hybridfree/eevblog-posts huggingface dataset:
Open Source "Flying Squirrel" Tablet - Page 1
Forum section: electronics / projects

author: ricardo_mv
author_rank: Newbie
timestamp: October 31, 2013, 12:42:21 am
content: Hello everyone, i found this project to make an open source tablet (hardware and software) and i thought that Dave had to see it, give it's impressions and maybe lend it a hand. They are trying to make it modular (separated EOMA-68 cardhttp://rhombus-tech.net/allwinner_a10/news) so you can swap the CPU card for a better one when you want and keep the devicehttp://rhombus-tech.net/community_ideas/kde_tablet/news/. Also i think you can put this in the back of your tv a have an awesome media player (correct me if i'm wrong). They even have videos on youtube of the current state of developmentSorry about my English, not my native language.Best regards.
Open Source AlienTek DP100 Firmware - Page 1
Forum section: electronics / projects

author: seth.daniels
author_rank: Newbie
timestamp: November 28, 2024, 06:32:55 pm
content: Hello everyone,It seems like the Alientek DP100 runs off of a STM32F4 clone (AT32F415). Has anyone made an open-source firmware version of this? I know there’s lots of complaints about the UI despite the hardware being impressive for the price, so I’m curious if anyone has tried REing the FW in any way. I’m deciding whether or not to purchase one to do this myself…

author: coromonadalix
author_rank: Super Contributor
timestamp: November 29, 2024, 10:53:34 am
content: some eevblog threadhttps://www.eevblog.com/forum/testgear/dp100-mini-power-supply-(0-30v-0-5a)/theres othersgoogle searching this: alientek dp100 softwaregives some answers or some work, you may get luck there ?https://github.com/scottbez1/webdp100https://en.alientek.com/download.htmlhttps://github.com/jjcarrier/viconhttps://github.com/lessu/open_dp100https://blog.adafruit.com/2023/12/20/making-a-digital-power-supply-driver-and-gui-using-webhid/since there was cases of burning, failures and overshoot when you power them down, i'm not sure i would use them, at least on non sensitive stuff for sure
Free or Open Source Audio Modems - Page 1
Forum section: electronics / projects

author: SonicTheHog86
author_rank: Newbie
timestamp: May 01, 2018, 07:32:26 pm
content: Anyone know of any Free or open source audio modems? any that can use the I/O of a sound card, send/receive files and/or ASCII text, and hopefully has a reasonable baud rate.

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 02, 2018, 12:22:25 am
content: Look up "packet radio", which started as amateur radio operators sending data using radios designed for audio.
Open source DC Load project - 250W - Recommendations? - Page 1
Forum section: electronics / projects

author: killingtime
author_rank: Regular Contributor
timestamp: May 01, 2023, 08:49:41 am
content: Hi,Are there any open source DC load projects that people could recommend?Something tried and tested with a stable feedback loop, 250W or greater, 80v. CC mode. Remote sensing would be nice.I'm sure I remember seeing one like that on this board a while ago. Loads of effort was put into the design. Can't seem to find it using search.Found the project below but it's only 50W.https://www.eevblog.com/forum/oshw/arduino-programmable-constant-current-power-resistance-load/Thanks.

author: Shay
author_rank: Regular Contributor
timestamp: May 15, 2023, 01:45:46 pm
content: It's not hard to optimize a DC load for 250W, usually it is about using a higher SOA mosfet or putting a few in parallel.Adjusting the feedback loop might be needed if you place more mosfets in parallel, because you add the gate capacitance, in which the op amp has to deal with the additional capacitance.As a starting point look for Jay_Diddy_B dc load:https://www.eevblog.com/forum/projects/dynamic-electronic-load-project/

author: globoy
author_rank: Frequent Contributor
timestamp: May 15, 2023, 02:41:48 pm
content: I can't vouch for it but this guy is selling a PCB for a load that almost meets your needs (180-240W):https://www.tindie.com/products/fivefishaudio/180w-240watt-electronic-load-pcb/And the design lives in the assembly document here:https://www.fivefishaudio.com/pdf/EloadAssemblyGuide.pdfThe document specifies with an upgraded pair of MOSFETs it can do 120V @ 2A (for 30 minutes).

author: temperance
author_rank: Super Contributor
timestamp: May 15, 2023, 04:00:36 pm
content: Yet an other completely wrong designed dummy load circuit.-Improper drive circuit= a nice oscillator-No compensation for inductance caused by test leads.-The use of blue printed circuit boards to hide your incompetence.But probably good enough for frying fish.
Open-source firmware for chinese Geiger counter/radiation meter (FS2011) - Page 1
Forum section: electronics / projects

author: Gissio
author_rank: Newbie
timestamp: April 10, 2023, 03:04:47 pm
content: Hello everyone.I have recently released an open-source firmware for replacing the firmware of some chinese Geiger counters/radiation meters (FS2011). The firmware is available athttps://github.com/Gissio/fs2011pro.Some features:* Instantaneous rate, average rate, dose, and history modes.* Intuitive user interface for easy navigation.* Measurements in Sievert, rem, cpm and cps.* Multiple history periods, including 2-minute, 10-minute, 1-hour, 6-hour and 24-hour options.* 95% confidence intervals to ensure accurate readings.* Measurement hold for instantaneous rate, average rate, and dose.* Overload alert to prevent damage to the device.* Customizable rate and dose alarms for personalized use.* Configurable pulse click sounds: off, quiet, loud.* Configurable backlight timer: off, on for 10 seconds, on for 60 seconds, or always on.* Configurable battery type for battery level monitoring.* Configurable Geiger-Müller tube: HH614 (48 mm long), M4011 (105 mm long), SI-3BG (5 mm long).* Device life statistics for monitoring usage.* 40% more battery life compared to the original firmware.* Power-on self-test and safety watchdog.* Nuclear chess.Hope you find it useful.

author: MarkS
author_rank: Unknown
timestamp: April 10, 2023, 03:15:35 pm
content: Please don't cross post.https://www.eevblog.com/forum/beginners/welcome/

author: Gissio
author_rank: Newbie
timestamp: April 10, 2023, 05:24:27 pm
content: My apologies. I've deleted the other message.
Open-source friendly PCIE-SATA bridge - Page 1
Forum section: electronics / projects

author: avishorp
author_rank: Newbie
timestamp: January 24, 2021, 07:32:32 am
content: I'm looking for a way to add SATA to my open source design. I have PCIE and I need a chip that implements a SATA interface. Apparently, most designs use chips by JMicron, for which public datasheets and ref designs are unavailable. Their chips are also not stocked by distributors such as Digikey and Mouser. Are there any other good options?

author: LeonR
author_rank: Regular Contributor
timestamp: January 29, 2021, 03:33:11 pm
content: Marvell and ASMedia also make those. Don't know about documentation availability, though.
Open Source Multimeter, $10 of parts - Page 1
Forum section: electronics / projects

author: GilbouFR
author_rank: Contributor
timestamp: June 21, 2019, 07:10:50 am
content: http://embedblog.eu/?p=298

author: coromonadalix
author_rank: Super Contributor
timestamp: June 21, 2019, 08:39:32 am
content: You should write, it was talked on hackaday too ...

author: Miyuki
author_rank: Frequent Contributor
timestamp: June 21, 2019, 10:20:12 am
content: Nice one.I also want to build one like this, but always is something more important
Open Source Oscilloscope for the Arduino Community - Page 1
Forum section: electronics / projects

author: USB_Guru
author_rank: Newbie
timestamp: May 06, 2015, 07:11:56 am
content: Please support our Kickstarter Campaign: UnoProLogic2 – Ultra Low Cost Open Source Oscilloscope by Earth People Technologyhttp://kck.st/1Fi0E1OIt is an inexpensive <$30 4 channel oscilloscope with 300K Sample rate. The Hardware is kept simple with PC software doing all the heavy lifting.

author: miguelvp
author_rank: Super Contributor
timestamp: May 06, 2015, 07:16:34 am
content: Just FYI crowd funding projects go here:https://www.eevblog.com/forum/crowd-funded-projects/Open Source ones (usually non crowd funded ones) go here:https://www.eevblog.com/forum/oshw/Btw, it looks cool.
Open Source Temperature Candle Night Light - Page 1
Forum section: electronics / projects

author: hardsoft
author_rank: Newbie
timestamp: January 29, 2012, 11:09:46 pm
content: My extreme paranoia about SIDS helped lead me to work on this project after my daughter was born, and I finally got around to putting up the design information. It's open source and all the design details are posted herehttp://www.mermardesigns.com/temp_candle.htmIt was a simple but fun project that if anything was an excuse to finally use an 8-pin micro!

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: January 30, 2012, 10:21:14 am
content: I was so scared from SIDS i did not sleep first three months and just watched her. But to my knowledge SIDS is more about Asphyxia than ambiental temperature ( i was told so by my child doctor). However a nice project!

author: hardsoft
author_rank: Newbie
timestamp: January 30, 2012, 12:26:07 pm
content: QuoteI was pretty much the same way. I was thinking about an accelerometer based project to help detect when the baby rolled over to account for your asphyxia point. I know rates have gone way done since they started recommending putting sleeping babies on their backs.

author: cybergibbons
author_rank: Frequent Contributor
timestamp: January 30, 2012, 03:07:09 pm
content: Nice little project! I have something very similar - a wireless node measures temperature in the babies room and can be viewed on a webpage. I want it to remotely control the heating in the room, but that is a work in progress as I need to reverse engineer the wireless signal to control it.There are so many myths about SIDS, it is crazy. In the UK we don't count deaths with an obvious source of asphyxia as SIDS - SIDS is only diagnosed by excluding pretty much everything else. Not to say that it isn't important to avoid asphyxia though. It's incredibly hard to isolate the factors that cause SIDS.
Open source TIG welder logic controller - Page 1
Forum section: electronics / projects

author: robby60259
author_rank: Newbie
timestamp: December 15, 2023, 04:15:01 am
content: Hello, I am building a welder and I need a circuit that can provide a control signal to adjust the frequency and balance (duty cycle) of the output. I would like to use an Arduino Uno if possible to control these two functions via two potentiometers. I need help with the code. I would prefer the frequency to be adjustable from approximately 50Hz to maybe 200Hz and the duty cycle around 20% to 80%. The values only need to be an approximation, the higher frequency helps with arc control, and the variable duty cycle helps with cleaning and penetration when welding aluminum. This sketch is as far as I have got. Am I going in the right direction? Any help would be greatly appreciated.byte oscOut = 3 ;int pot1 = A0;int pot2 = A1;void setup(){pinMode(oscOut, OUTPUT);pinMode(pot1, INPUT);pinMode(pot2,INPUT);}void loop(){analogRead(pot1);analogRead(pot2);OCR2A = (analogRead(pot1)-380); // defines the frequency 51 = 38.4 KHz, 54 = 36.2KHz, 58 = 34 KHz, 62 = 32 KHzOCR2B = ((analogRead(pot2)-380)/2); // defines the duty cycle - Half the OCR2A valuefor 50%TCCR2A = _BV(COM2B1) | _BV(WGM21) | _BV(WGM20);TCCR2B = _BV(WGM22) | _BV(CS21);}
Open source tiny battery management module I made - Page 1
Forum section: electronics / projects

author: Erik_EDr_Tech
author_rank: Newbie
timestamp: November 22, 2024, 04:46:57 pm
content: Hello people! This is an open-source power management module I made to speed up hardware development; most of the stuff I do is battery-powered, and there was always that tedious part of the project in which a power management/battery handling system has to be thought out, connected together and redrawn for each PCB.I made this module to be a drop-in solution to that problem, with a bunch of features like 4+16 ADC channels, current measurement, on/off behavior handling, temperature sensing, 2A charger, and a few other thingies. It's all running on ATtiny1616.On top of it all, the demo board has a convenient switch to switch between ATtiny1616 UPDI for programming and serial for communication through the USB port, this makes it easy and fast to debug through serial (in case you're not using microchip original software to program).Would love to hear your thoughts and suggestions.Anyways, if you want to check out my (very) detailed documentation, you can do so here:https://github.com/EDrTech/bATtiny-Guard-PMG001
Open sourcing my microcontroller design (pics inside) - Page 1
Forum section: electronics / projects

author: nudge
author_rank: Contributor
timestamp: December 04, 2016, 05:51:59 pm
content: Hey all!Long time lurker, I reckon its about time I contribute back to the communityAnyways, I am thinking of open sourcing a microcontroller board that I designed about a year ago. What is the preferred format for open source hardware these days? EAGLE, KiCad, CircuitMaker, etc? The board was originally designed in Altium Designer. This might be a good exercise to start playing around with some other tools. Not sure how difficult it is to export/import designs but might give it a shot -- worst case i'll just open up the Altium design files.The MCU board is based on a Texas Instruments Piccolo F28069 which is a great little chip. Its zippy (90MHz + FPU and CLA co-processor) and has lots of control oriented peripherals (fast PWMs and ADCs) and has 256KB Flash, 100KB RAM and a USB interface. The original design was for a power converter, but maybe someone will find use for it too.A cool aspect about this board is that it integrates a USB->JTAG bridge using a FTDI FT2232H which emulates a XDS100 Ver 2.0, so it is possible to program the micro directly via USBHere's some pictures:Cheers,David

author: ebclr
author_rank: Super Contributor
timestamp: December 05, 2016, 01:42:33 am
content: A similar board ready top use for 24.99 USDhttps://store.ti.com/LAUNCHXL-F28069M-InstaSPIN-MOTION-and-InstaSPIN-FOC-enabled-C2000-Piccolo-LaunchPad-P50823.aspx

author: diyaudio
author_rank: Frequent Contributor
timestamp: December 12, 2016, 02:17:08 pm
content: I really wish companies would make smaller dev boards like these and just drop the ISP section to reduce cost, even though its mandatory they could just sell it as a separate pcb/unit.

author: JoeN
author_rank: Frequent Contributor
timestamp: December 12, 2016, 02:29:59 pm
content: Nice board. 4 layer? Where did you have it manufactured? What were the design rules for vias and traces? Also, why the big crystal for USB and a more modern one for the microcontroller?
Open University Power Supply-Meter Kit HK/1A - Page 1
Forum section: electronics / projects

author: NottheDan
author_rank: Frequent Contributor
timestamp: May 22, 2022, 12:38:55 am
content: This device was made in the 1970s for the Open University T100 "The Man-Made World" course.I know it is a long shot, but does anyone here know more about this thing? Have documentation or a schematic they can share? I'd like to put mine in a working condition.Also, what size are the sockets? 2mm banana plugs don't fit.

author: IanB
author_rank: Super Contributor
timestamp: May 22, 2022, 02:47:38 am
content: It doesn't seem all that sophisticated. It is an adjustable power supply and a (presumably) separate volt/ammeter in a single box.To get a circuit diagram you could open it up and reverse engineer it.Also, to test the meter portion, you could try various voltages and currents with the unit unplugged. Most likely the meter does not require power to work.Be careful not to overload the meter with more than 50 mA though, or you could damage it.

author: NottheDan
author_rank: Frequent Contributor
timestamp: May 22, 2022, 06:57:19 pm
content: Quote from: IanB on May 22, 2022, 02:47:38 amYes, a linear adjustable power supply executed in ten transistors, and the meter is separate.Quote from: IanB on May 22, 2022, 02:47:38 amI just don't trust myself not to fuck it up without some documentation for reference. And there's the off chance that someone here knows something about it.Quote from: IanB on May 22, 2022, 02:47:38 amCheers.

author: aneevuser
author_rank: Frequent Contributor
timestamp: May 23, 2022, 06:29:59 pm
content: Have you tried contacting the OU? The main electronics guy there was David Crecraft, I believe, and I doubt that he's still in situ, but they may have contact details for him.

author: Terry Bites
author_rank: Super Contributor
timestamp: May 24, 2022, 02:42:26 pm
content: Use drill bits to determine the size of the jacks.Buy the kit! You never know the schematic might even be in the box. Contact seller and make him an offer for a scan.https://www.ebay.co.uk/itm/154964335411?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338686281&customid=sterlingxs&toolid=10050

author: themadhippy
author_rank: Super Contributor
timestamp: May 24, 2022, 02:50:15 pm
content: Quotei'd be surprised if the seller and op aint one and the same

author: NottheDan
author_rank: Frequent Contributor
timestamp: May 29, 2022, 11:56:05 pm
content: Quote from: aneevuser on May 23, 2022, 06:29:59 pmNope. Didn't even think about that until you mentioned it. Now trying to find a contact, don't think student or media enquiries would go to the right person.Quote from: Terry Bites on May 24, 2022, 02:42:26 pmDammit, and now I can't find my drill bits.Quote from: Terry Bites on May 24, 2022, 02:42:26 pmI know. There isn't.Quote from: themadhippy on May 24, 2022, 02:50:15 pmThen be surprised. That's merely the seller I bought mine from.
OpenBoardView - Page 1
Forum section: electronics / projects

author: Cujo
author_rank: Regular Contributor
timestamp: June 08, 2019, 08:53:26 am
content: Is there a place to get schematics for OpenBoardView ?

author: thinkfat
author_rank: Unknown
timestamp: June 08, 2019, 01:36:34 pm
content: Google. Seriously.Gesendet von meinem Nokia 6.1 mit Tapatalk

author: MarkF
author_rank: Super Contributor
timestamp: June 08, 2019, 08:25:34 pm
content: Only if the original poster of the BRD (PCB board) file also posted the corresponding SCH (schematic) file.The normal development flow is to create a PCB layout from a schematic.This is pretty much a one way process. I'm not sure there is enough information in the BRD file to go back.I don't know of any tools that let you get back to a schematic from the PCB layout.
openEMS - Blender Video Guide - Rotman Lens - Page 1
Forum section: electronics / projects

author: Schottky
author_rank: Regular Contributor
timestamp: June 22, 2024, 09:02:08 pm
content: Hi everyone, I've been asked many times to create a video tutorial/guide on how to use Blender for openEMS simulations. And so I have now created a video on YouTube. The video will show you to first create geometries and specify ports, export them to openEMS as STL files, writing a few python scripts to export port coordinates and data from paraview, and then using geometry nodes to visualise and animate the results back in Blender.The video is based on the Rotman lens animation I did previously shown herehttps://www.eevblog.com/forum/projects/electromagnetic-simulations-renders-with-openems-blender/msg5542239/#msg5542239as the workflow for it covers a wide range of topics. I hope you find this video informative.
Home automation - openHAB vs Node-Red? - Page 1
Forum section: electronics / projects

author: Geoff
author_rank: Contributor
timestamp: December 17, 2016, 03:49:08 am
content: How does openHAB compared to using Node-Red for home automation or is this the wrong question?I am still getting my head around implementing some home automation (some lights and usual weather type stuff) using openHAB, then I went to a presentation on Node-Red, now I'm confused as to which to use.If you familiar with both openHAB and Node-Red, could you please let me know how they relate?
OpenSCAD and 3D rendering - Page 1
Forum section: electronics / projects

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 17, 2021, 08:31:40 pm
content: I often use OpenSCAD, primarily to design enclosures.https://openscad.org/It can generate STL files, which is good for 3D printing, for instance. But as far as graphics rendering goes, the internal 3D renderer is pretty crude. It's OK for designing, but something nicer looking could be good for illustration/documentation purposes.So, does anyone know of any means to make pretty 3D renderings from either OpenSCAD files, or STL files?

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 18, 2021, 04:16:00 pm
content: Blenderlooks like an option, as it can import STL. I tried and it's able to import my STL files with no issue. Problem now, Blender seems to have a rather steep learning curve. I have a pretty hard time figuring out how to setup a proper render scene. I guess I'll have a bit to read...If anyone knows of another option, I'm all ears.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 22, 2021, 06:11:15 pm
content: So, looks like this didn't spark much interest. Or maybe another section would have been more appropriate - if so, a moderator can feel free to move it elsewhere.Anyway, Blender is definitely too much for me. I have a hard time doing even simple renderings. It takes too much time. I'm sure it's very powerful as some people do amazing stuff with Blender... but at this point, it doesn't seem to be for me.I'm more familiar with POVRay. So I found a tool called stl2pov, to translate STL files to POVRay meshes.Basically two variants of this tool exist: a C one, and a Python one.https://github.com/Spiritdude/stl2povhttps://rsmith.home.xs4all.nl/software/py-stl-stl2pov.htmlThe Python one is supposed to be better and faster, but it yields an error on my STL files. I'm not good enough with Python to fix this. Maybe someone who is and would be interested could have a look.The C version works for me, although it is slowish for large STL files, and sometimes generates a few "empty" triangles at the end of the meshes. I'll have a look at this. Meanwhile, I removed them manually.For anyone curious, I'll attach a render of an enclosure I designed lately with OpenSCAD. Don't hesitate to comment or chime in if you're interested in using/or helping with the stl2pov tool(s).
OpenSource ESR Meter Help Needed - Page 1
Forum section: electronics / projects

author: bseishen
author_rank: Contributor
timestamp: April 09, 2013, 08:02:33 pm
content: Currently working on creating a open ESR meter. I am using Dr Lee Hung's meter as the basis of my design.http://members.upc.hu/lethanh.hung/LCFESRmero/en/LCFesR_4_eng.pdfI have also used the code from this form to get me up and going.http://arduino.cc/forum/index.php/topic,80357.0.html Currently my measurements are way off. I have a feeling that the Shottky diode Vf vs current going through should play into the calculation. I have attached a schematic of my current PCB. If someone could point me in the right direction on figuring out the formula it would be greatly appreciated!

author: bseishen
author_rank: Contributor
timestamp: April 10, 2013, 03:29:38 pm
content: Here is my current ESR measurement routine if it helps any!Code:#define DISCHARGE_PORTPORTB#define DISCHARGE_PINPB2#define LO_PULSE_PORTPORTB#define LO_PULSE_PINPB1#define LO_VIN_MV4700#define HI_PULSE_PORTPORTB#defineHI_PULSE_PINPB4#define HI_VIN_MV4550#define ADC_CHANNEL0#define R_PULSE_OHM100#define R_LO_PULSE_OHM1000#define V_REF1.1float getESR(){unsigned long accumulator = 0;unsigned int sample = 0;float Rm;int i = 0;while ( i++ < 4096 ){DISCHARGE_PORT|=_BV(DISCHARGE_PIN);_delay_us( 600 );DISCHARGE_PORT&=~_BV(DISCHARGE_PIN);HI_PULSE_PORT&=~_BV(HI_PULSE_PIN);_delay_us(5);sample = ReadADC(ADC_CHANNEL);HI_PULSE_PORT|=_BV(HI_PULSE_PIN);accumulator += sample;i++;}esrSamples = accumulator >> 6; // decimate the accumulated result// sampling is done// calculate voltage on AIN0 pin...milliVolts = (esrSamples * V_REF) / 65.536;// calculate ESR in milliOhmsR2=R1/((vin/vout)-1)Rm = (R_PULSE_OHM / ((HI_VIN_MV / milliVolts) - 1)) * 1000;return Rm;}
Opensource high Current Super Cap Welder - Page 1
Forum section: electronics / projects

author: mrpackethead
author_rank: Super Contributor
timestamp: September 30, 2023, 05:42:47 am
content: Just kicking this over in my mind at the moment. I need a really decent Spot Welder for batterys.. ( 1000's of them ).. Yes, i know it would be less effort and probably cost less just to buy one. But where would the fun be in that.

author: p.larner
author_rank: Frequent Contributor
timestamp: October 01, 2023, 08:50:32 am
content: and so what is the point of this post?,seems it lacks context.
Operating a high frequency transformer "out of specs" - Page 1
Forum section: electronics / projects

author: kratikus
author_rank: Newbie
timestamp: March 29, 2023, 07:31:28 pm
content: Hello there,This is my first post in here.I am currently working on a non-isolated high-voltage (1kV) low-current (0.5mA) flyback converter, which steps its input voltage (24V) to around 500V, and with the help of a voltage doubler at the output, it would reach 1kV.The output voltage should also be adjustable from around 50V to 1kV.Since I would like to avoid having another custom made transformer, I was looking into using the following transformer:https://www.we-online.com/components/products/datasheet/7491181012.pdfBelow are its specs:Vin: 85 - 265VACVo: 12VIo: 250mANsp: 8.1Isec = 250mA / 8.1 = 31mASince the transformer secondary would see around 500Vpeak it would obviously be out of spec, however, I was thinking whether it could still withstand this higher voltage as the current in question (0.5mA) would be much lower than what the transformer can tolerate. Furthermore, from a clearance and creepage perspective, it should provide more than enough isolation.I also do not know whether the higher voltage-per-turn ratio could be potentially damage the wire isolation.Is this assumption correct, or is there something else that I am missing?Thanks

author: Weston
author_rank: Regular Contributor
timestamp: March 29, 2023, 09:29:47 pm
content: I think the datasheet is implying that it would be used in a flyback converter with those specifications.The peak voltages seen across the winding would be sqrt(2)*265 = 374V and -12*8.1 = -97V. Thats 471V p-p. It does not seem too far off from your 500V.Some insulation stress is driven by dv/dt. Due to the leakage inductance the dv/dt will be lower when the high voltage winding is used as a secondary.The primary to secondary insulation is most likely going to be fine, as this is for off-line use. Such transformers from reputable suppliers are typically pretty overbuilt. At some point you have to worry about corona causing long term degradation.This seems close enough where it would work. As a one/few I would expect it to work without issue. The biggest concern would be if the start and end of the wire on the HV side overlap. Buying one transformer and taking it apart would tell you a lot.
operation of comparator  with one of the input is pot?  - Page 1
Forum section: electronics / projects

author: terra
author_rank: Newbie
timestamp: March 23, 2014, 04:15:06 pm
content: hioperation of comparator with one of the input is pot?

author: dumle29
author_rank: Regular Contributor
timestamp: March 23, 2014, 05:02:41 pm
content: If it's marijuana I don't know. If its a Potentiometer set up as a voltage devider, it will work as an op amp works.It will adjust it's output so that the two inputs are the same.

author: pickle9000
author_rank: Super Contributor
timestamp: March 23, 2014, 05:10:12 pm
content: @dumle29 "If it's marijuana I don't know"Magic smoke perhaps?Sorry I couldn't resist.

author: Pillager
author_rank: Unknown
timestamp: March 23, 2014, 05:45:33 pm
content: Quote from: pickle9000 on March 23, 2014, 05:10:12 pmNiceQuote from: dumle29 on March 23, 2014, 05:02:41 pmOnly if you have a feedback resistor. Otherwise, the opamp input won't "know" what the output is doing.Here is a nice page that should help:http://www.allaboutcircuits.com/vol_6/chpt_6/2.html

author: SArepairman
author_rank: Frequent Contributor
timestamp: March 23, 2014, 06:34:56 pm
content: well it depends how much pot. if you use to much your probably gonna wire it wrong and blow something out.I would just stay stick with LM324 or something cheap, especially if there is alot of pot

author: GreyWoolfe
author_rank: Unknown
timestamp: March 24, 2014, 03:36:19 pm
content: I think that if there is a lot of pot involved, forget the circuit and concentrate on brownies, twinkies and other favorite munchies.

author: SeanB
author_rank: Super Contributor
timestamp: March 24, 2014, 06:54:42 pm
content: If I want some then I just have to go outside and look for the weeds then. It grows pretty close to wild here, I am always pulling the little bushes out and tossing them away. Neighbour had a 5m high tree that we chopped down the day before the garden services guys came round. They were not impressed, especially as we burnt the whole bush, keeping upwind of the smoke.

author: dannyf
author_rank: Super Contributor
timestamp: March 24, 2014, 09:02:08 pm
content: - operation of comparator with one of the input is pot? -The output would go high, very high.

author: fretless
author_rank: Contributor
timestamp: March 24, 2014, 09:53:55 pm
content: Quote from: dannyf on March 24, 2014, 09:02:08 pmDING DING DING!We have a winner!
operational amplifier power - Page 1
Forum section: electronics / projects

author: bigendian
author_rank: Regular Contributor
timestamp: April 01, 2025, 02:45:44 pm
content: Hi,have some issues in a board, the +PVDD of a AD8065ADZ (+16V) is actually missing (faulty PS i removed), while the -PVSS (-16) is there. Can i damage the op amp in this way ?thanks

author: TimFox
author_rank: Super Contributor
timestamp: April 01, 2025, 03:23:20 pm
content: With a split supply, an open circuit (or high resistance) to one of the two power pins may cause the device to latch up and draw excessive current from the other power supply, overheating the IC.

author: magic
author_rank: Super Contributor
timestamp: April 01, 2025, 06:24:47 pm
content: Generally, taking any pin outside supply rails can cause problems in ICs, unless there is enough external resistance on each connected pin to limit current to safe level.If you disconnect the positive rail, the chip will discharge it below ground. If some pins are connected to ground, they are outside the rails now.That being said, I have probably done it many times with various opamps, no magic smoke so far. But YMMV.

author: bigendian
author_rank: Regular Contributor
timestamp: April 01, 2025, 07:00:14 pm
content: thanks a lot
opinion needed (li-ion series charging – equalising – overvoltage protection) - Page 1
Forum section: electronics / projects

author: leonidas77
author_rank: Newbie
timestamp: November 07, 2020, 04:01:01 pm
content: Last weeks I ve been looking on series li-ion balancing circuits out there for a project I had in mind a topology behaving like a zener connected in parallel with each cell with a voltage knee around 4V and a transition from 0A@4V to say 1A@4.01VThe greatest problem was the temperature coefficient which had to be around 10mV for 40oC temperature swings.Last days I started getting results and by combining subcircuits with different but tunable tempcos.The circuit lives in Ltspice simulations only but I used active components for which I verified that Ltspice gives correct tempco behavior (for example an IRF6620 as the power MOSFET).It is fully tunable and predictable as of knee voltage and tempco (you can modify tempco from negative to positive by changing a single resistor)I have not run a sensitivity analysis yet but I guess that with low tempco resistors the behavior will not change much and with random resistor variation I hope the circuit will remain to specsI give you the IV characteristic(current axis is log scale) Blue trace is at 0oC and red trace is at +40oCWhat is your opinion on the result? Does it worth pursuing the idea?As I am quite old now and not affiliated with any university professors what is the best way to have the circuit peer reviewed? Could you please recommend a Journal?My job is physics teacher in a secondary school and I had an msc in microelectronics in the past but I am a little afraid to publish this. The most probable thing is that either the achievement is not important (if you know other circuits please point them to me) or other unforeseen problems of my idea. On the other hand it would be a same to not let other people use this idea if it is good.The idea will probably have usability also in the field of I-V references and not only on charging series lion batteriesThank you!
Opinion on Layout Example - Page 1
Forum section: electronics / projects

author: mrburnzie
author_rank: Regular Contributor
timestamp: December 21, 2022, 10:48:06 am
content: Hi!I'm looking to use TPS562200DDCR.The example layout is quite an interesting one and I would like to get comments on it from experienced pcb designers.What do you think about the SW node routed on the other layer as well?Datasheet:https://www.ti.com/lit/ds/symlink/tps563200.pdf?ts=1671536497284Page: 24

author: tszaboo
author_rank: Super Contributor
timestamp: December 21, 2022, 12:00:55 pm
content: It doesn't look particularly good. I would probably move the bypass caps south of the IC, and route GND below it. I also don't understand the VFB routing. I think the layout is made for 2L boards, where the EMC considerations are not important. Look at the EVM. Those loops are gigantic, and even the inductor is oversized. Strange, because the IC isn't really old tech.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 21, 2022, 02:36:07 pm
content: Indeed. I would have expected the shortest path between SW and the output inductor, as mentioned even on the app note listed on the product's page (check section 3)https://www.ti.com/lit/an/slva922/slva922.pdfThe GND under the device might not be as wide as they claim on the same document above, but being 2A that shouldn't be too hard to achieve.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 21, 2022, 04:58:59 pm
content: Better like this:The inductor can be adjacent so the SW node has basically zero size, and the bootstrap cap is a small trace sneaking around just below.The ground doesn't even need to flow under the chip, fine to use a couple more vias to do the same thing and then SW can go under the chip to BS without any vias on SW.Note they recommend inner layer, i.e. this is a 4+ layer layout. So you can have inner/bottom copper covering (surrounding) the switch node with ground pour, so it doesn't expose any emissions. I don't mind having fair sized pours like that, as long as nothing else needs inner-1 in the area of course. Which, you'll usually be putting this in a PSU section by itself, so that's fine, but be careful on high density builds.Tim
Opinions on FPCAP's  (Polymer Aluminum Solid Electrolytic Caps) - Page 1
Forum section: electronics / projects

author: jlmoon
author_rank: Unknown
timestamp: April 02, 2015, 04:49:17 pm
content: Greetings,Looking for opinions on the new fangled Polymer Aluminum Caps.Anyone have failure analysis or other test results over time?Will they hold up well in SMPS and such?JLM
Optical Density measurement Ideas? - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: March 04, 2018, 02:12:34 pm
content: Hi,I was wondering if it's possible to measure Optical Density with these Color sensors, like ISL29125? is it possible? what's the formula to convert the reading to OD? any other ideas are welcome

author: Kleinstein
author_rank: Super Contributor
timestamp: March 04, 2018, 04:29:28 pm
content: To measure optical density it still needs a light source and some optics. As most light sources are not that stable it may take a way to switch between the sample and a transparent light path. With lower accuracy an LED might be considered stable enough over a short time (e.g. a few minutes).In photography OD is defines as log_10 of the intensity ratio due to absorption.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: March 05, 2018, 06:58:37 am
content: Thanks, So How should I calculate intensity? Should I use this formula to calculate the intensity? intensity =SQRT((R^2+G^2+B^2 ))

author: jprozas
author_rank: Newbie
timestamp: March 05, 2018, 11:25:32 pm
content: Luminance YY = R*0.3+G*0.59+B*0.11https://www.scantips.com/lumin.html

author: ammjy
author_rank: Regular Contributor
timestamp: March 05, 2018, 11:44:25 pm
content: might be, it will help to you ?for measure fluide level. i used photodiode and LED light.(elementry class !! haha)in result. most big problem was the control variables of materials ( for example, Light reflection of material, surface of material things.. )(actually i didnt calculate.)in pictures. for fluid sample. i used coke.(it was bad choice)character of photodiode really well reciving effect from temp..LED temp is really hot.

author: texaspyro
author_rank: Super Contributor
timestamp: March 06, 2018, 02:00:58 am
content: Most OD measurements and devices require a very large dynamic range (>20 bits is not unusual) and most color sensors do not come close to being able to do that.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: March 06, 2018, 06:58:43 am
content: Thanks for the updates,QuoteThe new ones have 16bit's of Res, But do you happne to know what devices they use that have more than 20bit?

author: ajb
author_rank: Super Contributor
timestamp: March 06, 2018, 03:11:55 pm
content: What range of OD do you want to measure? If you want a range of three steps, that's a ratiometric range of 1000, so ten bits right there, assuming your sensor is linear. You'll need ~3.3 bits per OD step just to have the dynamic range.

author: texaspyro
author_rank: Super Contributor
timestamp: March 06, 2018, 06:14:28 pm
content: Quote from: ali_asadzadeh on March 06, 2018, 06:58:43 amThe high dynamic range / lab quality units don't use integrated color sensors. They use individual light sensors and ADC chips.
optical encoder output. - Page 1
Forum section: electronics / projects

author: drm
author_rank: Contributor
timestamp: October 21, 2013, 03:11:18 pm
content: Hi all.I am trying to convert a DC motor, into a servo.Heres a playlist, with videos showing project from begining up today:goo.gl/ha5f1cNeed help to know if my signal from this OP AMP comparator, is able to be detectedwithout errors from a PIC.Or must to make it look better, with a schmitt trigger .

author: awallin
author_rank: Frequent Contributor
timestamp: October 21, 2013, 04:48:58 pm
content: A comparator or schmidt trigger that gives clean edges and stable 0V/5V logic levels is a good idea.If you are building your own encoder then think about what the maximum rpm you want. With a high encoder count (like 1000 ppr) and a high rpm the encoder must have MHz bandwidth.The PICs that are meant for motor control usually have dedicated hardware quadrature encoder inputs. This is much easier and more robust than trying to read the encoder in software with an interrupt or similar.If you need to know which direction the motor is turning you need two signals in "quadrature" i.e. shifted 90-degrees from eachother.In addition optical encoders usually have an index-output which goes high (or low..) once per revolution - it is useful for e.g. homing in CNC applications.

author: drm
author_rank: Contributor
timestamp: October 23, 2013, 03:20:17 pm
content: Ok Awallin, thanks for your reply.Already added video to playlist, where bouncing is obvious sampling at 200khz.(switch to HD)

author: drm
author_rank: Contributor
timestamp: October 23, 2013, 03:59:04 pm
content: Capturing from locked rotor, to hundreds of revolutions.

author: drm
author_rank: Contributor
timestamp: October 24, 2013, 06:04:42 pm
content: Channel 0 Looks better now adding STWill run motor at 3000 rpm to see how it works....
optical encoder to spi static position? - Page 1
Forum section: electronics / projects

author: iceisfun
author_rank: Regular Contributor
timestamp: September 17, 2013, 03:31:36 pm
content: I want to setup a PIC to read a few optical encoders and return their real position, also to "zero" them via SPI.My plan is to use a small PIC, track the wheel positions internally with interrupts and push the data over SPI as necessary to keep all my encoding wheels data available at need.Is there a easier way to go about this or am I on the right track?

author: Zbig
author_rank: Frequent Contributor
timestamp: September 17, 2013, 04:50:19 pm
content: Hmm, not sure what your actual question / dilemma is but basically what you get from the quadrature encoder is two phase-shifted square signals and from their phase (or sequence of their transitions) you deduce the direction of the rotation. There's no absolute position information - it's up to you to keep track by counting each "step" so there's also no "zeroing" as such as the "zero" position is where and when your software decides it to be. You can think of the encoder as a replacement for UP / DOWN buttons in that respect. And sure, you can dedicate an MCU for the purpose of encoder tracking but this could just as well be handled by your main application MCU in most situations.

author: dannyf
author_rank: Super Contributor
timestamp: September 17, 2013, 07:31:11 pm
content: QuoteThat's fairly easy:1) write a piece of code that reads the encoder;2) write a spi slave;3) read the spi slave to see if you should reset the counter in the encoder routine;4) put them together;Done.
Optical Mouse as Arduino Web Camera - Page 1
Forum section: electronics / projects

author: frenky
author_rank: Unknown
timestamp: December 05, 2013, 03:47:29 pm
content: Hi guys.I made this tutorial on how to convert optical mouse into web camera:http://frenki.net/2013/12/convert-optical-mouse-into-arduino-web-camera/It only has 15x15 resolution and slow framerate but it could be used in robot vision I guess.The more usefull part is how to stream data from arduino into web browser with socket.io.Short demo:Have fun

author: zapta
author_rank: Super Contributor
timestamp: December 06, 2013, 02:20:47 am
content: Very nice.IIRC this chips have very high rate fps (600?). We used them once for indoor localization. You put them face down toward the floor and measure x and y movement.

author: Mysion
author_rank: Regular Contributor
timestamp: December 14, 2013, 02:27:43 am
content: Wow that's a pretty neat project!Is there any way to get one of those sensors short of tearing apart mice?

author: Tinkerer
author_rank: Frequent Contributor
timestamp: December 14, 2013, 04:02:19 am
content: Quote from: Mysion on December 14, 2013, 02:27:43 amThe chip is a ADNS-5020-EN. Or at least the last version I found in one of my mice. Could have changed to a updated part by now though, but I am sure its pretty similiar still even if it has.

author: amyk
author_rank: Super Contributor
timestamp: December 14, 2013, 11:33:53 am
content: A quick search shows Digikey andMouser () used to sell them, and a few other sites have them in stock too, as well as later versions.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 14, 2013, 02:32:00 pm
content: I remember a project where someone tapped off some lines in an optical mouse to a parallel port in order to make it double as a barcode scanner.
optical semiconductor junction measurement time constants. - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: September 25, 2018, 08:25:54 pm
content: How do they determine safe operating area?I assume they have some kind of modified part that they measure with a IR thermometer?It seems like it would make a slightly faster feedback mechanism for over load disconnection. It's time constant would be alot faster then the heat sink.Fets:I have a little germanium window. Any idea what a good transistor to look at might be?

author: David Hess
author_rank: Super Contributor
timestamp: September 26, 2018, 02:12:58 am
content: Some old Motorola application notes discuss their characterization of bipolar transistors where they simply test a representative sample to destruction and assign safety margins. They also specifically warn that testing transistors this way may damage them even if they pass so it is not appropriate to test every transistor.PN junction temperature can be roughly measured through its negative temperature coefficient but of course this only applies where there is access to PN junction and it will not easily reveal non-uniform temperatures. The body diode of a power MOSFET can be used this way.International Rectifier included an IR micrographs in theirapplication note 1155.

author: coppercone2
author_rank: Super Contributor
timestamp: September 26, 2018, 12:21:35 pm
content: kinda relevant
optical transceiver and too high Rx signal - Page 1
Forum section: electronics / projects

author: m4rtin
author_rank: Regular Contributor
timestamp: January 17, 2013, 04:30:57 pm
content: Cisco switches display warning in case they consider optical signal received by transceiver to bee too high. For example(notice the "+" sign under "Optical Receive Power"):Code:Cisco3750switch>show int Gi1/0/2 transceiver detailITU Channel not available (Wavelength not available),Transceiver is internally calibrated.mA: milliamperes, dBm: decibels (milliwatts), NA or N/A: not applicable.++ : high alarm, + : high warning, - : low warning, -- : low alarm.A2D readouts (if they differ), are reported in parentheses.The threshold values are calibrated.High Alarm High Warn Low Warn Low AlarmTemperature Threshold Threshold Threshold ThresholdPort (Celsius) (Celsius) (Celsius) (Celsius) (Celsius)--------- ------------------ ---------- --------- --------- ---------Gi1/0/2 54.8 90.0 85.0 -40.0 -45.0High Alarm High Warn Low Warn Low AlarmVoltage Threshold Threshold Threshold ThresholdPort (Volts) (Volts) (Volts) (Volts) (Volts)--------- --------------- ---------- --------- --------- ---------Gi1/0/2 3.28 3.80 3.70 2.80 2.70Optical High Alarm High Warn Low Warn Low AlarmTransmit Power Threshold Threshold Threshold ThresholdPort (dBm) (dBm) (dBm) (dBm) (dBm)--------- ----------------- ---------- --------- --------- ---------Gi1/0/2 -2.5 1.0 0.0 -5.0 -6.0Optical High Alarm High Warn Low Warn Low AlarmReceive Power Threshold Threshold Threshold ThresholdPort (dBm) (dBm) (dBm) (dBm) (dBm)------- ----------------- ---------- --------- --------- ---------Gi1/0/2 -0.8 + 0.0 -1.0 -23.0 -24.0Cisco3750switch>Why is (very) strong optical signal bad? What is the physical phenomenon describing this?

author: jahonen
author_rank: Super Contributor
timestamp: January 17, 2013, 04:46:08 pm
content: I'm no expert but I think it is due to receiver analog circuitry (photodiode and preamplifier etc.) driven to saturation (or close to it), which can cause deterioration of BER (bit error ratio) due to various reasons, like increased jitter, skew or so.Regards,Janne

author: w2aew
author_rank: Super Contributor
timestamp: January 18, 2013, 02:39:41 am
content: Janne has it right. Too much optical power will overdrive the reciever which would likely distort the signal resulting in potential bit errors.