer for getting the kids to sleep. It starts out at a preset brightness and fades to another preset brightness (or off) over a specified time. Board also has a place for an NRF24 module for wireless control.There has been a lot of learning regarding how to make this safe and robust, and I'm sure I'm still learning. One nagging annoyance is that for projects that touch AC, using a plug-pack power supply seems ridiculous, but open frame and board mount PSUs seem too pricey. I probably could put my own simple switcher on the board, but I have never designed one and it seems like a frustrating hassle.The second is a another dimmer approach. Similar scheme, but the dimmer itself is a FET-inside-a-bridge arrangement rather than a simple triac. It can therefore do reverse phase dimming like a triac, but also forward angle and "sine wave" PWM dimming. What I learned is that for the extra complexity, you do get the flexibility to change the behavior to better suit the type of load (incandescent, CFL (magnetic or electronic ballast), LED) but the actual improvement in performance isn't worth it, probably. Also, with the PWM you get a lot of noise which requires expensive parts to filter. PWM also requires an interesting snubber. Not only must it suppress voltage spikes, but seeing as they are coming fast and furious, there is significant energy to absorb, too.In the same vein of power electronics, I'm building a 4 outlet power strip that can be controlled wireless over WiFi. Again, using someone else's module, this time a SparkCore. The strip also has current sensors (ACS712) from with the uC can calculate an RMS current and therefore be able to report if the load in that plug is actually drawing current. I haven't written much software yet, but the idea is that you could build in logic, such as "if the TV in outlet 1 turns off, wait 10 minutes and turn off the set top box, etc". This is my first project with SMD. Using 0805s. Of course, I forgot to order the transistors, so I used some leaded components with their leads bent to make feet. And that's not even the worst bodge on this board. I used the wrong SOIC footprint for the current sensor. It's way too big. Worse, there are cutouts under the footprint, so connecting the current sensors is ugly. Here you see two different, but equally ugly approaches. Bodge city.Finally, just yesterday started breadboarding a "clap" detector. I wrote some software a few weeks ago that took the clapper to a new level. Instead of being merely able to determine a clap or two to turn a light on, I can quite readily discern arbitrary patterns, like "shave and a haircut" or the first bar or two of common musical themes. The idea is to assign commands to songs and give more clap flexibility. Can be added to any of the designs above. Getting a circuit to pick up claps but not to reject most everything else, including loud music and speech, and not to trigger on echos will be tricky. Actually, I think I'll just deal with echo triggers in SW.-- dave j

author: TiN
author_rank: Super Contributor
timestamp: May 04, 2014, 11:00:08 am
content: Trying to hack Nikon battery identification for EN-EL15, as I want to use AC brick to power my camera.Tomorrow should get broken DSLR body for repair and teardown

author: peter.mitchell
author_rank: Super Contributor
timestamp: May 04, 2014, 11:19:20 am
content: Quote from: TiN on May 04, 2014, 11:00:08 amI took the easy route, pulled the cells out of the battery and hooked up a supply to the battery contacts.

author: nuhamind2
author_rank: Regular Contributor
timestamp: May 04, 2014, 01:10:38 pm
content: Working on my graduation project. Not too special, just AVR based VGA controller. I use mega328 and able to display 64x32 character.

author: zapta
author_rank: Super Contributor
timestamp: May 04, 2014, 04:07:22 pm
content: This is my latest contraption, it measure the current consumption over time (=charge) of a battery operated equipment.Optimizing firmware of battery operated devices for long battery life requires accurate measurement of the power consumption patterns. The recommended equipment was a ~700 product that is very capable but also complex to use so I decided to built this little thing. It connects to a standard 5V USB charger on one hand and to the tested devices on the other hand (with battery disconnected) and it measures, analyzes and report via a USB/Serial connection. The device is optimized for measuring charge (current over time) and uses a coulomb counter instead of a A/D (it also has current and voltage A/D which are currently ignored by the firmware). General accuracy is ~1% and it reports both the raw data and the results of a simple analysis it does (e.g. standby power vs on power).The button resets the integration values, the dip switches select the analysis and reporting format and the small header at the front is the power output to the device and operation can be as simple as observing the analysis results on a terminal.Firmware was developed using the Arduino IDE (the device looks like an Arduino Mini Pro) and PCB using Eagle. The form factor is Sick Of Beige 50x50 with custom laser cutting from Ponoko (dimensions later exported from Eagle as PDF and then post processed in Inkscape and exported as SVG). PCB is from OshPark and stencil is from OshStencils (5 mil). The board was reflowed with hot air station (notice the cooked trimpot at the lower right corner).The project is open sourced herehttps://github.com/zapta/power-monitors/tree/master/pmon_unoand the schematic is herehttps://github.com/zapta/power-monitors/blob/master/pmon_uno/eagle/pmon_uno.pdf?raw=true

author: IanJ
author_rank: Unknown
timestamp: May 04, 2014, 05:05:18 pm
content: Hi all,Just finished building my own bench PSU.Just repaired a P6046 PSU (bad caps and shattered case so repackaged it).And am now currently repairing the P6046 probe (blown input fets).The P6046 repair is just filling time whilst I contemplate my next meaty project.......which is likely to be an ethernet adaptor for a Sinclair QL.

author: BravoV
author_rank: Super Contributor
timestamp: May 04, 2014, 06:45:34 pm
content: Quote from: IanJ on May 04, 2014, 05:05:18 pmJust watched your video there, nothing serious, don't throw away that old enclosure yet, that tiny 110 V face plate that is screwed by 2 screws actually has a two sides label, the other side is printed with 230 V on it.

author: tom66
author_rank: Super Contributor
timestamp: May 17, 2014, 09:36:06 am
content: Tour de France countdown clock for Yorkshire's Grand Depart. I designed the electronics, and another student (other Tom) assembled it and fix the things that were wrong (there were quite a few - it's my first project of fairly signficant size, though all in all, the errors were primarily mechanical clearance problems; IDC ribbon cables and putting relays too close to each other, etc.)It was stressful, all had to work in time for the 50 day countdown, but it worked fine in the end. (In total we had about 6 weeks from design to production and installation, but we were only able to install the electronics in the clock on Tuesday, for a Friday show.)Project requirements: 50 x LED channels (5W each), PWM controlled. 12 x motor outputs all independent with speed control. One class D audio amplifier.The MCU is a TM4C123GH6PM (TI Tiva C series) which is a really nice processor. I had no major issues getting all of the peripherals to work. A Raspberry Pi handles the audio system, as trying to get that working on a Tiva was seen as ambitious for a short term project.The idea was for the electronics to be visible, so they had to look "attractive" - tall electrolytics, multi-coloured wire, many LEDs, a VFD for status etc.Tweaks to the show were being made just 10 minutes before it went live... but it all worked in the end!Featured on BBC Look North:https://www.youtube.com/watch?v=7YjmuyXtauE&feature=youtu.be

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: May 17, 2014, 10:08:29 am
content: Quote from: IanJ on May 04, 2014, 05:05:18 pmHey. Very nice looking PSU. Can we have more info?

author: staxquad
author_rank: Frequent Contributor
timestamp: May 17, 2014, 04:02:17 pm
content: Quote from: Ed.Kloonk on May 17, 2014, 10:08:29 amhttps://www.youtube.com/user/IanScottJohnston/search?query=home+built+bench+power

author: TiN
author_rank: Super Contributor
timestamp: May 21, 2014, 04:38:06 pm
content: Cool wheelMeanwile, I just fixed smart battery (copy of nikon's EN-EL4)

author: rexxar
author_rank: Frequent Contributor
timestamp: May 24, 2014, 01:24:41 am
content: I just got the Rev C boards in for my first project! I'm calling it the IoDriver (Io as in the moon, not I/O), and it's really just an LED driver.This is designed to go into model light sabers, the idea is to use an RGBW LED to create different colors in the blade, with multiple programmable patterns. There's already some commercial products for this, but they cost $150-$200! I'm selling these for about $60, so I've already got some people from my brother's lightsaber group that want to buy them as soon as I'm doneIt's been a very interesting challenge to see how small and how cheap I can get this thing. I've not had any sort of instruction on PCB design, so it's kind of a mess, but I'm still proud of it. Once I finish everything, I'm gonna publish it as open source. I had a few square mm of extra space, so I took Dave's advice and added an animal logoI don't like how cramped it looks with the reference designators everywhere, so I think once I'm done with prototyping (soon, hopefully!) I'll just leave them off.

author: Tinkerer
author_rank: Frequent Contributor
timestamp: May 24, 2014, 01:40:38 am
content: QuoteI think an important question here is why would you put a rabbit instead of Yoda's head? Although, is a general image of Yoda's head trademarked or the like?

author: GreyWoolfe
author_rank: Unknown
timestamp: May 26, 2014, 01:49:44 pm
content: Quote from: Tinkerer on May 24, 2014, 01:40:38 amBecause the penguin was already taken?

author: idpromnut
author_rank: Unknown
timestamp: June 12, 2014, 12:35:43 pm
content: Picking up and trying to get a version of a USB-powered lab supply (based on Dave's white-board work) built. Oh, and gratuitous shots of multi-meters + uCurrent!

author: N TYPE
author_rank: Regular Contributor
timestamp: June 12, 2014, 01:19:40 pm
content: I just hacked my cars Intermittent window wiper module to add adjustable delay.I took the adjustable wiper stalk from a junk car which is basically a 30k ohm potentiometer.The existing circuit just used a 56k resistor charging a 47uf cap to set the RC delay but I changed the cap value to 66uf (two 33uf in parallel) and a 6kohm resistor in series with the 30kohm pot to give me the desired interval. Works a treat

author: SeanB
author_rank: Super Contributor
timestamp: June 12, 2014, 05:48:39 pm
content: The difference between the standard and the adjustable one is often only a small wire bridge inside the stalk with the right resistor to give the delay as a permanent part of the stalk. To upgrade to the adjustable all you need to do is change the stalk with the adjustable one.Older Fords all you needed to do was use the adjustable one, and add the wire to the loom along with the relay. There the volume was high enough to justify keeping 2 looms for the vehicles and the 2 relay part numbers.

author: jlmoon
author_rank: Unknown
timestamp: June 12, 2014, 09:47:12 pm
content: Replacing by hand ribbon connector CN6 on this dsp board for a Kenwood transceiver. Really tight spacing between pins, requires .015 solder and .015 tip and a really steady hand and microscope.No re-flow on this one!

author: rob77
author_rank: Super Contributor
timestamp: June 12, 2014, 09:58:04 pm
content: Quote from: jlmoon on June 12, 2014, 09:47:12 pmi would definitely reflow that one with hot air and small nozzle using a 63/37 paste (lower temp than leadfree).

author: jlmoon
author_rank: Unknown
timestamp: June 13, 2014, 05:59:57 am
content: @rob77,I ordered a new HAP1 (weller hot air pencil with a 1.1mm nozzle) for my rework station and will attempt a re-flow process. Only potential problem I could run into is getting that plastic connector too hot and melting it. The 63/37 combo solder might just do the trick. Thanks for the suggestion.JLM

author: ampdoctor
author_rank: Frequent Contributor
timestamp: June 13, 2014, 08:37:47 pm
content: @jlmoonHave you tried to drag solder that component? A small hoof or chisel tip iron works surprisingly well on fine pitch components like this. Flood the area with flux, work quickly, and let the solder mask do its job.

author: rob77
author_rank: Super Contributor
timestamp: June 14, 2014, 07:15:02 am
content: Quote from: jlmoon on June 13, 2014, 05:59:57 ama strip of kapton tape over the plastic or cover it with alufoil - that will prevent the plastic go absorb too much heat. but i think those connectors are designed for reflow.another option would be to reflow it with Sn42Bi58 solder paste using low temp air (~140-150 celsius) - but ONLY if there original solder was unleaded and ONLY if there is no mechanical stress on that connector (bismuth solder is brittle ) even a tiny amount of lead will do nasty things with the Sn42Bi58 ( areas with melt point of 95 celsius will be created - resulting in unreliable joints).

author: marshallh
author_rank: Unknown
timestamp: August 31, 2014, 12:15:48 am
content: specialized HDMI upscaler

author: marshallh
author_rank: Unknown
timestamp: October 19, 2014, 02:01:06 am
content: Next rev

author: IconicPCB
author_rank: Super Contributor
timestamp: October 19, 2014, 02:52:15 am
content: Building a stepper motor to Galvo movement interface to be driven by LinuxCNC.The interface will synthesize Laser diode drive signals from stepper signal such that the laser plots the content of G code file onto photo sensitive material.Plotting area 600mm x 600mm with a 16 bit resolution.Hope to use some of the scaling and calibration capabilities of LinuxCNC to eliminate corrective optics.

author: graynomad
author_rank: Regular Contributor
timestamp: October 20, 2014, 01:04:15 am
content: A Mega2560-based board with many goodies including 512k of external SRAM.I had boards made and full PCBA of all SMD parts, but it took so long I lost interest in the project. Then when I finally got the boards there was a major stuff up (don't ask, my fault) so I decided to move on to something new and mount these on my wall.Anyway 8-bit AVRs are so last decade.

author: poorchava
author_rank: Super Contributor
timestamp: October 20, 2014, 06:40:04 am
content: Trying to fix a CEAG SP15003 2x 12V 4A military power supply. Built around 1980, produces nasty high-pitched noise and awful smell, but still works up to spec (?). The thing is built like a tank, enclosure is made of 2mm sheet metal (not speel though, I think some duralminium alloy)Anyway, pictures:

author: Jim95
author_rank: Contributor
timestamp: October 20, 2014, 10:00:20 pm
content: A digital clock using bcd counters and AND gates.The 7 segment displays are on their way with the driver chips.I accidentally order a 32.768Mhz clock instead of the 32.768Khz so I've ordered one of those too :sUsing an arduino as the clock for now though, got the seconds working correctly this morning.I'm planning on getting a PCB made for this, any recommendations for one-off pcb manufacture in the UK?IMG_0012bycoxjames95, on FlickrAlso been playing around with this as part of a uni module, haven't done much apart from using it to solve maths problems and understanding the debugger. A bit tougher than arduino for sure.IMG_0013bycoxjames95, on Flickr

author: jc101
author_rank: Frequent Contributor
timestamp: October 21, 2014, 10:07:56 am
content: Quote from: Jim95 on October 20, 2014, 10:00:20 pmGivehttp://www.eurocircuits.coma look, their Proto pool might be suitable. Oddly, it can be much cheaper to order 3 or 5 of something than 1.

author: RR
author_rank: Contributor
timestamp: October 21, 2014, 01:17:32 pm
content: Quote from: marshallh on October 19, 2014, 02:01:06 amNice board! Whats the point of the small hole next to mounting holes? and where is your power input just from FFC?

author: SeanB
author_rank: Super Contributor
timestamp: October 21, 2014, 05:01:58 pm
content: Quote from: poorchava on October 20, 2014, 06:40:04 amChange the axial capacitors all over, they are shot.......... Just remember to tie them down again, especially if there is any vibration. Keep the knot tight afterwards with a drop of superglue.Aah, the joys of military electronics, where cost was not one of the major considerations, but servicing was still there as a major thought. Lasting forever was also much desired, and surviving troops as well.

author: rexxar
author_rank: Frequent Contributor
timestamp: October 25, 2014, 08:55:00 pm
content: Quote from: marshallh on October 25, 2014, 05:10:01 amWhat's that? Some sort of SD card emulator?

author: PointyOintment
author_rank: Frequent Contributor
timestamp: October 26, 2014, 07:12:18 am
content: Quote from: rexxar on October 25, 2014, 08:55:00 pmHere's what I see on the board, apart from the obvious SD plug:a name, "SDX-001"—not very informative,a microSD socket (at the top left),several solder jumpers labeled "bridge SD" (center),two chips that look like flash or RAM—though I'm not sure about the blue rectangle under one of them (top),a chip that looks like an FPGA (middle),a chip that could be memory to store the FPGA's configuration (?) (bottom right),a USB micro-B connector and "USB PWR" text (bottom left),a chip connected to USB, possibly a USB-to-serial converter or microcontroller (which could also be to manage the FPGA) (between the previous two parts),a 10-pin header, possibly for JTAG or programming the FPGA (middle left).Thoughts:The USB isn't just for power, as indicated by the text "3V3 source / A: SD_PWR / B: USB_PWR / only jump either" (meaning this device can be powered by USB or by the SD slot it's plugged into, but not both). That means it's meant to be connected to a computer during (at least some of) usage.The "bridge SD" solder jumpers are presumably to connect the two SD interfaces directly rather than going through the chip(s).Those two chips at the top probably aren't used to store data that it presents to the SD host, because there's a microSD socket that would make more sense for that. They're more likely sample memory, IMO.My guess: SDIO protocol analyzer(/injector).

author: marshallh
author_rank: Unknown
timestamp: October 26, 2014, 08:28:47 pm
content: Not far off the mark, 1gbit nor/nand/lpddr + ulpi phy

author: Artlav
author_rank: Frequent Contributor
timestamp: October 28, 2014, 02:45:35 pm
content: Sorting the boxes of random stuff can produce rather unexpected items.Like an oscilloscope CRT tube.And what's a better use for one than to make a clock out of it?I wonder if making a neat package for it would be harder than making it work...

author: TonyStewart
author_rank: Contributor
timestamp: October 28, 2014, 04:23:04 pm
content: A repetitive partial discharge with sub nanosecond 10V into 50 Ohm Ac coupled from 5MVA Distribution Transformer. 44kV-1.4kVRoot Cause is sloppy MFG process controls for magnetic dust creation.The magnetic particles shed from edges of CRGOS on laminated cores along roller track Assy line. Later articles disperse and get energized in mineral coolant oil and create excess Hydrogen under high field strength in the field in less than 1yr.Epidemic problem only detected by Dissolved Gas Analysis.Risk to explosion if not monitored for H2 by customer.

author: rob77
author_rank: Super Contributor
timestamp: October 28, 2014, 05:44:56 pm
content: Quote from: Artlav on October 28, 2014, 02:45:35 pmgreat idea ! i like iti would suggest to make a retro-style wooden case for it, or perhaps a bit of steam-punk decorations

author: andtfoot
author_rank: Unknown
timestamp: October 27, 2015, 04:43:22 pm
content: A lot of the stuff I find myself doing at the moment is just little odd jobs here and there; not exactly worthy of a separate thread. Thought I'd dig this one up instead of starting a new one...Recently, I had the HDMI port on a Dell laptop break... again. The first laptop had the pins separate from the middle plastic section after a dozen or so uses. The second had the middle section fracture in a similar time-frame like so:Dell warranty is useless in this regard, and they wanted $900 or so to repair it, so I thought I'd give it a go (on the 2nd laptop). The connector is some weirdo mid-plane through-hole jobbie that I couldn't find anywhere, so I ended up getting a spare motherboard from the UK and did a transplant.A hot air rework gun and a bit of hair pulling later, and I now have one working (if slightly melted) HDMI port again.What I just finished up now is rebuilding the guts of a guitar distortion pedal I made about 10 years ago. It was a bit noisy (not in the good way), and I figured the rat's nest within could use a cleanup. I also added indicator lights for the bypass and boost switches. This is partway through:The finished 'product' (yes, the labelling is the epitome of fine calligraphy). Testing to happen when it's not 3:30am...

author: AF6LJ
author_rank: Unknown
timestamp: October 28, 2015, 03:40:29 am
content: Good projects here, I'll post something in the next day or two.Couple of projects going on.Six meter transceiver, and my IFR service monitor. (AGAIN)

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 28, 2015, 06:15:55 am
content: Most recent project my best friend and I finished - open hardware HD audio DAC:https://github.com/NiHaoMike/OpenDAC-HDOne I'm currently working on is a linear actuator driver for a gaming force feedback device. No pictures yet since I'm still working out the hardware architecture.