hybridfree/eevblog-posts huggingface dataset:
Fix up an old R/C Hummer H3 - Page 1
Forum section: electronics / projects

author: vgamesx2
author_rank: Regular Contributor
timestamp: August 24, 2017, 05:25:46 pm
content: So I have an old H3 like the one in the image below and I'm trying to get into it because servo for steering is having issues turning left and I also would like to modify it a bit, like adding a connector for lithium batteries.My problem is, as far as I can tell it's not as easy as removing all the screws to get inside and there appears to be little rivets or something holding it in the middle (I can't really tell), does anyone know how to open one of these without destroying the shell?

author: anishkgt
author_rank: Frequent Contributor
timestamp: August 24, 2017, 05:31:05 pm
content: How does it look like underneath ?Sent from my iPhone using Tapatalk

author: vgamesx2
author_rank: Regular Contributor
timestamp: August 24, 2017, 06:04:16 pm
content: Here's a full body shot and a close up of the two bits in the middle I mentioned.

author: anishkgt
author_rank: Frequent Contributor
timestamp: August 24, 2017, 06:12:25 pm
content: I can see star screws. Don't see any rivots.Sent from my iPhone using Tapatalk

author: vgamesx2
author_rank: Regular Contributor
timestamp: August 24, 2017, 06:18:32 pm
content: It's very difficult to see in person, the hole is very deep and if you shine a light in there it becomes shiny and too bright to actually make out what it is, so thus far this is the best look I've even had at it, also dunno about you but the second one looks more like a triangle screw to me.

author: vgamesx2
author_rank: Regular Contributor
timestamp: August 24, 2017, 06:36:13 pm
content: Alright, so I figured I'd try a few torx bits and they don't fit, on closer inspection it appears as if it might be a tiny hex screw (which I don't think I have) and the second one I really can't tell but it's certainly a different screw, looking at it it seems almost flat but at the slight angle I had my camera at it appears like a triangle screw.
Fixed point DSP book suggestion - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: January 31, 2020, 12:02:42 pm
content: Hi,Is there a book on the fixed point DSP, I have looked for good sources for ages. Any good tip, book, website, video tutorial on the subject would be highly appropriated.

author: Dmeads
author_rank: Regular Contributor
timestamp: February 02, 2020, 04:07:51 am
content: I just ordered the Uweye Meyer book yesterdayhttps://www.amazon.com/Digital-Processing-Programmable-Communication-Technology/dp/3642453082/ref=sr_1_2?keywords=digital+signal+processing+fpga&qid=1580615986&sr=8-2I heard it was really great for DSP, but also it has the added FPGA aspect.If you want to go the MATLAB route, check this one outhttps://www.amazon.com/Digital-Signal-Processing-Matlab-Examples/dp/9811025398/ref=sr_1_6?keywords=digital+signal+processing+MATLAB&qid=1580616136&sr=8-6Its from the same company as the first one which is highly recommended.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: February 02, 2020, 06:26:21 am
content: Thanks for sharing
Fixed point representation - Page 1
Forum section: electronics / projects

author: msr
author_rank: Regular Contributor
timestamp: July 05, 2015, 02:14:12 am
content: Hey guys,I would like to share with you a blog post I just wrote about "fixed point representation":http://theramblingness.com/2015/07/01/the-art-of-representing-floating-point-numbers-as-integers/This is the first post of three posts I'm planning to write about Digital Signal Processing.First we need to know how we can use floating-point numbers without using float or double variables but using ints instead (when a floating-point unit - FPU - is not available, of course).Then, on the next post I will write on how to implement some useful filters (moving average, exponential moving average, FIR and IIR), and on the last one I will share C code that implements all that stuff.It's not that I'm a big expert on this matter but I'm deeply interested by it and as such I would like to share my enthusiasm, in the hope it will be useful to somebody elseFeedback is greatly appreciated.
Fixed Voltage Regulator design for battery-powered device - Page 1
Forum section: electronics / projects

author: Alexandros81
author_rank: Regular Contributor
timestamp: December 15, 2018, 04:19:50 pm
content: Hi!I am designing a battery-powered device that consumes roughly at maximum load 300mA.The battery I am thinking of using is this battery pack ->https://www.ebay.co.uk/itm/12V-3000mAh-Super-Rechargeable-Li-ion-Battery-Pack-Wall-Charger-UK-AU-US-EU-Plug/352353688806?hash=item5209ea9ce6:m:mpG0OmWIHYoYrvrJpgkLAHw:rk:16:pf:0So I decided to go for this regulator ->https://export.farnell.com/microchip/mic5209-3-3ys/ic-reg-ldo-500ma-1-3-3v/dp/2510236According to the datasheet my design should be like figure 5. (page 12 of the datasheet) A 0.1uF capacitor between IN and Ground and a 22uF capacitor(tandalum electrolytic) between OUT pin and Ground. Am I correct?In page 10 of the datasheet it is mentioned that the input capacitor should be 1uF if a battery is used.In my case the battery pack is 12V so according to equation:(VIN(MAX)-VOUT(MAX)) x IOUT+ VIN(MAX)x IGNDI get a Power dissipation of [(12V-3.3V)x300mA] + (12Vx5mA) = 2.66WIs it necessary a heat sink?What if I use a 6V battery pack? then the power dissipation should be 0.87W. For this case no heat sink is required.Also if I want to use my device for an hour what the minimum mAh value of the battery pack should be if my device consumes 300mA?Thanks

author: Audioguru
author_rank: Super Contributor
timestamp: December 15, 2018, 10:20:58 pm
content: The battery and charger are extremely cheeeep, Chinese and purchased on ebay.Beware. Then maybe they will not work properly. (Big explosion then a hot fire!)
Fixing a board, and I'm trying to identify a couple of components - Page 1
Forum section: electronics / projects

author: guscrown
author_rank: Regular Contributor
timestamp: September 06, 2024, 01:37:41 am
content: Hey guys, I'm trying to repair a board, and I'm having trouble identifying a couple of compontns.The first one I believe is some kind of voltage regulator, and seeing the components around it I believe it's an LDO:The second one is being used as some kind of driver for a dual MOSFET (N-FET and P-FET in same package)I googled, copiloted, and looked at around 100 datasheets looking for those markings but I've failed.Anyone out there used something like this before?

author: Buriedcode
author_rank: Super Contributor
timestamp: September 06, 2024, 02:21:32 am
content: Top one could be:https://www.alldatasheet.com/datasheet-pdf/download/136409/TOREX/XC6219A502MR.htmlBottom.. dunno, tryhttps://www.s-manuals.com/smd

author: guscrown
author_rank: Regular Contributor
timestamp: September 06, 2024, 02:51:10 am
content: WOW!! That's a good find. It's the closest I've seen tbh.

author: DaJMasta
author_rank: Super Contributor
timestamp: September 06, 2024, 02:56:15 am
content: Is the mosfet pair direct logic drive? I see linear regs with G8, but also an XOR gate (TC7SET86)

author: guscrown
author_rank: Regular Contributor
timestamp: September 06, 2024, 03:07:37 am
content: The dual fets is an F7307 from Infineon. I think it may be that XOR gate.

author: Buriedcode
author_rank: Super Contributor
timestamp: September 06, 2024, 03:41:01 pm
content: Often when tracing out a board, the "context" helps alot - if its surrounded by large caps, probably a regulator. And inductor next to it, buck/boost/sepic etc.. As of course, does the pinout. Often just finding the GND pin(s) and Vin is enough to verify at least the function of the device.

author: guscrown
author_rank: Regular Contributor
timestamp: September 06, 2024, 04:30:47 pm
content: That's a good point. I know from some tracing done that the first component, the one with "LAMRRT" is a voltage regulator, probably an LDO, and since I don't see any feedback resistors around it, I assume it's a fixed output LDO with a Vout of most likely 3.3V for this system.If I assign pins like this:1 23 4 51 = looks like floating2 = also floating3 = GND4 = Vin5 = VoutThe other one is a bit hard to say, I am certain it is not a regulator, and I thought it may be some kind of logic, but since it's being used with a dual-fet (N and P) part, I'm now thinking that this is maybe a dual BJT.
Fixing apple wireless keyboard? - Page 1
Forum section: electronics / projects

author: TheBorg
author_rank: Frequent Contributor
timestamp: January 18, 2014, 04:20:14 am
content: I recently bought an apple wireless keyboard from eBay that said it was working, but when I got it a line of keys on the right side of the keyboard did not work. As the keyboard contacts are laid out in a gridded pattern, my guess is that one of the column lines got water in it or something. So I was wondering if anyone had any advice on how to try to get this working. Unfortunately, due to the amount of glue used in production and the welds throughout the keyboard, taking it apart is not a viable option, it would ruin the keyboard completely. So any advice on how to fix this circuit without actually getting into it? My hope is that it is corrosion based, and that I can soak the whole thing in isopropyl alcohol (diluted 50%?) for a few hours, and dry it out. I can remove the bluetooth board, so it would be unlikely for that to get soaked too bad. It's a long shot, but its worth a shot to try to get it working!

author: peter.mitchell
author_rank: Super Contributor
timestamp: January 18, 2014, 06:18:17 am
content: Why would you dilute it? Also, there is no reason to soak it, you should agitate it otherwise it won't do anything.

author: amyk
author_rank: Super Contributor
timestamp: January 18, 2014, 11:44:54 am
content: According tohttp://geekhack.org/index.php?topic=31981.0, isopropanol will soften the glue and allow it to come apart.But before going into the body of the unit I would open the plastic cover over the controller PCB and reseat the connector between the controller and membrane.

author: TheBorg
author_rank: Frequent Contributor
timestamp: January 19, 2014, 03:39:11 am
content: That's the first thing I tried, actuallySo my dad has a small ultrasonic cleaner, I have access to it, but only about half the keyboard would fit (enough to soak the keys that do not work). Would that be the best way to try to clean out anything in there?Isoproanol would allow it to come apart, but the membrane (I believe) is hidden behind a metal sheet with spot welds to the aluminum back. So that would probably not be an option unless I drilled out 40+ welds, which is an option but I'd rather not try it until I had to.Quote from: amyk on January 18, 2014, 11:44:54 amQuote from: peter.mitchell on January 18, 2014, 06:18:17 amI don't know- to keep the plastic safer? I'm guessing theres no need to, I don't know why I posted that. Would an ultrasonic cleaner be able to agitate it enough?
fixing broken vertical amp on Rigol DS1052/DS1100 - Page 1
Forum section: electronics / projects

author: wkb
author_rank: Super Contributor
timestamp: August 16, 2012, 08:08:32 pm
content: I seem to have managed to f* channel 1 on my Rigol DS1052 DSO. Most likely due to over-voltage.Has anyone ever attempted to repair a broken vertical amp on a Rigol DS1052?Channel 2 and the rest of the scope work just hunky-dory.Any suggestions, help & cuddlingin these frustrating times is much appreciated!

author: poorchava
author_rank: Super Contributor
timestamp: August 17, 2012, 08:19:37 am
content: I guess it's same as repairable as anything else, just given that you haven't fried pcb tracks. Also the question how much does the spare cost in signle quantity (maybe you can obtain samples?)

author: wkb
author_rank: Super Contributor
timestamp: August 17, 2012, 09:28:04 am
content: Yep, the idea is indeed to obtain some samples. A friend of mine has a company in RFID stuff who can get me those I think. I am studying 'A Hellene' -s schematics of the Rigol at the moment.At least I have equipment to do SMD work
fixing design for simultanios excitation of a sequencer - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: September 16, 2024, 04:12:28 am
content: Hello,The circuit is supposed to delay the output of P12 because the PNP is opening gradually.In previos version it worked great but i put P12 as a pulse and circuit just not working.The Veb is totally different.Veb is supposed to be 0 and rise gradually.But when i made P12 0-12V pulse my Veb is tottaly ruined.How can i fix it so Veb will rise gradually from 0 till PNP is opening?LTSPICE file is attached.Thanks.

author: john23
author_rank: Frequent Contributor
timestamp: September 16, 2024, 09:11:30 am
content: Hello,There was a basic flaw in my simulation because Vb started from 12V and went down.In here our Vb start to zero So Veb is 12V and going down Thus its always open.Is there a way to fix it?Thanks.
Fixing untented vias under BGA's - Page 1
Forum section: electronics / projects

author: elmohandis
author_rank: Contributor
timestamp: May 05, 2015, 08:02:45 pm
content: Hi Guys,I recently spun a board with 3 BGA's (1.0mm pitch 676-pin FPGA + 2x DDR3 SDRAM 0.8mm pitch).The board just came in and I noticed that I forgot to tent the vias under the BGA's (oops!).I am considering the following fix before sending it off for assembly:1. Order a stencil with cutouts in place of the vias to be tented.2. Apply curable solder mask to the vias only using the stencil.3. Cure with UV.Can someone share some advice? Is there a better way?Thanks!

author: elmohandis
author_rank: Contributor
timestamp: May 05, 2015, 09:33:38 pm
content: Considering somethig like this to use as solder mask:https://buerklin.com/default.asp?event=ShowArtikel%2811L470%29&context=subset:0;sel:SE;search:solder%20mask;se_name:vt;patchid:;tags:;pagecount:100&l=e&jump=ArtNr_11L470&ch=26481

author: marshallh
author_rank: Unknown
timestamp: May 06, 2015, 04:09:51 am
content: Try that method if you want, better is probably just to assemble it anyway. Just be more careful with the paste.

author: John_ITIC
author_rank: Frequent Contributor
timestamp: May 06, 2015, 04:17:09 am
content: I recently did some BGA site repair and came across this product:http://www.soldertools.net/bga-stencils-stencilquik/Essentially, the stencil has adhesive on the bottom such that it acts as solder mask as well as stencil for solder paste application. It is left in place when reflowing the BGA, which also prevents solder ball collapse and shorts.I also purchased a PCB rework kit, which contained high-temperature epoxy that can be used for touching up solder mask in case of damage. However, it was very hard to do properly since my pitch was 0.8 mm. The Stencilquik approach would likely be easier for you.http://www.circuitmedic.com/products/201-2100.shtml/John.
FL5150 Light Dimmer Circuit  - Page 1
Forum section: electronics / projects

author: Chet T16
author_rank: Frequent Contributor
timestamp: August 21, 2018, 07:34:09 pm
content: Hey all,I've built up a proof of concept dimmer that uses an ON Semi FL5150 dimmer controller and a Power Integrations LNK3204 demo board.The lnk3204 demo board has been modified to give 18v output and 300mA with an LNK3206. I've also switched the live and neutral inputs. Schematic attached as rdr506.pngThe FL5150 schematic from the datasheet is attached as fl5150circuit.jpg. Its actually the 120v 60Hz circuit but its the same for the 50Hz. The FL5150 derives its 17v VS power from the mains via resistor R1 in this circuit but in an effort to reduce power consumption I am feeding the output of the LNK3208 into the VS pin directly. My schematic is attached as fl5150_schematic.jpgThe problem i'm seeing is that one of the output IGBTs/FETs are not turning off. I originally had two IGBTs in there, when it didn't work i swapped them out with the same result. I then replaced them with two mosfets. The mosfets are 07N60C3's and the IGBTs are NGTB10N60R2DT4G's.A scope trace is attached as scope.jpgLooking at the schematics now after a few days away I'm wondering is there some offset to ground being created by the diode D2 in the LNK3206 circuit that is preventing one of the transistors turning off?

author: RPLaJeunesse
author_rank: Newbie
timestamp: December 16, 2018, 02:46:55 am
content: I suspect the LNK3206 stage is screwing something up, as the FL5150/60 chip GND pin needs to connect to the AC lines only through the MOSFET source pins & body diodes. As a quick test try using an isolation transformer to power the LNK3206 circuit. It might also help to draw up a full schematic so you can see what might be duplicate current paths. (FWIW I'm working on a trailing edge dimmer adapted from an old EDN design idea, and have been looking at the FL5160 as my next to try.)
Flame Detection Using Ionization Method. - Page 1
Forum section: electronics / projects

author: virgo_l
author_rank: Newbie
timestamp: June 17, 2012, 02:53:57 pm
content: I want to detect a flame in a gaz burner using the flame ionization method.There seems to be very less information about this on Internet on how to implemetn it practically.I got to know working principe for the method herehttp://articles.jimtrade.com/1/20.htmThere are various Flame Ionization Detector (FID ) sensors available but they cost a bomb and are used for Gas chromatography. For my application I don't want to do any kind of Gas Chromotography , I just want to know the presence/absence of flame. I tried other optical techniques ( using photodiode/light sensor ) but they are not that useful and the sensor is becoming hot. As the device has to be small and I can't put the sensor far away.So if anyone here has idea please advice.

author: SeanB
author_rank: Super Contributor
timestamp: June 17, 2012, 03:36:11 pm
content: Use a spark plug? Or use an ignitor probe for a furnace in the flame, and detect the current flow from the probe to the jet body.

author: abbtech
author_rank: Contributor
timestamp: June 20, 2012, 09:11:50 am
content: Hi Vergo,Many moons ago I used to install and service DetTronics flame detection systems. They are quite expensive but I am sure you could find a used one on eBay from time to time for a reasonable price.http://www.detronics.comAs an alternative I am thinking that with some effort you could build a simple version of the system which basically looks for the frequency of the flickering flame in the IR spectrum.http://www.desusystems.com/files/documents/FREQUENTLY%20ASKED%20QUESTIONS%20ABOUT%20FLAME%20DETECTION.pdf

author: amyk
author_rank: Super Contributor
timestamp: June 21, 2012, 08:29:50 am
content: Quote from: virgo_l on June 17, 2012, 02:53:57 pmThen why not use a thermocouple?

author: dda
author_rank: Contributor
timestamp: June 22, 2012, 05:17:20 am
content: Thermocouples would be easy but might be a little slow to respond. A CO2sensor could be put inline with exhaust gases.
flame speaker article (massless driver) - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: November 24, 2023, 05:03:22 am
content: We often hear about plasma tweeters, and less often about the flame speaker.But I found a good article about it. Its worth a read. Old (1970s) but well written and interesting.https://deramp.com/swtpc.com/PopularElectronics/May1968/Flame_Amplification.htmThey use a O/A flame with sodium (maybe dipping the tip in a bit of flux would work) to make a speaker. I believe it works at a much much lower voltage then your typical plasma speaker.

author: Whales
author_rank: Super Contributor
timestamp: November 24, 2023, 05:13:00 am
content: Also see "flame triode"http://www.sparkbangbuzz.com/flame-amp/flameamp.htm

author: coppercone2
author_rank: Super Contributor
timestamp: November 24, 2023, 06:26:57 am
content: that is two pieces of electronics made with fire. the third is thermionic generators to power that stuffneed a radio set that you can just throw in a fire placehallowed are the ori

author: CaptDon
author_rank: Super Contributor
timestamp: November 24, 2023, 03:06:55 pm
content: G.E. made a flame heated version of the 7077 ceramic vacuum tube. I suppose the cathode 'stub' rode in the rocket flame?

author: donlisms
author_rank: Frequent Contributor
timestamp: November 25, 2023, 02:24:07 pm
content: Hallowed are the Ori.
flame triode - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: March 27, 2023, 05:59:52 am
content: Hallowed are the Ori.I did not see a thread about this thing, and I find it fascinating, including the idea of using magnetic fields on the plasma to modify the parameters of the flamehttps://hackaday.com/2016/05/26/flame-triodes-dont-need-any-vacuum/Hallowed are the Ori.

author: gnuarm
author_rank: Super Contributor
timestamp: March 27, 2023, 05:23:27 pm
content: I never tried a flame triode, but I did build a flame speaker once. It used a propane torch and carbon electrodes. Back then I had a tube amp with a transformer output. It barely made sound when on the appropriate tap on the transformer. The other taps would not produce sound.I think we're going to need a bigger amp!

author: Gyro
author_rank: Super Contributor
timestamp: March 27, 2023, 07:10:19 pm
content: QuoteYou're going to need a horn at least. Trying to drive the air with an effectively 'massless' diaphram is going to be hard. Plasma tweeters work by thermally modulating (expanding) the air. With a propane torch and electrode, you're effectively just moving a constant temperature 'zero mass' flame around a bit.
Flash factory new STM32 with CAN bus - Page 1
Forum section: electronics / projects

author: mrburnzie
author_rank: Regular Contributor
timestamp: July 20, 2022, 03:07:02 pm
content: I have a project where I want to flash brand new STM32 using CAN BUS, thus achieving the effect that I solder the board, connect the device onto my can bus (which provides also power) and it automatically gets detected and flashed.I have found that some CAN Bus supported STM32 have a bootloader version that supports accessing memory through CAN Bus, which is exactly what I need.My question is that if I get the chips from factory, meaning they only contain the bootloader, what should I set the boot pins, so that after flashing via CAN Bus and restarting the device boots up to the program which I programmed into it. In case of updating the firmware again in the future I guess I would need to put it into the bootloader or can that be done in a different way?Thanks!

author: uer166
author_rank: Super Contributor
timestamp: July 20, 2022, 03:18:55 pm
content: Quote from: mrburnzie on July 20, 2022, 03:07:02 pmI believe you need to have the BOOT0 pin high, which will boot into system memory. When you're in bootloader, you have to follow the right sequence for it to auto-detect the CAN and enable FW update. I found few (e.g. STM32G4 parts that I use don't have it) STM32 variants that actually have a CAN bootloader even if they have CAN. After update, you need to set BOOT0 low (and keep it low), and power cycle or reset to boot into your application.

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 20, 2022, 03:46:34 pm
content: For some sort of factory programming I would not rely on the CAN bus boot loader and having the boot pins set to the right mode select.Using JTAG or SWD is far more universal. The board can have blind pads (or holes for a header) to allow pogo pins to connect to the JTAG or SWD signals as well as power. Program the FLASH and maybe even verify them and done.Connect the board to the normal power and it starts with your own firmware. In field re-programming can be catered for in your own firmware.

author: uer166
author_rank: Super Contributor
timestamp: July 20, 2022, 03:50:27 pm
content: Quote from: pcprogrammer on July 20, 2022, 03:46:34 pmYeah I'd agree, there are things that I don't think you can easily do using bootloader (such as changing option bytes to disable the BOOT0 function). I've used the UART system memory bootloader though by exposing the BOOT0/reset + UART pins over a digital isolator and it works good if you're doing something vanilla.
Flash programmer recommendation for 7x9 PLCC-32 - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: July 16, 2017, 01:12:10 pm
content: Hi Everyone,I'm going to be working with one of these soon:https://www.digikey.com/product-detail/en/microchip-technology/SST39SF040-55-4I-NHE/SST39SF040-55-4I-NHE-ND/2480210I saw a kit on eBay for $73 that is a flash programmer with a bunch of adapters, but sometimes there is a "goto" product I don't know about. What do you guys use for this?
Flash Quad SPI in single mode - Page 1
Forum section: electronics / projects

author: Felipe Lacerda
author_rank: Contributor
timestamp: June 05, 2022, 01:37:12 am
content: I need to write a quad flash SPI(s25fl116k) but the question is also generic.Can such a memory be written by a common programmer like CH341A(3.3v mod)?Or does it need to be written already in quad mode?regards.

author: moffy
author_rank: Super Contributor
timestamp: June 05, 2022, 02:25:43 am
content: Normally a quad SPI flash will boot up in single lane data mode, and data needs to be written to internal registers to change it to dual or quad mode, so my guess without looking at the datasheet, is that it should be writeable in single data mode. But again I haven't looked at the datasheet, so take my advice with a grain of salt.

author: ajb
author_rank: Super Contributor
timestamp: June 06, 2022, 05:36:52 pm
content: Many QSPI flash ICs will even start each transaction in single-SPI mode by default, and part of the transaction involves a command to switch to dual or quad mode for the remainder of the transfer. Without one of those commands, I think most QSPI flash ICs will handle the same set of commands as single-SPI flashes through a single data lane. You could compare the command sets of a conventional single-SPI flash that you know your programmer supports to the QSPI flash's command set to be sure. But if the programmer interrogates the flash IC before programming then it might still refuse to program a QSPI part if it doesn't recognize it.
Flashing AM32 on the FLYCOLOR Raptor 5 ESC - Page 1
Forum section: electronics / projects

author: TheBereavingBee
author_rank: Newbie
timestamp: August 22, 2025, 02:03:15 am
content: Hello,I need to configure the Raptor 5 ESC by FLYCOLOR to output telemetry data for my FPV Quad (don't ask why). Current firmware uses the defunct BLHeli32 and will present an error when trying to configure a telemetry output using BLHeliSuit32. I think its some issue with the servers hosting the firmware being shut down and it says something about a "pre release firmware"The only option that I have at the moment is to try and flash the ESC with AM32. Attached is the pinout of the programming pads for connection to an STLINK for the next guy who wants to do this...Currently working on the flashing it with AM32 but there is some write protection I'm still trying to get through.Wish me luck!
Flashlight build - Page 1
Forum section: electronics / projects

author: LesG
author_rank: Newbie
timestamp: April 02, 2023, 10:10:31 am
content: I am using the batteries and leds from a pair of old spotlights (from Walmart) tobuikd a pair of flashlights since the spotlights were damaged. They each use a pair of 18650 batteries and I purchased some charging circuits and need to know what resistors to use to run the leds. Any advice would be welcome. I know some basics but am still a beginner tinkerer. Thank you.

author: thm_w
author_rank: Super Contributor
timestamp: April 03, 2023, 10:45:16 pm
content: Beginners section is here:https://www.eevblog.com/forum/beginners/for future posts.https://www.circuitspecialists.com/blog/how-to-determine-resistor-value-for-led-lighting/Usual white LED might be 2.5 to 3.5V. So you'll size the resistor depending on how much current you want to draw when the battery is fully charged (4.2V). Then it will dim as the battery discharges.
flat cable pin order question - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: May 11, 2025, 12:20:50 pm
content: Hello , I need to deside wich color was connected to which pin so I wont confuse pins on my amplyfier. shown in the attached photos.there is a plastic bump on one side of the connector.How can I know the logic of this plastic 9 pin connector.How can I see the logic of it?How can I know which wire color connectin to what place in the plastic black connector?

author: bostonman
author_rank: Super Contributor
timestamp: May 11, 2025, 12:39:36 pm
content: I'm uncertain if a standard exists, but I'd measure them. Looks like the ends of the wire are visible, so stick a probe in the wire, a piece of wire in one of the socket holes, and measure.

author: pcprogrammer
author_rank: Super Contributor
timestamp: May 11, 2025, 12:51:10 pm
content: Usually there is also a pin 1 marker on the connector. This is an arrow symbol on the side of the connector where the bump is.When you look at the connector with the plastic bump facing you and the pin openings down, the arrow should be on the left. The outermost wire is connected to pin 1, then next one to pin 2, etc.Looking at your picture that would make the grey lead connected to pin 1, the white lead to pin 2, .. and the green lead to pin 8.

author: john23
author_rank: Frequent Contributor
timestamp: May 12, 2025, 08:30:58 am
content: Hello, I cant see any arrow as shown in the photo.I see that grey is 1 and green is 8.but I dont know the pin order in the black 4X2 box.Is there some document or schematics regarding the pin order of such boxes?Thanks.

author: Someone
author_rank: Super Contributor
timestamp: May 12, 2025, 08:40:14 am
content: Remember, this person has a multimeter:https://www.eevblog.com/forum/projects/did-i-get-faulty-amplifier-question/

author: pcprogrammer
author_rank: Super Contributor
timestamp: May 12, 2025, 09:05:07 am
content: The arrow is a bit vague, but it is there. See that attached image.Edit: Had to restart my computer to finish updates.For documentation on connectors like these, just look for information on manufacturers websites, like this one:https://www.jst.co.uk/productSeries.php?pid=168&cat=26The pin order is from front to back and left to right. So 1 is front left, 2 is back left, 7 is front right, 8 is back right. Front is where the bump sits, pin holes facing down.

author: jpanhalt
author_rank: Super Contributor
timestamp: May 12, 2025, 09:26:29 am
content: It's not been explicitly stated, but wire numbers are likely according to the cable (i.e., grey 1, white 2, black 3....) connections to a double row connector like that will have odd #'s in the top row (side with key) and even numbers in the bottom row.QuoteHowever, there are exceptions to that, so it's worth confirming with your meter.

author: eutectique
author_rank: Frequent Contributor
timestamp: May 12, 2025, 11:40:44 am
content: Quote from: john23 on May 11, 2025, 12:20:50 pmIt's hard to tell without seeing what is attached to the other end of this cheerfully coloured cable. Do you have a picture? Then the logic would be apparent.
Flat ribbon cable pitch - Page 1
Forum section: electronics / projects

author: EEVaditya
author_rank: Regular Contributor
timestamp: September 28, 2016, 05:50:47 am
content: Hello,What would be the appropriate Flat ribbon cable pitch for 10 pin (2x5) Female Socket/Connector having pitch 1.27mm.Want to make IDC Cable with 10 pin 2x5 1.27mm pitch Female socket/connector at both ends which can connect Male 10 pin 2x5 1.27mm Box header .

author: viperidae
author_rank: Frequent Contributor
timestamp: September 29, 2016, 06:44:41 am
content: If the connector pitch is 1.27mm and it has two rows the cable needs to be half that, 0.64mm

author: bicc1306
author_rank: Contributor
timestamp: September 29, 2016, 11:45:44 am
content: A standard pitch for cable is 1.27 mm, allowing for a two-row connector with a pin spacing of 0.1 inch (2.54 mm).

author: EEVaditya
author_rank: Regular Contributor
timestamp: October 05, 2016, 03:02:06 pm
content: what should be the core of flat ribbon cable for above specified specifications? how much the core matter?
Flat surface mount contacts - Page 1
Forum section: electronics / projects

author: luminantio
author_rank: Newbie
timestamp: August 15, 2016, 08:47:00 pm
content: Can anyone tell me where I can find surface mount contacts like the circular and oval shaped guys in this picture?I removed one to confirm that it's surface mount. I'm having a heck of a time finding them in any of the usual places.Thanks!

author: ovnr
author_rank: Frequent Contributor
timestamp: August 15, 2016, 09:29:51 pm
content: These things tend to be custom, because they're just stamped pieces of metal - the NRE costs are minimal. Not sure you'll be able to find them easily.Edit: For the center pin,thesemay be an option.
Flea market score - plasma TV power board - Page 1
Forum section: electronics / projects

author: poorchava
author_rank: Super Contributor
timestamp: January 01, 2014, 11:52:43 pm
content: I went to the flea market this sunday and scored a quite nice thing. I bought bag full of PCBs for what would be around 3€ and found this baby insideIt seems to be a Y sustain board from and LG plasma TV board. I have no use for it nor do I have a way to test it to sell it, so it goes for disassembly. It seems like a very nice source of power electronic parts. What I've found:3x IRFP4232 60A 250V 30 miliohm N-MOSFETS in TO-2473x STW9NK70Z 7.5A 700V 1.2 Ohm zener protected N-MOSFET in TO-2473x FQB6N70 6.2A 700V 1.5Ohm mosfet in D2PAK1x LM2585S-ADJ integrated flyback converterloads of 61FC4 ultra-fast recovery 400V/1.7A dual diodes in DPAKsome 178Mxx (78xx series regulators)2x huge Samwha 330uF/250V 105deg.C HE series capacitorssome VERY heavy gauge wire inductors and pulse capacitorsthere is also an about 10x15cm heatsink covering a module of some sort (not a hybrid I think) which I haven't desoldered yet and 3 other smaller pcb-mount heatsinks. There are also vertical daughter boards which seem to be power supplies of some sort.Anyway - there's about 30-40€ if not more in parts on that board(The STW mosfets alone are like $3 a piece in digikey)

author: Unknown
author_rank: Unknown
timestamp: January 02, 2014, 01:52:08 am
content: Quote from: poorchava on January 01, 2014, 11:52:43 pmIf you're impressed with that I've got loads ofold crapequipment and parts that is worth thousands going by prices on retails sites. You can have it all for £250.

author: JoeO
author_rank: Frequent Contributor
timestamp: January 02, 2014, 01:58:18 am
content: Quote from: poorchava on January 01, 2014, 11:52:43 pmNice find.If you use 1 or 2 of the parts, it has paid for itself. And you don't have to wait for the parts to arrive in the mail.
Flex cable repair - Page 1
Forum section: electronics / projects

author: Logan
author_rank: Frequent Contributor
timestamp: November 12, 2021, 04:21:07 pm
content: Hi guys.As picture shows, I need to replace this flex cable, but I cannot find it's model. Can anyone help me?Thank you!Edit: I gave up finding the exact same model, because it's likely a custom one, but could anyone help me finding the jump cable + breakout board as I asked below?https://www.eevblog.com/forum/projects/flex-cable-model-identify/msg3812267/#msg3812267

author: Terry Bites
author_rank: Super Contributor
timestamp: November 13, 2021, 05:16:20 pm
content: What's it part of?

author: wraper
author_rank: Unknown
timestamp: November 13, 2021, 05:24:34 pm
content: There is no model, it's a custom part for particular device.

author: Terry Bites
author_rank: Super Contributor
timestamp: November 13, 2021, 06:14:20 pm
content: Which particular device?

author: wraper
author_rank: Unknown
timestamp: November 13, 2021, 06:16:44 pm
content: Quote from: Terry Bites on November 13, 2021, 06:14:20 pmFrom which it was pulled out. How are we supposed to know?

author: CaptDon
author_rank: Super Contributor
timestamp: November 13, 2021, 10:15:39 pm
content: Sorry original poster, You're only going to get that from the original manufacturer. That was custom built and even if by some weird chance you find a part number it isn't an 'In-Stock' item for anyone but the O.E.M.!!! And I doubt they will sell you one anyway. Those look like user stress fractures from improper dis-assembly. Probably need a smaller crowbar.

author: Logan
author_rank: Frequent Contributor
timestamp: November 14, 2021, 04:19:12 pm
content: Thank you guys.The one need a smaller crowbar is myself. Seriously, the device is composed in such a way that it cannot be disassamled without damaging something, I damaged much more than this cable.So I just measured the pitch as 0.3mm, and I want a jump wire + breakout board with the same connector, then I can just solder the rest.The plug header's structure looks the same as this:https://www.newark.com/productimages/large/en_US/77AH5017-500.jpgI want a 13 pin one for the OP cable, and if possible, another 11 pin one.I found cables on sold with the same plug wire shape, but wrong conductor count and/or pin pitch, not even talk about a breakout board for this small pitch...

author: wraper
author_rank: Unknown
timestamp: November 14, 2021, 04:23:35 pm
content: IMHO scrape off the protective coating, and solder thin wire strands to connect broken copper traces.

author: Logan
author_rank: Frequent Contributor
timestamp: November 14, 2021, 04:25:24 pm
content: Quote from: wraper on November 14, 2021, 04:23:35 pmIt's completely tear apart now.Also, the tiny pitch is impratical for me to hand solder.
Flex PCB Design - Page 1
Forum section: electronics / projects

author: tarun172
author_rank: Regular Contributor
timestamp: June 12, 2013, 08:55:05 pm
content: Hi,I am new to Flex PCB Design . Does anybody have suggestions?I have not seen much from Dave on this topic.- Tarun

author: lindworm
author_rank: Contributor
timestamp: June 12, 2013, 11:59:28 pm
content: Hey,I didn't do any flex designs yet, but I planned to do some at one point and found two links in my bookmarks:www.4pcb.com/media/Mainstream%20Use%20but%20More%20Complex%20Designs.pdfhttp://www.allflexinc.com/PDF/GuideBookrev.pdfThere' s also an ehow on it:https://www.ehow.com/how-does_5628040_rigid-flex-assembly-process.htmlregards, lindworm

author: lgbeno
author_rank: Frequent Contributor
timestamp: June 13, 2013, 01:38:20 am
content: Itead has a flex option for $65. Looks interesting to me, I've always been fascinated by flex.

author: cwz
author_rank: Newbie
timestamp: June 13, 2013, 04:16:42 am
content: In general, some guidelines you will want to follow:Prefer rounded corners on traces over 45s/90sWhere pads go to traces, you will want the delineation to be gradual instead of sudden (e.g. don't take a 20 mil wide trace and have a 5 mil wide line exit directly from it). You do this to avoid stress fractures when the traces need to bend. An approach not unlike how you'd teardrop a via should generally be OK.If you need to solder the flex to a rigid PCB, you will want to provide plated through vias in the area where you're going to be soldering. Ideally you'd have matching pads on both sides of the flex, but if that doesn't work for whatever reason, the vias will give you a reasonable chance at soldering without a hotbar bonder.The price roughly doubles per additional layer, so if you can get it done in a single layer...If the flex does need to be, keep to about 3x flex thickness as your minimum bend radius. Also, prefer bends that are inward vs. outward. If you bend outwards with a sharp corner, you risk getting trace breakage that doesn't happen immediately. It will happen after your flex has been "in the field" for a few months. I've personally made that mistake.For small qty, you will probably get laser cut flex. Watch out for carbon marks/charring around the cut area. I'd leave a good margin of clearance from the cutout. Die trimmed flex will not have this problem, but it's not really economical in smaller qty. Steel rule dies can be made cheap, but the quality and consistency of the cut is not generally good.If you want to do assembly on the flex, consider either partially rigid flex, or stiffeners in the areas where components need to mount. If that's not an option, SMT assembly is still an option, it just generally requires the use of a vacuum table and special handling in the reflow oven.I think that's about all I can think for now.

author: tarun172
author_rank: Regular Contributor
timestamp: June 15, 2013, 06:07:42 pm
content: Thanks guys. This is good stuff. I will post more questions as we move along.- Tarun
flex pcb rework : how to expose a track ? - Page 1
Forum section: electronics / projects

author: jujun
author_rank: Regular Contributor
timestamp: November 21, 2019, 11:12:28 pm
content: Hello,Any clues on how to expose the copper of a track on a flex pcb (transparent orange ones) to be able to solder a wire on it ?I tried several things but nothing worksAny advices ?Thank you

author: jbb
author_rank: Super Contributor
timestamp: November 22, 2019, 12:03:43 am
content: Sometimes I carefully scrape off the cover layer with a scalpel. I do this under a magnifier or microscope.It’s not easy or pleasant, so I too would like some tips and tricks.It helps to tape the FPC down to a flat surface (such as a spare blank PCB).

author: KL27x
author_rank: Super Contributor
timestamp: November 22, 2019, 03:53:42 am
content: If you take a pointy Xacto blade and you grind the edge off until the point turns sideways, you will have a super narrow chisel.An FPC has a very thin center layer between pours. So you don't want to push the blade into the board, like you might do on a regular PCB. So it's hard to make a clean opening in the coverlay. You might expose more copper than you like when the coverlay tears. And be super careful when you get to the copper. If you scrape all the way thru the copper on accident, you are probably already exposing copper of the other side, because the center layer is so thin. And then you can create shorts.

author: all_repair
author_rank: Frequent Contributor
timestamp: November 22, 2019, 04:44:32 am
content: Fine sand paper, gently and carefully.
Flex seal on bottom of pcb - Page 1
Forum section: electronics / projects

author: mblyman89
author_rank: Contributor
timestamp: June 01, 2021, 02:30:48 am
content: Hello, I am curious if anyone has coated the bottom of their pcbs with liquid tape or flex seal to protect it and insulate it and if that is a practical solution to protecting the bottom of a pcb. If not, is there a suggested method for protecting the bottom of a pcb? I’ve seen some pcbs have a non conductive foam padding on them, but that stuff is really expensive. Thank you!

author: ataradov
author_rank: Super Contributor
timestamp: June 01, 2021, 02:59:18 am
content: There are specially designed polyurethane conformal coating compounds. I would not use any random hardware store stuff. A lot of it acidic and will eventually damage the PCB.

author: notsob
author_rank: Frequent Contributor
timestamp: June 01, 2021, 03:17:26 am
content: you could try something peters conformal coatinghttps://www.peters.de/en/products/elpeguard-conformal-coatings

author: Pete66
author_rank: Regular Contributor
timestamp: June 01, 2021, 07:39:47 am
content: It depends what you are protecting it against. I normally use lacquer. It works great and comes off with acetone when you need to take it off. I just use my wife's nail polish - its free.

author: fcb
author_rank: Super Contributor
timestamp: June 01, 2021, 08:33:43 am
content: Quote from: mblyman89 on June 01, 2021, 02:30:48 amWhat are you trying to achieve protection from? Issues with chemicals (which?) Physical media? Voltages present? Temperatures?We use silicone conformal coating for sealing against humidty. Mylar sheets for high-voltages held onto PCB with plastic rivets. Tufnol for high-voltage high-current stuff.

author: rsjsouza
author_rank: Super Contributor
timestamp: June 01, 2021, 12:09:18 pm
content: I have been using the conformal coating below (MG Chemicals 4223F) for about ten years on PCBs in the pool equipment (heavy chemical, dust and humidity environment) without a problemhttps://www.mgchemicals.com/products/conformal-coating/polyurethane-conformal-coatings/urethane-conformal-coating/I have seen silicone-based glues and caulks warp or otherwise damage PCBs during the curing process, so I would be very careful when using something not proper for the task.

author: mblyman89
author_rank: Contributor
timestamp: June 01, 2021, 05:06:28 pm
content: Thank you all for your input! I’m not sure what I’m protecting the circuit from really, it’s a 12v 1A firework controller, and it’ll always be protected from the elements and such, mostly. I just wasn’t sure how to protect the pcb so it would last a long time from just normal usage. I’ll look into the conformal coatings and epoxy solutions for now.
Flexi-rigid and flexi PCB's - Page 1
Forum section: electronics / projects

author: fcb
author_rank: Super Contributor
timestamp: November 26, 2014, 06:02:04 pm
content: Can anyone recommend a UK (or China/EU) manufacturer of flexi-rigids and flexi PCB's?

author: marshallh
author_rank: Unknown
timestamp: November 26, 2014, 10:08:52 pm
content: Myro

author: fcb
author_rank: Super Contributor
timestamp: November 27, 2014, 05:21:19 pm
content: Quote from: marshallh on November 26, 2014, 10:08:52 pmThanks Marshallh
Flexible charger project - Page 1
Forum section: electronics / projects

author: profdc9
author_rank: Frequent Contributor
timestamp: May 12, 2021, 10:41:28 pm
content: This is a battery charger based on a commonly-available ATMEGA328P for control and a common TL494 switching power supply IC. It is intended to be easily and cheaply reproduced, and is for experimentation with different methods of charging batteries. It is also useful as a power supply.It is licensed under the Creative Commons CC-BY-SA 4.0, attribution and share-alike clauses. The schematic, gerber files, and Arduino code is available under open source licenses.The device is intended to be powered from another unregulated or switching power supply, with up to 30 volts input.It is designed to be used independently of a computer, having a simple user interface of three buttons and a 2-by-16 LCD alphanumeric display. The software has been created in the Arduino environment to be easily modified and customized.WARNING: Since this device gives you the ability to specify the voltage and/or current you wish to charge with, it is easily possible to damage or blow up batteries with improper configuration. This is especially true of lithium batteries which can catch fire and be difficult to extinguish. The author is not responsible for damage or injury resulting from the use of the device, as it is intended for experimentation.The device must be calibrated before used, with the calibration parameters stored in EEPROM. To do this, you need a voltmeter, a calibrated resistor with a known resistance from 5 to 10 ohms, and a wire to use as a short circuit load.The project's github is athttps://github.com/profdc9/FlexibleCharger
Flexible display / screen eval. kits - Page 1
Forum section: electronics / projects

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: May 15, 2018, 04:54:37 pm
content: Dear all,do you know of anyone producing some kind of evaluation kit for their flexible displays? A couple of demo units are shown by Samsung, LG, etc. on the various consumer and industrial client fairs every year, but apparently there is nothing even remotely ready for market.However, there must be some kind of demo gear around.I am looking for full color OLED / AMOLED screens, could only findvarious flexible e-ink displays.Any good sources for further inquiries or even buying flex screens?Thank you and kind regards,Frederik