hybridfree/eevblog-posts huggingface dataset:
Any good MOSFET tester schematic? - Page 1
Forum section: electronics / projects

author: zaoka
author_rank: Frequent Contributor
timestamp: October 17, 2011, 04:12:07 pm
content: I am looking for a good MOSFET tester schematic that test simply GO-NOGO and leakage.This is for good friend of mine who started learning electronics.

author: johnwa
author_rank: Frequent Contributor
timestamp: October 18, 2011, 11:30:09 am
content: Hi,For a simple go/no go test, I usually just hook the drain and source up to a bench power supply with a lamp in series. Touch the gate with one hand, and the positive terminal of the PSU with the other (assuming N-channel), and the lamp should go on, now touch the negative terminal and it should go off again. While this is a fairly crude test, in my experience MOSFETS usually either work or they don't - you don't really need to know any more.Make sure that you take appropriate antistatic precautions with the above test.Hope this helps,John
Any good off-the-shelf reflow ovens targeted at the hobbyist market? - Page 1
Forum section: electronics / projects

author: ksoviero
author_rank: Contributor
timestamp: July 26, 2021, 04:13:26 pm
content: Hi all,I've been looking to upgrade my hacked together toaster oven to a more professional style reflow oven that's better at reflow profiles, heating evenly, etc. However, while looking into it, there seems to really only be two options. The T962 clones that require quite a bit of work to get working and even then aren't great, or commercial reflow ovens that cost more than my car.So, are there any good reflow ovens targeted at the hobbyist market that "just work" OOTB?Thanks!

author: Pack34
author_rank: Frequent Contributor
timestamp: July 26, 2021, 06:46:29 pm
content: There's nothing really wrong with the T-962. I've used it for years. I believe I updated the firmware to the UnifiedEngineering one on github. It seems to run a bit smoother with it. The original firmware that shipped with mine was a bit quirky with the responsiveness of the buttons. The UE firmware fixed that and you can add an additional thermometer for cold junction compensation.https://github.com/UnifiedEngineering/T-962-improvementshttps://www.ebay.com/itm/234091108407?hash=item3680ead837:g:wLYAAOSwaS1g8M4-

author: ksoviero
author_rank: Contributor
timestamp: July 26, 2021, 07:18:45 pm
content: Quote from: Pack34 on July 26, 2021, 06:46:29 pmThat's fair and may be what I actually end up doing in the end, but I was hoping for something a little more professional, e.g., better input protection, the ability to import and export reflow profiles and history, etc. Using 3D printers as an analogy, if the T962 is the original Ender 3, then I'm looking for something closer to an Ultimaker.
Any good sources for laying PCBS for RF? - Page 1
Forum section: electronics / projects

author: bseishen
author_rank: Contributor
timestamp: March 08, 2016, 06:38:18 pm
content: Any good books/sources for helping the inexperienced in do's and dont's of RF transmissions lines on PCBs? Thanks!

author: bseishen
author_rank: Contributor
timestamp: March 08, 2016, 06:39:23 pm
content: Oh, I have a project that will be in the microwave range 2.4/5.8Ghz.

author: Apollyon25_
author_rank: Regular Contributor
timestamp: March 13, 2016, 09:02:18 pm
content: I use Saturn PCB calculator frequently - there are loads of other online transmission line calculators though.Its all geometry and layer stacks creating 50 ohms - nothing too difficult.

author: rfeecs
author_rank: Frequent Contributor
timestamp: March 14, 2016, 01:27:16 am
content: Just Google microstripSome other search terms:microstrip discontinuitycoplanar waveguide

author: bseishen
author_rank: Contributor
timestamp: March 14, 2016, 01:40:58 am
content: Thanks!
Any help would be appreciated - Page 1
Forum section: electronics / projects

author: robjodicarter
author_rank: Regular Contributor
timestamp: October 25, 2018, 01:43:16 am
content: I have this project I'm going to dive into, I think I will start with an Arduino. But it may be done easier. If any one has an idea please let me know!!! Most of the outlay you see will be filled with red or white LED's. Again any help would be awesome!!!!!RobSent from my PH-1 using Tapatalk
Any idea for straight line motion of blind people - Page 1
Forum section: electronics / projects

author: wolfrum
author_rank: Newbie
timestamp: October 05, 2011, 04:03:09 pm
content: I am working on a project to help blind people move from one place to another without a stick.I already make a obstacle detection and other guiding mechanisms but how to make a blind man move in a straight line ? How to guide a blind man stick to a footpath on a road?Any sensors or guiding mechanisms?

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 05, 2011, 05:33:47 pm
content: compass and beep maybe.

author: ciccio
author_rank: Frequent Contributor
timestamp: October 05, 2011, 06:44:21 pm
content: Interesting project.I'm wondering where the blind person must walk straight: in a city center? Over a sidewalk that s higher than street level? What about following, with a sonar device or something optical, the sidewalk's edge?At the intersections, a GPS-like system may talk to the person and give her the choice of going straigh, turn left or right.Or a GPS system may guide the person along her march..This can work even outside the city center.In a city, could be easy to pose cables, or to use the cables already up in the air to carry a RF signal.This may be received by something..There are even integrated Gyroscopes :http://parts.digikey.com/1/parts/2514977-ic-gyroscope-angular-16soic-adxrs453brgz-rl.htmlI know, it is easy to write about the first ideas that come on, and they can be unrealizable..Hope that your work will have good results.Regards

author: vk6zgo
author_rank: Super Contributor
timestamp: October 06, 2011, 06:11:02 am
content: Get input from blind people.THey spend their whole life with the problem,& can tell you when you are following a dead end path in your development.VK6ZGO

author: dequo
author_rank: Contributor
timestamp: October 07, 2011, 06:41:32 am
content: vibrations bro, like if theres something to their right, a vibrating collar around their right ankle would let them know

author: daedalus
author_rank: Regular Contributor
timestamp: October 09, 2011, 11:47:32 am
content: When I was an undergraduate, one of my peers did a similar project. What he built was basically a haptic torch, he took a torch body, fitted an ultrasonic ranger into it, then provided distance feedback to the user with a small hobby servo. The hobby servo had a moving post that pressed against the users thumb, indicating the distance. The thing worked pretty well, you could navigate indoors with it after a bit of practice.Is this a university project you are doing?

author: TheWelly888
author_rank: Frequent Contributor
timestamp: October 09, 2011, 05:46:49 pm
content: Quote from: wolfrum on October 05, 2011, 04:03:09 pmNon electromechanical solution but more biomechanical solution:http://www.guidedogs.org.uk/
Any idea why my fet is turning off like this on the LM5106? - Page 1
Forum section: electronics / projects

author: Daveedius
author_rank: Contributor
timestamp: August 23, 2022, 09:46:43 pm
content: I've designed a half-bridge driver circuit using the TI LM5106 and am seeing peculiar behavior when the high side fet turns off.At first, it turns off well, but once it reaches supply voltage, it stays there for about 50ns before turning off all the way.This is an issue because it's interfering with my soft-switching as the delay is allowing the low side fet to turn on before the high side has fully turned off. The behavior is present only on the high side; low turns off fine.Any idea why this is happening or ideas on what I can try to fix the situation?

author: thm_w
author_rank: Super Contributor
timestamp: August 23, 2022, 10:27:00 pm
content: Please rotate your images.Some discussion here that may or may not be relevanthttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/819604/lm5106-lm5106-erratic-switching-killing-mosfets

author: jmelson
author_rank: Super Contributor
timestamp: August 23, 2022, 11:59:02 pm
content: Quote from: Daveedius on August 23, 2022, 09:46:43 pmThis looks like the Miller effect. As soon as the gate charge starts to be removed, the VDS starts to go up, and the capacitance between drain and gate fights the gate driver. If you need faster turn-off, you need a more powerful gate driver and less resistance in the gate drive.Also, resistor-diode-capacitor circuits to adjust deadtime are best done on the INPUT to the driver chip.Jon

author: Daveedius
author_rank: Contributor
timestamp: August 24, 2022, 06:44:12 pm
content: Thanks Jon. I agree it really looked like that but turns out, it was just me being dumb. I was referencing HO to ground rather than to HS. Richard over at TI figured it out for me:https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1128682/lm5106-why-is-the-high-side-fet-turning-off-like-this/4187964#4187964
Any Ideas about a 210VDC ~ 1800VDC  input power supply? - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 11, 2024, 11:19:05 am
content: I Have seen this power supply that has a 5W 5V/1A out put from a 210VDC ~ 1800VDC, I wonder what topology or circuit they have used, and Ideas?See the specs for the Auxiliary Power (PWR-DC1500) in the attached PDF catalogue.

author: Manul
author_rank: Super Contributor
timestamp: November 11, 2024, 03:35:17 pm
content: The input range is indeed very wide. I would probably go with two switch forward converter using SiC mosfets.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 12, 2024, 12:46:17 pm
content: The price is unbelievably low, the price for the whole 24 input package is around 50$So I do not think they have used such thing, Maybe a buck convertor? I do not have the unit for now, so I can not open it to see what's inside

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 13, 2024, 11:12:21 am
content: I'm wondering if it could be done with old tech, something like TL494 in a buck config, what's your Idea?

author: Manul
author_rank: Super Contributor
timestamp: November 13, 2024, 11:39:18 am
content: I don't know. It would be very hard to achieve such high step down ratio (1800V/5V) with a buck topology. Furthermore, I think it should be isolated topology. So maybe one/two switch forward or flyback.

author: Andy Chee
author_rank: Super Contributor
timestamp: November 13, 2024, 08:40:06 pm
content: I think you'd definitely want two switch topology with such high voltages.This saves the hassle of primary side clamping/snubbing of kV voltages!

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 14, 2024, 11:00:12 am
content: QuoteSo what cheap choices do we have in this topology? and recommended part numbers?

author: Andy Chee
author_rank: Super Contributor
timestamp: November 14, 2024, 11:15:00 am
content: Practically any PWM controller is capable of driving a two switch forward or two switch flyback, including the TL494.
Any ideas how to program this thing? - Page 1
Forum section: electronics / projects

author: Rasterist
author_rank: Contributor
timestamp: April 15, 2024, 05:20:41 pm
content: I received a roughly .375" thick political mailer, and when I opened it a video began playing on an included display and speaker. I cut/tore off the surrounding cardstock to reveal what you see in AFP.JPG (the displayed image actually looks surprisingly good; it's borked here because the camera is off-axis). There's a USB C port and the sender included a short USB A-C cable. When plugged into my PC, the device does not show up in File Explorer (Windows 10), but the Intel Rapid Storage Technology app (which I've never seen before) launches (Intel rapid.JPG).I was hoping this could be easily repurposed by simply dragging over a different video file, but I can't find any way to do that after clicking around inside the Intel app, and since it doesn't show up in File Explorer I'm at a loss. Any ideas?

author: jpanhalt
author_rank: Super Contributor
timestamp: April 15, 2024, 07:28:56 pm
content: I doubt it is reprogrammable, and the chip is probably a black epoxy blob. I find it amazing that microcontrollers and lCD's are so cheap they can be sent by bulk mail in the US today as advertising. I got a less elaborate car ad a year or so ago.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 16, 2024, 12:58:04 am
content: could be a simple as : to put some name "crafted image or video files", anything you put is played ... seen that in the past, or you need more careful teardown to show us the innards ..

author: amyk
author_rank: Super Contributor
timestamp: April 16, 2024, 02:53:25 am
content: Does anything show up in Device Manager? It's usually easier to discover what they show up as in Linux. You might need to stop the video or otherwise get it into mass storage mode; they can't both play from and expose the internal flash as mass storage at the same time.Quote from: jpanhalt on April 15, 2024, 07:28:56 pmI don't think video players have gotten to the point of COBs yet. Look under the display for the controller and rest of the circuitry. It seems similar to this:https://www.eevblog.com/forum/projects/now-what-can-i-do-with-120x-of-these/More info on a different one:https://gist.github.com/probonopd/33d94169ceaacc33e814

author: jpanhalt
author_rank: Super Contributor
timestamp: April 16, 2024, 08:39:59 am
content: @amykPerhaps so. The LCD advertisement I got just gave a numeric code.
Any ideas on how to offset a sensors output without an op-amp - Page 1
Forum section: electronics / projects

author: sofa-king
author_rank: Contributor
timestamp: December 20, 2022, 01:49:52 am
content: I'm using an ambient light phototransistor to control the brightness of a display. The ADC is the lousy one in the ESP32 which essentially has no reading changes below about 100mv. The problem is I need to detect both absolute darkness, very bright lighting and typical indoor light levels. So to be more concise I need to be able to measure below 100mV. My thought is to just add an op-amp to the design and add a small offset (0.1v), but I'd really like to avoid the extra components if I can find a practical solution. The phototransistor is just a typical circuit with the collector connected to 3v3 and a resistor connected to the emitter and ground.any ideas will be greatly appreciated!

author: uer166
author_rank: Super Contributor
timestamp: December 20, 2022, 02:10:52 am
content: If you're going to add an active external part, you might as well add literally any ADC on a SPI bus that would actually work, instead of using the broken-by-design ESP32 analog peripherals. Alternatively, you can do a 3-way resistive divider to pull up the "zero" output of photo-device above 100mV.

author: ledtester
author_rank: Super Contributor
timestamp: December 20, 2022, 04:35:34 am
content: Here's what uer166 is talking about:Code:3.3V --/\/\/---ADC---/\/\/-- VinR1 R2The formula for the voltage at the ADC pin is:$$V_{adc} = V_{in}\frac{R_1}{R_1+R_2} + 3.3 \frac{R_2}{R_1+R_2}$$All that matters is the ratio between R1 and R2, so setting R1 = a*R2 we have:$$V_{adc} = V_{in}\frac{a}{1+a} + 3.3 \frac{1}{1+a}$$If you want the ADC to read 0.5V when the input is 0V, you would solve:$$0.5 = 3.3 \frac{1}{1+a}\quad\Rightarrow\quad 1+a = 3.3/0.5\quad\Rightarrow\quad a = 5.6$$So if R2 = 10K, R1 would be 56K. The final formula for the ADC voltage would be:$$V_{adc} = V_{in}\frac{5.6}{6.6} + 0.5$$

author: sofa-king
author_rank: Contributor
timestamp: December 20, 2022, 06:08:07 pm
content: Thank you for your replies!Does this look right?

author: ledtester
author_rank: Super Contributor
timestamp: December 20, 2022, 07:14:49 pm
content: Well, the formula I gave assumed the output impedance of Vin was 0. The output impedance of the phototransistor is likely to be high so you would have to experiment with the resistor values and I'm not sure how well it would work.How about putting the resistor on the collector of the phototransistor? Then the voltage at the ADC will start from 3.3V and go downwards and you'll avoid the bad part of the ESP32's ADC.

author: sofa-king
author_rank: Contributor
timestamp: December 20, 2022, 09:00:59 pm
content: Thanks again for your reply. Unfortunately the ADC in the ESP32 doesn't differentiate between ~3.2-3.3v either. The ADC is really quite badI think I'll experiment with some resistor values and see if I can get reasonable readings. Accuracy is not all that important so I might be able to get it to work.I'm guessing this is a bad idea:
Any ideas what this IC does? - Page 1
Forum section: electronics / projects

author: Mario87
author_rank: Frequent Contributor
timestamp: August 03, 2019, 04:06:29 pm
content: Hey all, as per the title really, I have an IC on a board and no idea what it does. The only marking on the top is "5C". I've uploaded a couple of pics below. On the first image the IC is circled in red with pin 1 marked by the red dot next to it. The 2nd image shows the IC removed.The IC interfaces with the sim card slot that would normally be below it, on the left of the board.Pinouts appear to be as follows....Pin 1 - CLK pin on Sim Card SlotPin 2 - GNDPin 3 - Not ConnectedPin 4 - VCC pin on the Sim Card Slot and the decoupling capacitor located to the right of the ICPin 5 - RST pin on the Sim Card SlotPin 6 - I/O pin on the Sim Card SlotSo it clearly interfaces with the sim card and does something, the question is what?!Anyone got any ideas?Thanks

author: james_s
author_rank: Super Contributor
timestamp: August 03, 2019, 04:17:16 pm
content: Is it a supervisor IC? The fact that it interfaces with reset suggests it might be.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 03, 2019, 04:30:11 pm
content: Given it connects to PS and IO pins of the SIM card, I'd suspect it could be some kind of transient voltage suppressor.The following gives you a few references to look at:https://smd.yooneed.one/code3543.html

author: DaJMasta
author_rank: Super Contributor
timestamp: August 03, 2019, 04:34:15 pm
content: Yeah my guess would be TVS as well, I know of a few for use on USB data lines in that form factor... that said, the pin connections would make more sense as some sort of supervisor, but I don't know of this being required in other sim card designs.Does it operate? Could you scope the pins and see if it's doing something active? Maybe diode check out of circuit to see if you can buzz out some TVS diodes instead?

author: IDEngineer
author_rank: Super Contributor
timestamp: August 03, 2019, 04:45:55 pm
content: Another vote for a TVS, a multichannel one since you traced three signals to it and it has connections to both supply rails. Any markings on the bottom of the package?

author: Benta
author_rank: Super Contributor
timestamp: August 03, 2019, 04:50:07 pm
content: Yep, ESD protection array.

author: Mario87
author_rank: Frequent Contributor
timestamp: August 03, 2019, 04:58:12 pm
content: Thanks all! After seeing the posts above I did a bit more digging and found schematics of another circuit, very similar to the one I am working with. Funnily enough, there is a 6-pin IC connected to the Sim Tray Slot in a very similar fashion and it's called out as "SMF 05C".After a quick google, this is indeed a TVS Diode Array for ESD protection.Even found the datasheet....https://www.semtech.com/uploads/documents/smf05c.pdfMany thanks all!
Any info on Motorola ZC400012P microcontroller?  - Page 1
Forum section: electronics / projects

author: DMartens
author_rank: Contributor
timestamp: November 22, 2021, 12:53:53 pm
content: Hi ... have an old CD player with many Philips components in it as well as a Motorola ZC400012P microcontroller ... does anybody have details on this? ... architecture ... speed ... 8bit? ... I dont see an external ROM, so I presume there is a facture-configured ROM inside ... best of all would be a datasheet of course ... cant find anything of value on the web ... thanks in advance

author: amyk
author_rank: Super Contributor
timestamp: November 22, 2021, 02:40:25 pm
content: ZC prefix is a custom device. Post its package/pinout and it might correspond to some existing MCU (probably 68xx) that they have, or it might not. It's probably mask ROM.

author: CJay
author_rank: Super Contributor
timestamp: November 22, 2021, 02:50:56 pm
content: Also post model number of CD player as Phillips had pretty good service info and there may well be clues if not an actual Moto part number on the schematic or even the parts list.

author: DMartens
author_rank: Contributor
timestamp: November 22, 2021, 02:59:31 pm
content: Thanks CJay and amyk for the initial feedback ... the CD player is not from Philips, it is actually a Mission DAD5 ... but mostly Philips chips ... found user manuals for the DAD5 but not (yet) the service manual ... thanks

author: CJay
author_rank: Super Contributor
timestamp: November 22, 2021, 10:52:13 pm
content: Ah, I see.Is the board silk screened Mission?Phillips made a lot of CD player 'kits' which were intended for use by manufacturers to get a jumpstart into the market and those boards/mechanics turn up in a *lot* of places you'd not expect them (Bang and Olufsen used them for instance)

author: DMartens
author_rank: Contributor
timestamp: November 23, 2021, 04:40:39 pm
content: No CD player brand or model on the silkscreen of the PCB ... Mission DAD5 is printed in the top left of the front panel of the player above the On/Off buttonAny suggestions where I can find the service manual / schematics for the DAD5?

author: CJay
author_rank: Super Contributor
timestamp: November 23, 2021, 06:08:40 pm
content: I've just googled that chip, the board images that come up for your 'Mission' show what looks *very* much like a Phillips OEM board.I suggest you look for part numbers on the board itself and see if you can cross reference it to a Phillips model number.
Any info on this intel F32-408833 IC? - Page 1
Forum section: electronics / projects

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: October 04, 2022, 11:51:34 am
content: it hints that it's licenced from intel, made by winfield.Quoteit's from an electronic typewriter, I'm building a winding machine and was thinking of using this to control it, since a winder is basically a typewriter but faster right?I can't find any info on it, at first I thought it was some 8088 de-graded clone but nothing lines up.it drives stepper motors trough a ULN2003A driver chips, also has a keyboard that connects directly trough it so it obviously is capable of doing some kind of multiplexing.crystal is 12khz, connects to pins 18 and 19ground connects to pin20, +5V to pins 20 and 31. it's a DIP40 packageI'll draw a schematic of the board if it helpsany info on this or even just a similar IC would be helpful!

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: October 04, 2022, 12:56:30 pm
content: I would lay a bet that it is a custom mask programmed 8051.

author: wraper
author_rank: Unknown
timestamp: October 04, 2022, 01:02:49 pm
content: Yes, considering 1980 copyright date, this thing should at least have 8051 core, more likely just a usual 8051 with mask rom. i logo implies it was made by intel. Likely you can even read its ROM.

author: wraper
author_rank: Unknown
timestamp: October 04, 2022, 01:11:21 pm
content: 8031 has no ROM, 8051 has mask ROM, 8751 has OTP EPROM (programmable only once). Only 8751 with quartz window (not usual plastic one) can be reprogrammed after UV erase.
Any info welcome for Planar EL560-400LP display and PS512-3 power supply - Page 1
Forum section: electronics / projects

author: Bendba
author_rank: Regular Contributor
timestamp: May 21, 2017, 02:11:36 am
content: Hi,I recovered a very nice display from a piece of medical equipment (vitals monitor)And I am trying to work out how it works.There is a ribbon cable going to the power supply and another connecting the power supply to the display.I worked out most of the wires, two for positive supply, two for 5v supply, two seem to not be connected, 2 for ground and 8 strait to the display.I was expecting to find at least 10 going strait to the display (8 bit data and at least 2 control lines)I am only guessing the input voltage should be 12V (all caps are 25V, except for a 200V on the high voltage side) and the PWM controller has a turn on/off threshold voltage of 8+-0.4VBut when I feed 12V, nothing happens. I can't find what I'm missing. So any help would be greatly appreciated. (Even better would be manuals and datasheets)

author: Bendba
author_rank: Regular Contributor
timestamp: May 21, 2017, 01:51:41 pm
content: Well, apparently, I wasn't searching hard enough, for the right thing.Since I found out what I needed, I might put it up here, just in case someone else is looking for the same thing.I was desperately searching for datasheet for the supply unit. I eventually found a manual for the display itself here:https://www.eldisplays.com/el560-400-lp/Direct link to the manual:https://www.eldisplays.com/content/EL560.400-LP.pdfI couldn't get dc to dc converter to turn on because there is an active low line between it and the display. The display pulls it low when receiving video data.Also, it was not, as I first thought a 8 bit data bus, but it is serial. One clock line, one data line, one line for vertical sync, one line for horizontal sync, four grounds.A quick test with a picaxe to confirm it works. Of course, I didn't get to display an actual image with the picaxe, the basic is way too slow to generate one. Enough to generate one line and scroll it down the screen. Pretty nice screen, it doesn't seem to have any minimum scan rate.All in all, scored a $1000+ display from the scrap.I think I'll make it the display for my Z80 project, I'll probably dedicate a processor to image processing and enough memory to make it work with two banks big enough to hold a full frame and switch between banks to display.I'd have one question though.Would a capacitive touch screen sensor work in front of an electroluminescent display or will the high voltage switching mess up with the sensor?If so, is there any other good option than resistive?Thanks

author: jry
author_rank: Newbie
timestamp: July 09, 2017, 02:55:21 pm
content: what piece of equipment did that come out of ?I may be interested in one or two

author: mrmsf
author_rank: Newbie
timestamp: August 20, 2017, 05:43:52 am
content: Hi can you tell me what equipment you found the display in?I need one that is bad.ThanksM
any interest in a oshw bias supply? - Page 1
Forum section: electronics / projects

author: batterypowerguy
author_rank: Newbie
timestamp: September 06, 2014, 12:44:45 am
content: It occurs to me that there might be some desire for a design for a bias supply for various op amp and transistor biasing. I have a design I typically use with a LT3803 and cooper vpack transformer, gives you isolated outputs and I typically use the flyback energy with a charge pump to control high side switches. If there is some demand I will do a compact layout in eagle and see about kitting it on tindie. basic specs would be 9-32V in, 1 non isolated and 2 isolated outputs @ approx 15V. this gives you some options for a +/- 15V opamp rail and I will probably build the charge pump in as well.

author: Smokey
author_rank: Super Contributor
timestamp: September 06, 2014, 02:12:40 am
content: How much current on each output?

author: David Hess
author_rank: Super Contributor
timestamp: September 06, 2014, 02:47:47 am
content: Regulation and noise will not be all that good using the LTC3803 and it requires a load on the non-isolated output.What about using a small inverter and regulating the input while compensating for the voltage drop of the output diodes? Many integrated switching regulators can be configure to do this.

author: batterypowerguy
author_rank: Newbie
timestamp: September 06, 2014, 04:04:51 am
content: Quote from: David Hess on September 06, 2014, 02:47:47 amregulation doesnt have to be that good for a bias supply, and will be load dependent to a degree, typically the Q current is more than plenty to keep it stable. That works too but there are advantages to having an isolated bias, IE you can reference it to your input voltage and then have a 15V float above the input to do various things with.i typically use supplies like this when doing analog bit to get across the isolation barrier to digital ground, or for high side switching.
Any IO-Link experts out there? - Page 1
Forum section: electronics / projects

author: mubes
author_rank: Regular Contributor
timestamp: May 16, 2018, 09:58:54 pm
content: Folks,I'm having terrible trouble getting an IO-Link device to talk to me. Hoping there are some experts here who can point out whatever I'm doing wrong. The device itself is a SICK IMB12-04BPPVC0K proximity sensor, which is a IO-Link 1.0 device at COM1 (4800 baud). I've done all the merry dance required in the IO-Link spec with the result that I've now got the output shown in the scope shot below, direct from the I/Q signaling line. Some notes;1) The WKUP pulse is exactly 80uS long. In this specific scope shot I've produced below there's not the resolution to show that, but it is.2) If I set C/Q high (by means of putting a piece of metal in front of the sensor) I can see it go low for 100mS in response to the WKUP pulse...so I'm reasonably confident that is working correctly.3) I'm following the spec by trying to initialize at COM3, then COM2 and finally COM1. I wait 50mS between wakeup cycle attempts (Tdwu) per the spec. The shot shows all three speeds, with the scope set to decode COM1...you can see the 0xA2,0x00 sequence decoded which is correct (I believe) for a MinCycleTime inquiry...Ignore the 0xFD, that just the higher speed data being mis decoded.4) I am using even parity, and the scope confirms it's being sent correctly.5) If I physically remove the sensor, the line floats to around half L+ in between my actively driving it. The implication is that the sensor is actively, and deliberately, pulling the line down (in the light of point 2 above)....its ignoring me on purpose, not by accident.So....I'm stumped. I've obviously tried things like varying the timings, just connecting at COM1 etc. etc. all to no avail. I'm pretty certain I'm just doing something wrong, but I have no idea what at the moment. If there's anyone out there with a COM1 IO-Link device who can scope me a working version of this startup sequence I would be eternally grateful since that gives me something to compare against...other suggestions for what to try next also gratefully received!RegardsDAVE

author: mubes
author_rank: Regular Contributor
timestamp: May 17, 2018, 10:48:49 am
content: Yup, problem between screen and keyboard. Turns out it communicates at COM2. Doh.For reference, since the lack of working examples was one of the big problems I had, a scope shot of the working initialisation is attached for when someone else needs it.
Any low-cost dual USB ports (USB + USB-C) flash drive teardown PCB photos? - Page 1
Forum section: electronics / projects

author: Georgy.Moshkin
author_rank: Frequent Contributor
timestamp: August 26, 2025, 07:30:59 am
content: I am interested in how the USB terminations are made and how long the traces are. Especially the cheap ones with no additional circuity. Do they use series resistances on DP/DN, so the unconnected side stubs open-circuited stubs are seen through ~10 Ohm resistors?

author: magic
author_rank: Super Contributor
timestamp: August 26, 2025, 08:00:42 am
content: It would be interesting if they are doing it at SuperSpeed, but 480Mbps works out to ~2ns per bit which means that 1 bit is 40cm long in the cable. So at high speed they are probably getting away with doing nothing special with those unterminated stubs.
Solved, obsolete. - Page 1
Forum section: electronics / projects

author: evb149
author_rank: Regular Contributor
timestamp: July 02, 2022, 03:17:08 pm
content: Solved, obsolete.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: July 02, 2022, 11:30:53 pm
content: Well, the cheap mics are good enough for what people expect of them. IMO, SNR isn't their strong point, but it's good enough. The best inexpensive high volume stuff comes from Knowles-https://www.knowles.com/department-details/dpt-microphonesLook at their MEMs product line. I know some of them go way higher than the published numbers, in fact I had an old series that was good to about 200 kHz. Don't know about the new ones.If you want seriously good electrets you have to pay a lot more. The common brands will set you back $1k, give or take a bit. You can get similar performance for a tenth of that fromhttps://cnaihua.en.alibaba.com/minisiteentrance.html?spm=a2700.wholesale.cordpanyb.2.75a07085RROMul&from=detail&productId=1600397131924I've used several of their electrets and their USB measurement mic and the quality is excellent.

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 02, 2022, 11:47:07 pm
content: Take a look at this project:https://github.com/loudifier/OpenRefMic
Any MP1584 Constant Current Designs out there? - Page 1
Forum section: electronics / projects

author: UPI
author_rank: Regular Contributor
timestamp: April 14, 2016, 09:29:44 pm
content: I am considering switching from LM2596 buck converters to the MP1584EN because the 1584 would save a lot of board space/cost since it runs up to 1.5mHz.Does anyone have any designs out there for a CC circuit MP1584 that will do 500mA at 14V out with an input of 24V?

author: langwadt
author_rank: Super Contributor
timestamp: April 14, 2016, 10:45:32 pm
content: Quote from: UPI on April 14, 2016, 09:29:44 pmtake the usual config for 24V to 14V, but replace the usual voltage divider on FB with your load and a 0.8V/500ma= 1.6R resistor to ground?

author: UPI
author_rank: Regular Contributor
timestamp: April 14, 2016, 11:26:07 pm
content: I should clarify: It should be constant voltage with a 500mA current limit.I believe your solution will only work for a constant load such as an LED. I am charging supercaps with a maximum of 14V that is limited to 500mA.

author: UPI
author_rank: Regular Contributor
timestamp: April 15, 2016, 02:16:29 am
content: I would like to be able to limit the output current to a max of 500mA at 14V.I need to come up with values for R1 - R5 in the attached schematic. I am not sure how to calculate them or if there is a circuit already designed that I can use.

author: UPI
author_rank: Regular Contributor
timestamp: April 15, 2016, 04:11:22 am
content: The LMP8646 Precision Current Limiter looks like it will do what I need and there is a webench calculator to set it up for varying switching or linear regulators with a feedback pin.Looks very nice.http://webench.ti.com/webench5/LMP8646/

author: langwadt
author_rank: Super Contributor
timestamp: April 15, 2016, 07:14:20 pm
content: if you don't need it to super accurate something like this might work:

author: UPI
author_rank: Regular Contributor
timestamp: April 15, 2016, 07:32:34 pm
content: I like it! As long as it is relatively stable w/o a ton of overshoot or oscillation, it could do the trick. We will test it out in a few hours.Thanks for your suggestions.

author: nickba
author_rank: Newbie
timestamp: October 11, 2023, 12:11:28 pm
content: Hello,I know it is an old topic, but I have the same question about CC for the MP1584EN. Unfortunately the picture posted by langwadt is no longer available. Any suggestions?

author: langwadt
author_rank: Super Contributor
timestamp: October 11, 2023, 01:43:24 pm
content: Quote from: nickba on October 11, 2023, 12:11:28 pmthey were doing some work on the servers, it should be back now

author: nickba
author_rank: Newbie
timestamp: October 12, 2023, 07:18:54 am
content: Quote from: langwadt on October 11, 2023, 01:43:24 pmThank you!
Any one can tell me the spec of this thermal camera? - Page 1
Forum section: electronics / projects

author: sam1275
author_rank: Frequent Contributor
timestamp: April 27, 2014, 11:54:03 am
content: Hello, I need the specification of "ISI vision 3" TIC, but I can't find it anywhere, can anyone help me? Many thanks.

author: Fraser
author_rank: Super Contributor
timestamp: May 27, 2014, 05:13:55 pm
content: From memory its a fire-fighting camera fitted with a Raytheon 320x240 pixel BST imaging core. As it is BST it has a shutter wheel between the lens and FPA. As it was designed for fire fighting it may also have the separate temperature pyrometer and a small visible light camera. Image was monochrome and sensitivity pretty good. Nice images but little control over them as it is designed to be easy to use so auto setting in most areas.From what I have heard from others it appears to have not been the most reliable of cameras.A pile of them appeared on e*ay recently.I would expect the spec to be similar to the EEV ARGUS 2 camera as they use similar BST cores.All this from distant memory so do not take it as Gospel.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 27, 2014, 05:26:15 pm
content: Just found this page......http://www.safetyonline.com/doc/vision3-0001Not that much true detail but at least it confirms my memory of it being a BST Core.Aurora
any one know such RFID reader? - Page 1
Forum section: electronics / projects

author: alireza7
author_rank: Regular Contributor
timestamp: March 02, 2018, 08:23:47 pm
content: hido you know such RFID reader that have these specs ?iso 14443 / iso7816mifare desfire cardsam slot-40 to 85 celsius degree (or at least 0 to 50)having interface appropriate for connecting to a micro controller (not just compatible with windows , Linux , ...)

author: dgtl
author_rank: Regular Contributor
timestamp: March 02, 2018, 08:49:05 pm
content: There are such RFiD reader IC's, that you connect via SPI to your uc; most of the work is done in this one ic and you need some passives and an antenna. For example, NXP has PN7xxx and CLRC663 series; ST has some and some others as well. The manufacturers provide software libraries to talk to most common tags without too much work. You can copypaste the evaluation board pcb layout for easier hw development. If you are not developing your own board, some vendors (ie sparkfun) sell arduino-like modules etc.When designing your own board, the antenna tuning is a tricky thing to get right (there are some capacitors, inductors and resistors for matching the on-board antenna to the chip). With simple tools and some trial and error, you can get decent tuning (ie 3/4 read range of the best possible); for very good tuning, it takes a lot of specialized tools and know-how. Also, the enclosure and all nearby metals to the antenna affect the tuning, so going with an existing reader may even force you to re-tune the antenna matching circuit it read range is important for you.

author: alireza7
author_rank: Regular Contributor
timestamp: March 02, 2018, 09:15:36 pm
content: the thing that i didn't mention is that i also need my rfid reader have SAM slot (secure access module) .can you explain me what is sam exactly ? can i design it's slot on my board?i was looking forward to such complete modules : acr1252uhttps://www.acs.com.hk/en/products/342/acr1252u-usb-nfc-reader-iii-nfc-forum-certified-reader/i may consider designing my own rfid reader but using a stock module is in Priority

author: alireza7
author_rank: Regular Contributor
timestamp: March 03, 2018, 11:36:36 am
content: also i found this module : DE-ABCM_TBhttp://www.duali.com/eng/nfc-product/nfc-module/built-in-antenna-module.htmlit seems a good module , do you have any idea about it? or do you have any suggestion?
Any open-source (of publicly free) DC test loader aimed at computer PSUs? - Page 1
Forum section: electronics / projects

author: LeonR
author_rank: Regular Contributor
timestamp: April 23, 2018, 01:42:27 pm
content: I've been looking for this for a while and couldn't find a project specifically about Computer SMPSUs aside from strudinox's one:There are commecial products available like SunMoon's, but they cost/shipping is prohibitive for hobbyist use.Reliable testing on such PSUs require cross loading on minor rails (3.3/5V) for proper 12V testing, AFAIK.

author: xani
author_rank: Frequent Contributor
timestamp: April 23, 2018, 02:20:45 pm
content: I doubt you will find anything cheap considering the power and number of outputs of some ATX supplies.You'd basically need at least 5 CC loads (+5, +5VSB, -12, +12, 3v3V) and possibly many more, like for example800W power supplycan havesix+12V rails, of course you cant load all of them to full power but still that's 10 outputs in total to load.So either DIY few CC loads, put it in common box and drive with some arduino, or just buy a bunch of remote-control-capable loads and control them from same place.

author: TiN
author_rank: Super Contributor
timestamp: April 23, 2018, 02:31:17 pm
content: I have made my old 12-channel 2KW ATX PSU testeropen-sourcewhile ago. It worked good for over 200 PSU tests before I sold it.
Any options for automotive grade SSDs for the small fish? - Page 1
Forum section: electronics / projects

author: magicmastja
author_rank: Contributor
timestamp: June 30, 2023, 05:57:37 am
content: Pretty much the title. Spent a long time working on a DIY infotainment board and getting (annoyingly) familiar with how small the high-performance AEC-Q100 part pool is for the startup/hobbyist dev audience. One of the last few part decisions I need to make is the main flash storage. It would really be nice to not have to constrain the design to eMMc bandwidths if I don't have to, as I do have 2 PCIe 2.0 lanes available in the current design.I suppose my questions are: 1. Infotainment seems to ride the line between Industrial and Automotive rating requirements given its position in the vehicle is less heat-intensive + less safety-critical, so is this a situation where Industrial rated M.2 SSDs from the likes of Apacer or Advantech could be satisfactory? Or 2. Any snowball chance in hell the likes of Micron or Silicon Motion would ever provide docs on their BGA SSDs to small manufacturers? lolEverything else in this board is automotive grade, and I've had to get creative with MPU and FPGA selection to make the feature set work at a not-insane price, but this seems like a tough wall to climb over.

author: Jeff eelcr
author_rank: Frequent Contributor
timestamp: July 02, 2023, 11:00:31 pm
content: It is not uncommon for OEMs to backorder repair parts with no ETA under warranty for some units nowadays.Jeff

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 03, 2023, 01:54:34 am
content: Just get a good quality M.2 drive and put a larger than usual heatsink on it.

author: sd
author_rank: Unknown
timestamp: July 03, 2023, 10:31:22 am
content: Swissbit has BGA PCIe SSDs for which they provide documentation, but as far as I know they're not automotive grade. Maybe drop them an e-mail?
Any PowerPC or Sparc device that is not that large? - Page 1
Forum section: electronics / projects

author: vuwabo
author_rank: Newbie
timestamp: April 11, 2019, 03:53:55 am
content: Hi.As title said, most of those servers are as big as a travel suitcase, and as heavy as 20kg or so, are there any device that is smaller and lighter? I know there are some routers use PowerPC, but they don't have video output.Thanks.

author: ejeffrey
author_rank: Super Contributor
timestamp: April 11, 2019, 04:34:50 am
content: An old macbook or a nintendo game cube would be an easy way to get a PowerPC in a portable form factor.There were a handful of sparc laptops made, I think they were somewhat popular in the oil and gas industry.

author: tooki
author_rank: Super Contributor
timestamp: April 11, 2019, 03:20:47 pm
content: An old G4 (PPC7400) Mac mini?What’s the use case?

author: james_s
author_rank: Super Contributor
timestamp: April 11, 2019, 03:56:13 pm
content: Sparcstation IPC, IPX, Classic and related models if you don't mind vintage.
Any projects in mind for DSBGA 1.6 x 0.861mm version of MCU MSPM0C1104 ? - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: March 12, 2025, 07:39:34 am
content: Saw that TI released MSPM0C1104 in 8-DSBGA at 1.6 x 0.861mm(24MHz Arm® Cortex®-M0+ MCU with 16KB flash, 1KB SRAM, 12-bit ADC, 5V tolerant io).Datasheet hereNot sure I have any need for a MCU that small, but damn it's impressive.

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: March 12, 2025, 03:35:35 pm
content: Yeah! Too tiny. You can try to use it in wearable projects.
Any Queen Fans Here? - Page 1
Forum section: electronics / projects

author: German_EE
author_rank: Super Contributor
timestamp: May 14, 2017, 09:01:39 am
content: Take a Queen fan, any Queen fan, and mention the 'Deacy Amplifier' and you'll probably get a smile. This audio amplifier was the key to the Queen sound and it was built from scrap parts by John Deacon, bass player in the band who was studying Electronics at the time. Well, now the full story can be told.http://hackaday.com/2017/05/08/a-queen-mystery-the-legend-of-the-deacy-amp/#more-255331Have fun

author: grumpydoc
author_rank: Super Contributor
timestamp: May 14, 2017, 09:12:18 am
content: Quote from: German_EE on May 14, 2017, 09:01:39 amI think Brian's "Red Special" made a pretty big contribution to the sound - especially his somewhat unconventional pickup wiring.

author: German_EE
author_rank: Super Contributor
timestamp: May 14, 2017, 10:05:43 am
content: Agreed, like a lot of things in life the Queen sound appears to be a series of happy coincidences.

author: Zero999
author_rank: Super Contributor
timestamp: May 14, 2017, 11:01:57 am
content: Quote from: German_EE on May 14, 2017, 09:01:39 amIt seems they have overlooked the speaker and acoustics of the amplifier, which would have been a very important part of the sound. It had a small wooden enclosure and the speaker was probably in very poor condition too, creating lots of distortion.

author: SeanB
author_rank: Super Contributor
timestamp: May 14, 2017, 11:58:25 am
content: Swear I have a similar supersonic amplifier sitting in a box somewhere, might be worth pulling it out and seeing it. Still have a Sinclair 12W kit, which may even work, seeing as it is a NOS unit, but with the rep they had for being made with the bin scrapings from Newmarket that probably is not too much to hope for.

author: chris_leyson
author_rank: Super Contributor
timestamp: May 14, 2017, 04:54:16 pm
content: Nice story, thanks man. I will run this past a guitarist friend of mine, he would love this stuff. The mismatched AC128s in the output stage would have produced a lot of second harmonic, exactly how much would be determined by the bias setting and the negative feedback from the tertiary winding on the output transformer to the driver emitter. Maybe with some Fourier analysis you could get a few clues as to how it sounds. Like the transformer feedback. Maybe only a few hundred mW into the speaker.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 14, 2017, 05:05:29 pm
content: Good stuff, and makes the point about electronic instruments as instruments, not perfect reproducers of sound. There is a place for both and they are often confused.

author: BradC
author_rank: Super Contributor
timestamp: May 14, 2017, 07:35:41 pm
content: Read the rest of the story of the reproduction. There'a a lot more to it than just the PCB.http://www.deacyamp.com/index.php?route=information/information&information_id=19