hybridfree/eevblog-posts huggingface dataset:
Fine gauge wire - Page 1
Forum section: electronics / projects

author: MacAttak
author_rank: Unknown
timestamp: January 16, 2014, 07:19:38 am
content: I'm trying to find a specific type of wire and having zero luck. I'm sure that I probably just don't know what keyword to search for.I'm looking for stranded wire - I'm guessing it is 28 or 30 gauge - the same kind that is always used for the wiring connector on small brushless fans, 9volt battery clips, etc. It is extremely flexible and doesn't easily fail due to repeated flexing. Dual-conductor would be ideal (usually see it as a red and black pair). I assume this stuff is also cheap because you see it all over inside of inexpensive electronics.Can anyone help me out by at least enlightening me to the proper name of this type of wire? I'm looking to buy a spool or two.

author: Jon86
author_rank: Frequent Contributor
timestamp: January 16, 2014, 07:21:41 am
content: I've been looking for some of this too actually. Seems like the best stuff to do low current power wiring with.

author: cellularmitosis
author_rank: Unknown
timestamp: January 16, 2014, 08:25:28 am
content: Search ebay for 24 awg silicone wire. The keyword "silicone" is what brings up the really flexible stuff, which means lots of super fine strands.I ordered 50 feet of red and black. It is super duper flexible.http://m.ebay.com/itm?itemId=161100070755The 18 awg stuff from Pomona is also excellent.

author: andtfoot
author_rank: Unknown
timestamp: January 16, 2014, 11:28:02 am
content: I know what you are talking about, but don't the answer sorry.As an alternative, how about splitting up ribbon cable into pairs of wires?

author: neslekkim
author_rank: Super Contributor
timestamp: January 16, 2014, 12:43:57 pm
content: Quote from: cellularmitosis on January 16, 2014, 08:25:28 amDoes this have some markings on the cable?, what type it is?This seller doesnt ship outside US, and when I find other cables that are similar, they do not say how many strands there are inside, I see that this one have 40 strands of 0.08 size, which makes it very flexible, but other silicone 24awg cables are marked 3239 or something like that, so I wonder if that says anything about strands etc.But then again, buying this from china will probably give me bad cable..
fine pitch LED strips? - Page 1
Forum section: electronics / projects

author: djacobow
author_rank: Super Contributor
timestamp: October 11, 2014, 05:33:49 pm
content: A friend of mine is building a museum and asked me if I could help him with an exhibit. There is a slightly translucent topo map (actually topological not just with topo lines) about 2m x 2m. He would like to be able to illuminate different trails from below, when a visitor selects them on a tablet associated with the exhibit.His original idea was to drill the map with lots of LEDs wired for each trail, but I'm trying to think of more elegant and, honestly, easier ways to do this.Control and driving I have dialed. I'll probably use bluetooth as the communications link with the tablet and just use FETs to switch the LEDs. But I'm trying to think of the best way to actually do the illumination.The kinds of LED strips one finds on e-bay seem promising, but they have a few issues. For one, the glue is on the wrong side for this app. The other is that the LEDs are relatively few and far between to show what might be a trail just a few inches long at this scale.If anybody has ideas, I'd be appreciative!Regards,Dave J

author: SeanB
author_rank: Super Contributor
timestamp: October 11, 2014, 06:02:33 pm
content: Can you drill small holes and use a fibre optic as light, collecting the tails together for each trail into a bundle illuminated with a single high power LED in a machined holder that will heatsink it. That way you have small dots to indicate a trail, yet the ability to have them very close together for different trails.Otherwise a LED lit LCD projector to display a thin line for each trail on the back of the translucent map sheet. that could even be animated or display a video in a small flat spot easily.

author: ajb
author_rank: Super Contributor
timestamp: October 12, 2014, 02:50:05 am
content: Or maybe use side glow fiber and just lay a single fiber (or bundle of fibers) along the trails. EL wire could work if the ambient lighting isn't too bright.

author: djacobow
author_rank: Super Contributor
timestamp: October 12, 2014, 03:35:31 am
content: Side glow fiber -- now that's a thing I didn't even know existed. Will definitely look at that.I had thought of EL. I think it will be too bright for it, but I should be sure.The projector idea sounds like it would be uber flexible and cool, but pricey and maybe not too compatible with a well-lit room.Thanks, guys!
Finger/Miniature Joystick (that don't cost $150+) - Page 1
Forum section: electronics / projects

author: permal
author_rank: Regular Contributor
timestamp: August 05, 2025, 08:20:21 am
content: Hi,I've been thinking of putting together a Bluetooth controller for my tablet, to be mounted on a motorcycle, something similar to Thork's controller, seehttps://api.advhub.net/storage/uploads/2025/05/09/dmd-remote-2-02_uid_681db82a4ca9e.jpgFor this I need a 4-way/two axis finger/miniature joystick, much like the one in the image above, but the ones I find are priced at $150+ (such ashttps://www.mouser.se/c/?marcom=154925933) which I find excessively expensive.The complicating factor is that they need to be IP67 to withstand rain and dust.Do you have any suggestions on where to source (just a few) of such parts at a reasonable price?Thanks!

author: Terry Bites
author_rank: Super Contributor
timestamp: August 05, 2025, 05:48:21 pm
content: Use a cheap joystick and make it IP67 by chosing the appropriate boot.https://www.google.com/search?q=+joystick+boots+&client=firefox-b-d&sca_esv=d5e847b1dc31b2cb&udm=2&biw=1642&bih=1001&ei=SEOSaP3GCuC-hbIP2pj88A4&ved=0ahUKEwj9ipDZnPSOAxVgX0EAHVoMH-4Q4dUDCBE&uact=5&oq=+joystick+boots+&gs_lp=EgNpbWciECBqb3lzdGljayBib290cyAyBBAAGB5I0zVQtAVYmzJwAngAkAEAmAF4oAGMBqoBAzcuMrgBA8gBAPgBAZgCB6ACugTCAgoQABiABBhDGIoFwgIGEAAYBxgewgIFEAAYgASYAwCIBgGSBwM1LjKgB4EasgcDNC4yuAe2BMIHBTAuMS42yAcX&sclient=img
Just finished a board to play with crystal oscillators - Page 1
Forum section: electronics / projects

author: hamster_nz
author_rank: Super Contributor
timestamp: November 01, 2018, 09:40:03 am
content: I've just sent off a board to play around with crystal oscillators and tuning them, loosely based on Figure 6 of this app-notehttps://www.analog.com/media/en/technical-documentation/application-notes/an12fa.pdfThe cutouts are so I can make a small insulated enclosure for the center section out of EPP or PS foam, and use the 1/4W resistors to heat it up.It has a mishmash of SMD and THP is because I'm using mostly junk-box parts.Anyhow, just thought I'ld share- is anybody else out there working on any experiments, just for the heck of it?

author: iMo
author_rank: Super Contributor
timestamp: November 01, 2018, 10:05:03 am
content: It depends what is your goal..You will not get something even close to the cheapest tcxo's performance with that design, imho. The performance will be something like the cheapo canned oscillators from old motherboards.7805 is noisy and not stable enough, you need a special oscillator circuit and crystal to get stability and noise, the LM319 is rather slow, heating with those resistors has no sense unless you control the temperature..

author: hamster_nz
author_rank: Super Contributor
timestamp: November 01, 2018, 10:16:26 am
content: Quote from: imo on November 01, 2018, 10:05:03 amIt's just for experimenting/learning, rather than watching TVThe temperature will be monitored & controlled by a small micro, or more likely a spare Raspberry Pi Zero.

author: iMo
author_rank: Super Contributor
timestamp: November 01, 2018, 10:20:22 am
content: Quote from: hamster_nz on November 01, 2018, 10:16:26 amYou will experiment, then you will spend $25 for a double ovenized ocxo from ebay, and then you will again sit and watch TV

author: hamster_nz
author_rank: Super Contributor
timestamp: November 01, 2018, 10:32:24 am
content: Quote from: imo on November 01, 2018, 10:20:22 amSounds like all of hobby electronics :-)

author: iMo
author_rank: Super Contributor
timestamp: November 01, 2018, 11:02:12 am
content: Indeed, almost all of us went through the same exercise you plan.. Spent months and $$ and finally bought a few ocxos off ebay.PS: not to discourage you from your experiments - the electronics itself is doable (low noise, high stability, low tempco design), the mechanics is doable (box, heater, etc).What is difficult is to get the Crystals - the famous vendors use special cut crystals (usually their know-how), with pretty specific params, especially with aging, temperature vs. stability, oscillation modes, phase noise, power levels, eq. LCR params, packaging, etc. Also, you must be able to measure the output with required precision/resolution..
Finished ATTiny2313A Necklace - Page 1
Forum section: electronics / projects

author: Stonent
author_rank: Super Contributor
timestamp: December 27, 2013, 09:09:18 am
content: After this video I went to Harbor Freight and got a 4 pack of CR2032 Batteries for $1.99 and used my Tayda $0.10 coin cell holder.So total parts:1 x ATTiny 2313A (Free Atmel Sample)1 x LTP-757 5x7 LED Matrix ($1.00 from Jameco)2 x 2 inch pieces of wire (practically free)1 x CR2032 Coin Cell ($ 0.50 at Harbor Freight)1 x CR2032 Coin Cell Holder ($0.10 from Tayda Electronics)1 x DIP socket (Used inside the necklace so I can remove the chip and put it back in the breadboard for programming)1 x Snowman shaped candy container (Free from Christmas candy)3 feet of red ribbon (Free from Mom)Also Needed:Atmel / AVR Studio (Free)Arduino or AVR Programmer (Anywhere from $5 to $30)BreadboardJumper WireSoldering IronSolderXacto KnifeI'll post my code later, it's on a different computer, but basically what Bruce Hall at W8BH.NET has for this with my own added Christmas symbols.Fuses are set to 4MHz, 65ms delay, Div8 off, SPI enabled.
Finished: current limiting breaker - Page 1
Forum section: electronics / projects

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 13, 2017, 09:05:11 am
content: Whassit do? No idea, it's bedtime, I'll let you savor the mystery until then...Tim

author: BrianHG
author_rank: Super Contributor
timestamp: December 13, 2017, 06:22:10 pm
content: It makes you dinner.

author: Nusa
author_rank: Super Contributor
timestamp: December 13, 2017, 06:25:23 pm
content: Clearly it causes uncontrollable sleepiness.

author: rx8pilot
author_rank: Super Contributor
timestamp: December 13, 2017, 06:28:16 pm
content: Does it have 7 transistors?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 13, 2017, 08:31:51 pm
content: Quote from: rx8pilot on December 13, 2017, 06:28:16 pmUnfortunately I wasn't able to do it in 7 transistors, though arguably, the core analog part is about 7 transistors, but there's about 14 transistors total, except it's 15, plus a logic gate. Not even a good rationalization exists!Unfortunately it does not make dinner, indeed it prevents cooking things.The function is a 30V, 20A current limiting breaker. It is bidirectional -- doesn't matter which way around you hook it up, or if you have a load that's charging or discharging. It is also efficient, or, it can be: it has a buck converter action, so if you connect the ground return to supply negative, the excess power is recycled rather than dissipated. Breaker action clears in 150ms: more than long enough to start the heaviest capacitive loads.I built it specifically for my laboratory 24VDC supply (some lead acid batteries, a fusebox, charger and whatever loads I wire in), so I'm not constantly burning fuses or sparking connections as I work with motors, controllers, converters, inverters and so on.It is also a switch. Pushbuttons turn it on and off, or there are pins on the header to trigger them with optoisolators. This allows everything from automotive to industrial load switching, with safe starting and limiting.Tim

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 14, 2017, 07:00:06 am
content: Here's the front panel graphics. Had to wait until today to draw it.Tim

author: oldway
author_rank: Super Contributor
timestamp: December 14, 2017, 08:18:16 pm
content: Congratulations,Is this a project you have done for yourself, for one of yours customers, or do you intend to sell it on the market ?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 14, 2017, 08:19:42 pm
content: Quite marketable, yes. Looking for interest, and suggested market places.Tim
Finished custom doorbell project - Page 1
Forum section: electronics / projects

author: MadModder
author_rank: Regular Contributor
timestamp: December 04, 2016, 05:45:48 pm
content: Ever since I found one of those old telephones with two bells inside, I wanted to build a doorbell out of it. Not the whole phone of course, just the bell/ringer assembly.One day several (as in eight) years later (february 2016) I decided to do something about it, and cobbled something together on the breadboard:Then I transfered that to the computer, my first Altium schematic!Top left is the power part. J1b is for the button outside.Next to the right are the decoupling caps, and then the unused logic.Bottom left is the counter, making an irregular ringing pattern. DING and DONG are the outputs going to the H-bridge.Next box is the output stage, an H-bridge. Because the ringer must be driven with AC. The clapper is going in either direction depending on the polarity.I wanted a 3D-view of it so I spent quite some time to find 3D-files for everything. Some good, some not so good. I could not find a proper one at all for the trimmer pot. I'll design one myself, later, when I know how to do.After some work with the old PCB-making stuff (Very old. The chemicals were barely usable...), and a soldering session I had this:The next day I spent in the garage, making a housing for the build. I wish I had my CNC router done by now... But it went well with only handheld powertools.Testfitting the ringer in the oak housing:The day after that I polished the bells, oiled the housing, mounted the boards, and screwed it up on the wall:It's still working almost a year later.Someone always asks for the copper layout, so here it is. Single layer.I swapped the colors for top and bottom layer, beacuse I'm used to red bottom layer from using Orcad for a long time.Updated the schematic.BTW, the voltage for the door bell comes from an 8V DIN-mounted transformer in the breaker box/cabinet. It has a very high idle voltage, around 15VAC. After doubling and smoothing I've got slightly more than 40VDC.
Finished DIY amp rework/upgrade :) - Page 1
Forum section: electronics / projects

author: Benedict
author_rank: Regular Contributor
timestamp: September 21, 2015, 04:49:53 pm
content: http://imgur.com/a/o4XRaNot much to say, but it's working nicely

author: EK701
author_rank: Contributor
timestamp: September 21, 2015, 05:13:48 pm
content: Very nice! Are the details on the electronics available?

author: Benedict
author_rank: Regular Contributor
timestamp: September 21, 2015, 05:40:57 pm
content: Sure, it's based on the dual lm3875 amp, just a couple extra resistors and capacitors inside, I just sealed it inside and would have to tear it all apart to draw a schematic for this particular one, but the chip itself is quite great and I'm sure there are many schematics for it freely available - as said I didn't really make this amp, just improved it. The guy who did is a family friend, I could ask him for this exact schematic if you want to, but I'm not really sure that's needed really, you'll probably find better online anyway. Good luck, it's a really simple design, but gives a really great linear performance (check the schematic for the amp, it's really good), and is really cheap too.You'll need to build a suitable positive + neg psu for it, and if you decide to tackle it, I suggest you read on this :http://sound.westhost.com/earthing.htmhttp://www.diyaudio.com/forums/diyaudio-com-articles/163575-audio-component-grounding-interconnection.htmlhttp://sound.westhost.com/articles/electrocution.htmhttp://sound.westhost.com/articles/fusing.htmhttp://sound.westhost.com/power-supplies.htmThe thing is, tube amps distort the signal a lot, and sound different. While that may be considered "good", it's always a good idea to have a linear semiconductor based amp, with next to no distortion, and cheap.
Finished: LM723 based Bench power supply  - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: January 23, 2017, 09:59:10 am
content: HiI just want to share weekend projectLM723 based power supply in wooden boxIt use two small off the shelf smps instead of classic linear transformersimple design with minimum component count, added diodes to set minimal voltage to zerovoltage meters are based at atmega, just because I want to not forget programming themcurrent meters are from old stocks as is most components like led displays, passives and heat sink (Intel .)
Fire Warden Phone Loop System error detection. - Page 1
Forum section: electronics / projects

author: DeanA
author_rank: Regular Contributor
timestamp: May 19, 2022, 01:14:13 am
content: I am working on an interface unit for a fire warden phone loop system which looks something like this:" alt="" class="bbc_img" />There can be many warden phones in the loop, only 4 units shown above.There is a requirement for each interface unit to detect any short or open circuit errors in the loop.I think I have a circuit solution for short circuit detection worked out but am a bit stumped for a solution to open circuit detection so am looking for any suggestions.For the short circuit isolation and detection I have tested this circuit which seems to be doing the job for the DC power lines." alt="" class="bbc_img" />If either the +input power or +output power is shorted to minus in or minus out D3 or D4 will rob Q2 of base current and turn off the mosfets Q1A & B.For the audio line short circuit detection to plus or minus, my idea is to bias it at half rail and use a window detector to make sure it is not above or below certain level.Any recommendations for open circuit detection? I’m guessing this problem has been solved for previous safety systems so don’t want to re-invent the wheel.Thanks in advance for any advice.
Fire/flame detection cheap sensor finding - Page 1
Forum section: electronics / projects

author: Dhanushka
author_rank: Regular Contributor
timestamp: July 01, 2021, 04:28:34 pm
content: Hi,Could you please suggest me sensors which can be used to detect fire/flame from some distance?The IR dual pin PIN phototransistor based hobbyist flame sensor module did not worked well for outdoor due to sunlight contains IR. The response of these for sunlight was the problem.It is better that if these sensors and cheap and available in ebay/aliexpress.Or, if can you suggest a alternative solution for a cheap fire/flame detection, I highly appreciate.Thanks

author: GhostDog
author_rank: Newbie
timestamp: July 31, 2021, 02:49:56 am
content: Long range fire detection probably isn't viable on a low budget, unless you want to mess with vision detection AI stuff.What I'd recommend is getting a Basalt Cable cover (can handle >650c) and seeing if you can get a fireproof thermistor.Another option might be to look into hacking apart a non-contact thermometer and trying to get a reading off the electronics in those (not exactly affordable IMO but you might find a cheap one).

author: RJSV
author_rank: Super Contributor
timestamp: August 01, 2021, 11:27:21 pm
content: Check out Systron Donner, in Concord, CA.Might be higher cost, than some hobby type parts.They make and sell FIRE and overheat sensors and the systems associated. Often 28 VDC for aircraft systems.The company has sold two types of mechanical / gas pressure actuated sensors, both for 'Fire' (extreme heat) and also for 'gross overheat', a general condition inside an engine cowling etc. (Circa 1980).Using Google, I tried to find the optical sensor products, inventor Clark Bright assigned patent to Systron Donner. But pretty sure they were using interrupted or 'chopped' analog from the low output level sensor. That way, it's an AC signal; easier to process and amplify.Try not to violate any patents or copyrighted stuff (I did used to work there!)I think maybe spend some time, Google Patents, to check out (any) other similar flame sensing patents.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 02, 2021, 10:42:06 am
content: I recall one approach uses thermopile sensors, watching for a noisy signal in the 1-10Hz range characteristic of flame flicker.Tim

author: LaserSteve
author_rank: Super Contributor
timestamp: August 03, 2021, 02:51:42 am
content: Honeywell and Hamamatsu make solar blindUv fire sensors.Steve

author: Miyuki
author_rank: Frequent Contributor
timestamp: August 03, 2021, 04:30:34 am
content: Depends on the price, they are not the cheapest but high range it thermal sensors are designed for fire detectionLike MLX90614 or more resolution MLX90621They can measure over 300 °C to mitigate false positivityFor detection of solid fuel fires and most of the liquid fuelsWon't detect like natural gas unless it heats something
firefly zero: new handhend console - Page 1
Forum section: electronics / projects

author: exe
author_rank: Unknown
timestamp: January 26, 2025, 11:23:12 am
content: Ladies and gentlemen,Let me present you our handheld console, an early prototype. I'm a bit ashamed how plain it looks currently, but hey, it's an alpha.A short demo you can see here:https://gram.social/p/firefly/788373396905416245. Our website:https://fireflyzero.com/.Inside you'll find an esp32-s3 that runs webassembly "cartridges". It serves the display and sdcard. There is a second esp32-s3 that does the rest of IO, including networking. There are many functions that are not working yet: battery management, sound, power button, networking. I hope on the second prototype I'll fix all of that.This is not an emulator, we are looking at creating new and unique content. Although, as you may see, the snake game is not exactly new gameplay). Currently we mostly simple demos in our game catalog:https://catalog.fireflyzero.com/.So, what's unique about it? Well, I'm glad you asked). From hardware prospective, we want these features that are not easy to find in handheld consoles:- same-room multiplayer- ambient light- touchpad inputI'll quickly mention how multiplayer works. For a game developer, the peer device is seen as a joystick input. As long as game is running deterministically (and we make sure they do), all connected devices are perfectly in sync. The underlying implementation is esp-now.I'll skip other details for now. If you are interested, please ask questions.PS we will be presenting our device at FOSDEM 2025 in Belgium next week. If you pass by, say hello to me).
Firewire device loses connection when powering off other devices. - Page 1
Forum section: electronics / projects

author: mkiijam
author_rank: Regular Contributor
timestamp: November 25, 2022, 05:19:43 pm
content: I use an old Digidesign 002 to test various pieces of audio gear. It uses firewire to connect to a windows computer. Randomly, when power off the device under test, the 002 will lose its connection to the computer. This is immediately evident as the software that I use, Protools 8LE, stops responding.At this point, the assumption is there is some sort of spike on the power line that gets into the 002 through the IEC AC connector.I know this is a very specific failure mode, but I'm hopeful that someone can shed some light on how Firewire may be so finicky, and perhaps a way to filter the issue out or something?**NOTE** It is happening a ton right now. I am using a home grown PSU to operate an audio device. It consists of a large step down power transformer and two LM317 type regulators to make a +/- 18v supply. The power supply on the 002 is switch mode.

author: magic
author_rank: Super Contributor
timestamp: November 27, 2022, 10:58:08 am
content: Okay, but what exactly happens? What are the other devices, does it matter if they are connected to the FW device, is it simply going bonkers when you plug/unplug anything to mains in the same room?

author: mkiijam
author_rank: Regular Contributor
timestamp: November 27, 2022, 06:05:04 pm
content: SETUP:Device A = Digidesign 002 ( SMPS) IEC Ground/ChassisDevice B = Home grown PSU (TRX / LM317, LM337, Filter caps, bridge rectifier etc.) IEC Ground/ChassisDevice C = some audio device. IEC Ground/ChassisDevice D = Windows computer IEC Ground/ChassisA+C connected with XLR cables.A+D connected with Firewire cable.Toggle the switch on the HomeGrown PSU and blinko, firewire drops... randomly.I have not specifically tested if it matters if the device is connected to the 002/Firewire device yet, but many other things get turned off )soldering stations, lights etc... and they do not seem to trigger they event to the best of my knowledge.
Firmware for Wilo variable frequency boost pump (Renesas H8/36077 MCU) - Page 1
Forum section: electronics / projects

author: strnad.cv
author_rank: Newbie
timestamp: February 16, 2025, 04:18:59 pm
content: Hi !I would like to share my project of reverse-engineering and replacing the firmware of the variable frequency "boost" water pump that I'm using for my tap water supply. The exact type of this pump is Wilo EMHIL 505 EM. It's not being sold anymore although a standalone variable frequency drive from Wilo called "ElectronicControl MT6" which may possibly be hardware-identical is still available.https://github.com/solar-pwr/wilo-vfdI was not happy with the original firmware as it kept switching the pump on at regular intervals (like 5 or 10 minutes) even when there was no water flow and the pressure was still well above the setpoint. Also the regulation was often self-oscillating so significantly that the pressure dropped almost to zero.My firmware doesn't suffer these problems. It has much more parameters that can be configured, like pressures and frequencies for the regulation, V/f ratio of the VFD, fault detection thresholds and intervals. Also the status values that are shown on the display can be read remotely through the serial port using Modbus protocol.It's important to mention that I was not able to retrieve the original firmware from the chip, so I had to start writing from scratch and had no way of flashing back the original firmware. In "boot mode" the chip always erases the flash as soon as it starts communication with the flash tool. Later I realized that it might be actually possible to read the flash in another mode called "Programming mode", with "TEST" pin shorted to GND, where the chip should expose the parallel interface of the flash memory on its pins. But I haven't tried that.I don't really think that someone else there actually still uses this pump and decides to test my firmwareHowever, it might be useful as an example of code for H8 MCU, or example of handling the VFD waveforms in an interrupt.

author: moffy
author_rank: Super Contributor
timestamp: February 16, 2025, 09:37:56 pm
content: Thank you for sharing.
First 4 layer PCB design - looking for some advice - Page 1
Forum section: electronics / projects

author: AronF
author_rank: Newbie
timestamp: August 02, 2020, 10:23:06 am
content: Hello everyone!I've been designing 2 layered PCBs for years, and here I was thinking that maybe I should try a 4 layered design in a not-so-demanding project.That not-so-demanding project turns out to be the driver/control board of a small drone with core-less DC motors.I've attached the schematic as a .pdf file -- Iknow there is a typo in the barometer.The first layer hosts the majority of the components, has the I2C bus, and the different supply rails for the boost, buck and LDO converters ( top.png ).The second layer is the ground layer ( ground.png ).The third layer is the VDD power plane for the digital circuits and the V+ for the motors ( power.png ).The last layer has the SPI lanes, some slow I/O traces and the RGB LED which must be on the bottom to be observable when (if) the drone flies. ( bottom.png ).For my untrained eyes, this setup is good enough, but I'm curious to find out, what could be improved on it?Thank you in advance.

author: bson
author_rank: Unknown
timestamp: August 03, 2020, 09:59:51 pm
content: Nothing immediately huge. You could rotate the programming connector at the center 90 degrees to shorten some circuitous traces, same in a few other places. But I doubt it makes any practical difference. You have a few rows of vias that are close enough to create gaps in the power and ground planes, but I doubt that makes any practical difference either. Purely cosmetically, Use the Grid Luke. (A few pins in a row, like at the top left, are a bit misaligned. Shrug.) The SPI trace (to the accelerometer etc?) aren't long in any absolutely sense.

author: AronF
author_rank: Newbie
timestamp: August 06, 2020, 08:16:19 am
content: Thank you for the advice.It took me this log to get back, because I was tinkering with the not so original version of the NRF chips. Found out that they require a huge bulk capacitor, so I'll add that on the board, and I'll try to align my components. Misaligned components bother me too, but sometimes the force of laziness is greater.I'll edit this comment when I have the new design.EDIT: The programming connector is rotated, the vias are spread apart, so the planes are not broken anymore. I replaced the 800mA LDO to an 1A one, since I have some concerns regarding the radio module. The rest is the same.
Power supply design power loss concerns. - Page 1
Forum section: electronics / projects

author: theworldbuilder
author_rank: Regular Contributor
timestamp: March 01, 2018, 12:03:58 am
content: So this is my first attempt at a power supply design.I'm aiming for a simple cheap design that will have a positive rail (0 to +12) and negative rail (0 to -12) and with up to 1 amp current available on each rail. I've also included a basic current limiting feature to pull down the output voltage. *The transformer is 240 to 2x12V*My main concern at the minute is the power loss in the regulators (LM337 and LM317) when Vout is down close to 0. Is their any simple way to minimise this power loss other than possibly making a custom transformer and tossing a few relays in there to switch supply voltages?Any other questions, comments, or criticisms on my design that might help me to improve it are welcome!

author: station240
author_rank: Unknown
timestamp: March 02, 2018, 03:39:18 am
content: Vdrop = Vin - VoutIf your outputting 1V, then you have 11V between the input and output of the regulator.Power loss is Vdrop x IoutSo 1V at 1A output results in 11V x 1A = 11W of power.If you don't wish your regulators to run that hot, you could use relays to switch resistors in to drop the voltage from the transformer.
First Circuit. Voltage Divider / Clipper for sound card measurements - Page 1
Forum section: electronics / projects

author: barbaroja
author_rank: Contributor
timestamp: November 23, 2021, 06:43:50 am
content: After a good read of Daqarta help,https://www.daqarta.com/dw_0all.htm, I decided to build the circuit. I am going to measure some higher voltage signals with an M-Audio ProFire 610. Circuit works and all is good.So to be completely clear:Objective: Get an AC signal (up to 80Vp) coming from vintage amps and EQs to not destroy the audio interface. Solution: Clip the signal with LEDs.Measured the interface inputs and it clips around 4.8Vrms. So I am clipping the signal now using the original circuit proposed in Daqarta help, with two LEDs, one green, one yellow for a Vdrop of 1.9+1.8=3.7V, which seems reasonable. I am actually using a 20K resistor. That, paired with the Zin of 10K (measured with a voltage divider) gives a gain factor of 0.33.So 2 things are important.1. Voltage gets divided2. Voltage gets clipped (and clipping does not destroy LEDs)However, I wanted to get a better signal clipping indicator. LEDs do not light properly when the threshold is just there so I tried to have that current going to ground to light them up.So I came up with this circuit:https://tinyurl.com/ygsvll5xI like it because it is my first. But I do not because Needs 2 leds, plus the intended "turn on quick" idea was still not there.I posted in Reddit (sorry if you are re-reading this) and a suggestion came:https://tinyurl.com/y3mjj2tsWhich I like but I do not understand at all.At this point I am open to suggestion, questions, ideas, explanations. I am truly a novice at designing circuits.
First clock project. - Page 1
Forum section: electronics / projects

author: Electro707
author_rank: Contributor
timestamp: March 02, 2017, 10:12:37 pm
content: Hello there internet. I have developed a fully working clock capable adding a temperature sensor all by myself. At the age of 16 this has been one of the best project i made so far. Here is a picture of it:http://imgur.com/a/0uj8LI used an RGB LCD because it would prettier on my desk while the animation runs. This clock has a backup battery so it could run even though it is unplugged. On the next version i want to be able to play the radio, have an alarm, and make it portable.WARNING: ONLY APPLY 5V TO THE CIRCUIT. MORE COULD BLOW IT AND LESS IT WOULD NOT WORK.Here is the schematic, Arduino file, and the case 3D file for anyone who wants to replicate this project. There is also a pcb gerber files in the project folder but i haven't tested it myself and it doesn't include the temperature sensor ability yet.https://drive.google.com/drive/folders/0B31WSjrLzZFPSDJZdTE5bm43cnM?usp=sharing

author: NivagSwerdna
author_rank: Super Contributor
timestamp: March 02, 2017, 10:58:08 pm
content: Looks great.
First design not done in ExpressPCB. I feel accomplished. - Page 1
Forum section: electronics / projects

author: sentry7
author_rank: Regular Contributor
timestamp: March 10, 2017, 01:14:43 am
content: Just a show off thread. Never used KiCad before, but a plain and simple 555 astable done in KiCad. Had to create a component and a footprint.Also, I have a feeling that me and thru-hole are gonna break up soon.

author: aylons
author_rank: Unknown
timestamp: March 10, 2017, 11:26:49 am
content: Congrats!

author: Rolo
author_rank: Regular Contributor
timestamp: March 10, 2017, 11:42:38 am
content: Nice ! Just installed KiCad myself.

author: brabus
author_rank: Frequent Contributor
timestamp: March 10, 2017, 03:06:49 pm
content: Well done!That looks like a really tiny electrolytic capacitor!
First PCB design (Z80 Microcomputer) - Final results - Page 1
Forum section: electronics / projects

author: sentry7
author_rank: Regular Contributor
timestamp: November 01, 2015, 02:32:15 pm
content: Hey guys,So this is an update on my first PCB which I introduced in the following threadhttps://www.eevblog.com/forum/projects/first-pcb-design-seeking-wise-council/.I also had some questions about how I should approach the diode protection circuit in this threadhttps://www.eevblog.com/forum/projects/protection-diode-placement/.In the end, everything turned out extremely well. Many of you had already guessed that this was a Z80 microcomputer. There was but one flaw in the design with the memory control logic, but fortunately, I could fix it with a jumper wire making the correct connections. As far as board assembly goes, the only issue was one bridge (fixed with a bit of braid). Thanks goes to everyone who gave advice. I attached an image of the final board.There is one other problem with this design. I planned for this board to be capable of running off of a 9V battery, but when I connect a 9V battery, nothing happens. I verified that there is an open circuit voltage when connected to the board, so the battery is giving power to the board. With some probing of the voltmeter, I found that the input voltage on the regulator is less than half the full 9V (around 3.4V). The output voltage on the regulator is not even a full volt (about 0.8V). I wonder if the battery simply cannot sink the current required? I attached a scheme of the power supply for reference.

author: mariush
author_rank: Super Contributor
timestamp: November 01, 2015, 02:49:57 pm
content: Replace the 9v battery with a power adapter and measure the current going into the regulator (or take 12v from the power supply of your computer) - it will be about the same as the current going to the circuit plus a few mA consumed by the linear regulator itself.9v batteries can't output lots of current, they really shouldn't be used for more than... let's say 100mA. Their high internal resistance means the voltage will drop as the current increases.In addition, you have a voltage drop of about 0.6-0.8v on the diode in front of the regulator, and the 7805 regulator itself needs about 1.5-2v above the output voltage to do its job.

author: sentry7
author_rank: Regular Contributor
timestamp: November 01, 2015, 02:57:50 pm
content: @mariush,That explains it. Thanks for the insight.
First project complete! Introducing Voxie - Keeping parents and kids connected - Page 1
Forum section: electronics / projects

author: cryptyk
author_rank: Contributor
timestamp: April 12, 2015, 09:03:32 pm
content: Thanks for the help from the guys in the beginner section! I just finished my first ever electronics project. I'm a software engineer who has always wanted to build something, and finally did. Heeeeeere's Voxie:

author: mtdoc
author_rank: Super Contributor
timestamp: April 12, 2015, 09:21:26 pm
content: Cool idea, I like it!I think for wider appeal you'll want it available in a different form factor though. For examlple my 6 and 9 year old boys would not be caught dead with a stuffed animal when they go off to summer camp.

author: pickle9000
author_rank: Super Contributor
timestamp: April 12, 2015, 09:33:37 pm
content: Nice and simple, congrats. Multiple form factors is a good idea. Don't forget grandma.

author: kjn4685
author_rank: Regular Contributor
timestamp: April 12, 2015, 09:40:39 pm
content: Very cool I think it would be a great idea, but security for the kids would be my concern, but other then that good idea. Thanks for sharing.

author: cryptyk
author_rank: Contributor
timestamp: April 12, 2015, 09:46:46 pm
content: Quote from: kjn4685 on April 12, 2015, 09:40:39 pmI was worried about the same thing! I made sure that nobody except for authenticated users can send voice messages to my boys

author: SL4P
author_rank: Super Contributor
timestamp: April 13, 2015, 06:14:12 am
content: Love It!My observation is that Quinn and Jax may tussle over it to reply 'to Dad', and you need to factor in those unexpected user circumstances e.g. If a new recording is initiated while the previous is still being sent... etc in all scenarios.Great idea - get your provisional patent (A$92) in as soon as possible so you can protect & sell it to Mattel, Hasbro or someone else!

author: zapta
author_rank: Super Contributor
timestamp: April 13, 2015, 02:23:22 pm
content: Excellent idea and well done. You can have a voxie also on the adult side.Hopefully mom's lawyer will also like this idea.

author: zapta
author_rank: Super Contributor
timestamp: April 13, 2015, 02:25:24 pm
content: Quote from: SL4P on April 13, 2015, 06:14:12 amProbably too late since it got disclosed to the public.(I am not a lawyer)
First Schematic - Page 1
Forum section: electronics / projects

author: jones12
author_rank: Newbie
timestamp: April 26, 2018, 07:53:15 am
content: Hey guys,I'm in the process of designing aa arduino controlled fan system that works off temperature (DHT11)I've got the code and prototype working so the next stage is the schematic.My first schematic was a write off, but I've read up on what I needed to fix and revised it. Hoping I've got it right this time!Im a third year electrical engineering student and believe it or not they teach us very little CAD in the course....Is this the right place to post it and ask for people to have a look at and offer their opinions?Its attached as a PDF but i'll include an image link below as well:Cheers all!Caleb.

author: hamster_nz
author_rank: Super Contributor
timestamp: April 26, 2018, 08:48:21 am
content: Is there question in there?On thing I am not so sure on is that it is hard to see that the PWM signal is connected to the gates on the MOSFETs.Ditto for the TEMP signal being connected to the DHT11.

author: Theobald
author_rank: Contributor
timestamp: April 26, 2018, 08:52:16 am
content: Hi Jones12,1) AVCC is not powered. Check user manual.2) Add a capacitor on the RESET pin, --> check the user manual for power on reset and it helps for EMC immunity.3) Just in case, add diode in the power supply plug. If the current is to high, place the diode in parallel and add a fuse.4) C4/C5 should have the same value. If X1's CL=12.5pF, keep 22p for both.Theo
First time laying out a PCB/Using Eagle, can someone double check my work? - Page 1
Forum section: electronics / projects

author: JGAN
author_rank: Contributor
timestamp: October 05, 2015, 08:21:42 am
content: I'm creating a custom Lipower for a project, and I did it all in Eagle for the first time. This is the first PCB I have laid out and I had to also create a custom component for the inductor. I'm mostly looking for some input on whether I did it wrong or what. There are some airwaves left for GND and I'm not sure how to fix it too...Mostly frustrated and want to go to sleep at this point. Any input is always appreciated.

author: FreddyVictor
author_rank: Regular Contributor
timestamp: October 05, 2015, 10:13:24 am
content: OK, on your new part, change the red box wires to a layer such as tPplace (use the Change tool) and change those Dimension arrows to layer tDocu so they won't actually be on the pcbon your actual board, add a box around the perimeter in layer Dimension which will define the actual pcb sizeare you really going to be using 0201 size parts, they really are very small ?would recommend 0805 myself

author: Josephine85
author_rank: Contributor
timestamp: October 07, 2015, 01:09:00 pm
content: Also check the PCBsim:http://www.cadsoftusa.com/eagle-pcb-design-software/additional-features/simulation/Quote
First time pick&place (video) - Page 1
Forum section: electronics / projects

author: mrkva
author_rank: Unknown
timestamp: July 20, 2015, 11:09:16 pm
content: It is the first time I was doing factory pick & place, so I asked the guys to make me a little video from the process.It is a great feeling to see your design be finally populated by these fast robots(If anyone is curious, it is this product:https://zvukolom.org/product/elektrosluch-3-pre-order/)
First time schematic for USB-C power detection - Page 1
Forum section: electronics / projects

author: Stealthrt
author_rank: Regular Contributor
timestamp: May 29, 2023, 02:37:41 am
content: Hey all I am creating a PCB that allows me to detect when I plug in a tablet, laptop, etc. to my home made tablet organizer. It's difficult to see if it made a connection in the back since you place the tablet in the front and slide it back:I'm using the INA219AxD and connecting the IN + and - between the 0.1/1% (PT2512FK-070R1L) resistor and having the - go to ground while the + is going to the VBUS_B line. I'm not real sure if this is the correct way to wire this in order to tell when a tablet is connected or not so that's why I need someone more knowledgeable to help me out.The A0 and A1 will have different resistors so that the I2c knows which one is calling out. But not sure what is needed for the 42, 43 and 45 configuration:0x40 = No solder0x41 = Solder A00x42 = ?0x43 = ?0x44 = Solder A10x45 = ?0x46 = Bridge A0 & A1I modeled the INA219AxD from the Adafruit schematic:​Here is my schematic:So if you can lend me a hand/knowledge or let me know if I'm even correct as-is? Maybe there's a better way of doing this?

author: adamcord
author_rank: Contributor
timestamp: May 29, 2023, 01:24:05 pm
content: Holy spaghetti batman. I didn't spend much time actually trying to decipher your circuit, because the schematic is a mess.Leave some space around stuff. There's no pressure to fit it All On One Page, unless you're going for some kind of award.Absolutely DO NOT run wires across schematic symbols! No "why not", just don't do it!Using some net labels to jump between functional blocks without running wires all over the place can be good. The right balance between use of wires and net labels needs to be struck.From what I can tell about your circuit, yeah that should be fine. Shunts, current sense amps, whack the signals into a micro, use the on-board ADC. Sure, why not. But clean up your schematic, make it more readable, then I'll come back and provide real feedback.

author: voltsandjolts
author_rank: Unknown
timestamp: May 29, 2023, 03:49:33 pm
content: Quote from: Stealthrt on May 29, 2023, 02:37:41 amHmm, this is a problem of your own making. I mean, you could plug the charge cable in, then slide the tablet back into the rack.

author: thm_w
author_rank: Super Contributor
timestamp: May 29, 2023, 11:59:52 pm
content: Another option is to use magnetic cables, they self align and "click" into place quite well.
Fish tank controller grounding problem - Page 1
Forum section: electronics / projects

author: FrankenPC
author_rank: Unknown
timestamp: March 21, 2014, 08:13:41 pm
content: So, I'm finishing my aquarium controller project prototype. One of it's automated processes is the monitoring of PH and TDS (dissolved solids). Unfortunately, the floating ground of the Arduino MCU is causing problems with the A/C mains grounding caused by various pumps in the tank. The desired ground path of earth is actually causing the 5V's from my probes to flow through the the tank to my pumps. This, of course destroy's any probe accuracy I might have.So, what if any protections must I take to tie my floating ground to earth ground to solve this problem?Thanks!Sad diagram... hopefully it gets the point across.
Five Phase stepper driver from the 90s... - Page 1
Forum section: electronics / projects

author: RocketMan69
author_rank: Newbie
timestamp: April 23, 2020, 06:23:38 pm
content: Hello, this is my first post here on this forum and i hope this is in the right section. I've been to a few other forums but get ridiculed over wanting to use old outdated tech however that is the point of this project alone. im building a highly accurate CNC (or attempting too) out of parts i FIND only. ive got a lot of understanding of the older through hole stuff and have traced the circuit im trying to repurpose. however im not much of a logic guy. which is where im stuck. the circuit is a mosfet based stepper driver using a couple of bcd counters and eproms which feed signals to a flipflop and mosfet driver type deal to control the high voltage side. im not trying to elaborate too much and get too wordy but i will include the circuit diagram i drew up. i plan on modifying what i need circuit wise and get new pcbs and all that but i cant seem to communicate with the board using an arduino. im sure its a relatively simple thing im just not getting right coding wise but im not too adept with the logic half of things like i said. by the way im self taugh as this has been my hobby since i could pick up a screwdriver. i know i dont know it all and im always willing to learn more. so please lets keep to the project and not how "uselessly old and inefficient" a 5 phase stepper motor is... i dont care, this is a pursuit of knowledge lolwith that said please educate me