hybridfree/eevblog-posts huggingface dataset:
Reprogramming an ST72F324J4T6 in circuit? - Page 1
Forum section: electronics / projects

author: ledtester
author_rank: Super Contributor
timestamp: August 15, 2019, 05:31:23 pm
content: I've got a late 90s/early 2000s consumer device which uses an ST72F324J4T6 mcu, and I'm wondering what options there are to reprogram it in-circuit.My research indicates the ST7-series is obsolete by now, and the programmers for it (like the ST7-STICK) are either unavailable for very expensive.I did find this open source project:http://www.spen-soft.co.uk/but the firmware is written "in ST7 assembly" for an ST72F264 - talk about a chicken and egg problem!Some questions:- from the pic of the PCB, does it look like the ST72F can be reprogrammed in-circuit? After all, there is "ICCDATA" and "ICCCLK" silkscreened on the board. OTOH, I don't even know if the mcu is locked or not.- I'm thinking of translating the spen-soft project firmware to a more modern mcu platform. Any recommendations for an mcu choice which might make the job easier - i.e. something which is architecturally similar? Maybe an STM8 Discovery board?- Any other ideas for talking to the ST72F in-circuit?
reprogramming the Genius G540 chip programmer - Page 1
Forum section: electronics / projects

author: jared6502
author_rank: Newbie
timestamp: September 07, 2012, 11:31:59 pm
content: I have one of these programmers, and can tell you that while the software is definitely lacking features, including ones mentioned as part of the sales pitch, I think it has a lot of potential to be one of the most useful programmers available for under $60 if the exact way it works can be determined, and if new software were written to take advantage of it.From a quick look at the board, the entire programmer is controlled by a c8051f340 microcontroller, which is connected to the USB port. It controls a CPLD and several shift registers, open collector buffers, and discrete transistors to manipulate the pins of the socket. On a hunch, I decided to disassemble one of the *.stg files, specifically TestExe.stg, included with the programming software (which can be downloaded from the company's website :http://www.stg51.com/.It's in Chinese, so it might be hard to navigate) using a disassembler for the 8051, and it appears to contain some code used to test the functionality of the microcontroller. I'm not sure, but I'm assuming that all of the *.stg files are actually code for the microcontroller, and are uploaded to it through the USB interface when the selected device changes. As far as the software on the computer goes, all that is necessary to work with the programmer is to interface to the Silicon Labs USB driver included with the manufacturer's programming software.If anyone has any more information they can provide on this programmer, or is willing to experiment on one they own, it would be very helpful. I don't have the programming adapter needed to connect to the microcontroller and reprogram it, and it's very likely that the flash is locked, preventing it from being read.

author: amyk
author_rank: Super Contributor
timestamp: September 08, 2012, 10:47:44 am
content: 8051s are Harvard architecture (separate code/data) and looking at the datasheet, this particular model doesn't have any special boot-from-USB functionality (unlike e.g. Cypress's PSoC series). However it does support ISP, so the software may contain a bootloader that reads code from USB and writes it to the flash, although this is a terrible way of doing it from flash endurance standpoint. If it does do that, then the flash must be unsecured, as otherwise the device would be unable to program itself afterwards through USB.If I were you, the first thing I'd do is determine the schematic, so you can see which pins are controlled and how. Then attempt to read what's in the MCU; the datasheet says it's a 2-wire serial interface, so it may be possible to just bit-bang it.
Repulsion Motor Commutator Grounding/Isolation - Page 1
Forum section: electronics / projects

author: ransonjd
author_rank: Contributor
timestamp: March 11, 2020, 01:44:46 pm
content: I'm in the process of restoring a 1923 Hobart 212 meat grinder. It's powered by a 110V, 60Hz, single phase, 1/4 HP AC repulsion motor which is built directly into the case of the grinder. The motor has two brushes in the back which are shorted via a copper alloy frame. The shorting frame has a direct, metal-to-metal connection to the case of the grinder. I had the motor megged, and it's in good shape despite 100 year old insulation.I would like to ground the casing of the grinder. I'm mildly concerned about the commutator's connection to the casing. Since the armature has no direct connection to AC mains, and the brushes just short the windings via the casing, nominally, no current should flow off the casing if I ground it. However, because this is an induction machine, I worry that may be woefully optimistic. So I'm considering two options.1. Just ground the casing, throw it on a GFCI outlet, and see what happens.2. Ground the case. Put a piece of Nomex or fish paper behind the grounding frame and replace the metal fasteners holding it in place with PEEK.The first option is the easiest, but I feel like the 2nd option is correct. A 1946 Hobart A-200 mixer that I restored was built this way originally, with fish paper and insulating sleeves for the fasteners.Does anyone have any input?

author: Zero999
author_rank: Super Contributor
timestamp: March 11, 2020, 04:04:47 pm
content: I don't see a problem. The current loop between the brushes is only connected to ground at one point and it's well isolated from the mains by the air gap and winding insulation so no current will flow to earth.Go with option 1. If the GFCI trips, it'll probably be leakage from the stator, rather than the commutator.
Repurpose 36V 18A Charger - Page 1
Forum section: electronics / projects

author: metrologist
author_rank: Super Contributor
timestamp: April 28, 2022, 06:02:27 pm
content: For golf carts, as scrap, but may work as designed. The output has 3 pins. Thinking of making it a linear benchtop supply, either just multiple output or variable with LCD display. I expect to just salvage the transformer, rectifier, and caps if still good and use the same box.same as this, different brand.https://www.amazon.com/Accusense-Intelligent-Charger-Crowfoot-Connector/dp/B009F0IANKAnd any other thoughts of what this could become?

author: BrokenYugo
author_rank: Super Contributor
timestamp: April 28, 2022, 07:44:10 pm
content: I think a linear bench supply that big usually utilizes a secondary with one or more taps, along with an automatic tap changer circuit, so the pass transistor(s) don't have the full voltage across them at all times. That doesn't make using it for a linear bench supply impossible, you could even go so far as unwinding the secondary to add some taps, but the transformer is less than ideal as-is.It'd probably make an ok start for the PSU for a huge class A audio amp.

author: metrologist
author_rank: Super Contributor
timestamp: April 30, 2022, 12:30:21 pm
content: I know I injected the "linear" term into the discussion but realize the simplest thing to do is just pop in a Rui Deng DC-DC converter module, and I have one with blown fets. Would not even need to change the original function.Or there might be enough copper to make copper jaws for my bench vise.
Repurpose HPE HSTNS-PL41-1 PSU - Page 1
Forum section: electronics / projects

author: johnysmrz
author_rank: Newbie
timestamp: July 11, 2022, 06:29:44 pm
content: Hello,i recently got (for free) bunch of HP HSTNS-PL41-1 server PSU and i would like to repurpose them for a high current lab power source since they can deliver 66A.The main problem is i am unable to find any pinout description so i tried logical thing which was to connect shortest pins (PSU should start after other pins are connected) and PSU seems to turn on and voltage apperas on two big pins but it is only 6.6V which is not correct. I even tried to put some load on output (1k resistor) but still 6.6V.Is there any other thing that i should try before full disassamble?

author: eblc1388
author_rank: Frequent Contributor
timestamp: July 12, 2022, 02:27:32 pm
content: Quote from: johnysmrz on July 11, 2022, 06:29:44 pmThere is a general method to determine which pin to enable the PS to startup in the following thread. Worth a try, good luck.https://www.eevblog.com/forum/projects/power-supply-extreme-networks-ps2336-ye-how-to-use-it/msg3729547/#msg3729547

author: coromonadalix
author_rank: Super Contributor
timestamp: July 12, 2022, 02:33:11 pm
content: check rc group forums, they uses server psus as battery chargersEDIt try this ?? with ggogle translatehttps://www.rc-network.de/threads/hp-hstns-pl41-800-watt-netzteil-f%C3%BCr-isdt.781098/

author: johnysmrz
author_rank: Newbie
timestamp: July 12, 2022, 11:27:02 pm
content: You are my savior! I can confirm that connecting all 3 left most pins will start PSU fully and i am getting 12V on main pins

author: nexus
author_rank: Regular Contributor
timestamp: July 13, 2022, 01:59:46 am
content: A lot of crypto miners use this style of HP server psu. There are tons of breakout boards for pcie power:https://www.ebay.com/itm/403634041698You might be able to use these or reverse engineer and get the right connectors to design your own boards.

author: Crunch69
author_rank: Newbie
timestamp: March 13, 2024, 09:13:12 pm
content: Need info how to increase voltage on these supplys

author: coromonadalix
author_rank: Super Contributor
timestamp: March 14, 2024, 01:44:31 pm
content: ask on RCgroup ... better chances there

author: Crunch69
author_rank: Newbie
timestamp: March 14, 2024, 07:39:17 pm
content: Tried
Repurposing an LCD monitor from an old 2005 DVD player - Page 1
Forum section: electronics / projects

author: Davey Chan
author_rank: Newbie
timestamp: June 22, 2020, 12:18:03 am
content: I was cleaning out my stuff from my closet and I found my old portable dvd player (INSIGNIA IS-PD040922). I decided to tear it down to see what use I can get out of it since I have no use for it.The screen is what interested me the most, and I was wondering if there was anyway to get the LCD working with a controller board. There doesn't seem to be a controller board for it when I googled, and was wondering if any of the universal controller boards might work.The screen is an LG LB070W02 LCD screen (https://www.spectrah.com/product/lcd_panel/lg_lcd_panel/LB070W02-s.pdf).

author: james_s
author_rank: Super Contributor
timestamp: June 22, 2020, 01:11:51 am
content: Most of these will have a fairly simple interface with 6-8 bit digital RGB, H and V sync and a dot clock. It's a whole lot easier to figure out the pinout if you still have the original device it was used in and can power it up and scope the pins.

author: amyk
author_rank: Super Contributor
timestamp: June 22, 2020, 02:33:23 am
content: That's an analog LCD. You'll need to look for 480x234 analog LCD controllers, they are often used for video as the resolution is too low for most "computery" things. It should also not be too difficult to drive with an FPGA.

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 22, 2020, 02:35:33 am
content: See if there's an analog video *input* on the player. That would make it trivial to repurpose if you can get it to work. Even if there isn't, sometimes the display controller has a composite or Svideo input that you can make use of - looking up datasheets helps a lot. (Over 10 years ago, I combined a DTV converter box with a broken portable DVD player to make a portable digital TV.)

author: TheMG
author_rank: Frequent Contributor
timestamp: June 22, 2020, 02:56:29 am
content: It's probably composite analog video into the LCD driver board. Pretty common for many portable DVD players in those days, since DVD decoder chipsets that output analog video as well as LCD drivers accepting an analog video input were very common, so manufacturers just put the two together.Very likely the shielded cable is the composite video in, and the rest are power and control signals (on/off signal, backlight brightness, things like that).
Repurposing an old IR remote - Page 1
Forum section: electronics / projects

author: DrG
author_rank: Super Contributor
timestamp: November 14, 2020, 10:26:44 pm
content: BLUF: Just a little hobby project for S&G.I was going through this thread -https://www.eevblog.com/forum/chat/making-a-simple-ir-transmitter/msg3299420/#msg3299420- where I said"I didn't have a need for a great distance, but if I did, I would go toward cannibalizing one of the many old remotes still hanging around long after their devices have gone away.". That got me thinking about doing just that and this is what I came up with.Here is the remote. I think it was from an old VCR (Yes, kids, many of us had VCRs).This is why you take the batteries out of things before you toss them in a box.Looking into it a bit, there is not much apart from the keyboard. No doubt, this is the brain.I looked around a bit for info on the chip, but not too hard because although I am sure it runs the keyboard and the IR transmitter, I am not really interested in figuring out how to use that chip. I just want a general purpose IR transmitter.Here you see the small number of additional components. A 455 kHz ceramic resonator, with its two caps, a 2.2 ohm current-limiting resistor, a C2120Y NPN transistor (datasheet available), and a power supply cap.That's it, except for the two IR LEDS on the front end with a lens....that's the part I wanted for sure...and since the transistor and current-limiting resistor are there for the taking, maybe I can combine everything on a small board.On the left is what I think is the schematic (minus the BU3738F stuff) and on the right is the schematic for the circuit I want. Note that I have it set up so that I can easily add to the current-limiting resistor. I measured the draw of the original circuit at neat ~240 mA at 3.0V and I might not want it that "strong", especially if I want to use it at 3.3V or 5V and with a PS that might not be able to supply that much current. But, I could use it as is if I wanted maximum distance capability.Out comes the Dremel with the saw attachment (I love that thing) and after a little coercion, de-soldering, re-soldering and a bit of cursing, I get this.Slap the top on and it is breadboard friendly.Did some testing and everything works as it should, Clean up, make a file with some notes, and it goes in the parts drawer.That's all I got
Repurposing Commercial Connectors - Page 1
Forum section: electronics / projects

author: hughes_k
author_rank: Contributor
timestamp: April 07, 2017, 05:30:51 pm
content: Hello,I'm working on designing a large test fixture, and am having some trouble finding a connector that has high cycle counts on both the device and the fixture side. The device side connector will not be used in the final product, but will be hosted on a test interface board.So the idea would be to connect the DUT to the interface board, and then the interface board to the test fixture. I can't connect the DUT directly to the test fixture.Interface board cost requirement is quite low ($1 - 5 maximum), but cycle count on the interface board has to be greater than 100.I think gold fingers on the interface board would be ideal, but the fixture side connector tends to have both very high pin count (I need less than 10) AND low cycle count (just as a typical example, PCI seems to be less than 100, where I need >= 1k).Ultimately, my question is:USB 3.0 connectors are relatively cheap (<$1 on both sides in quantities ~1k), have high cycle count, and have enough pins for my needs.Aside from the issues of a user plugging an interface board into a PC or a flash drive into the test fixture, are there other reasons this approach (using commodity connectors in non-standard applications) should be avoided? Does anyone have any experience doing this industrially?And a second question would be:Does anyone know of low pin-count, high cycle count card edge connectors?Thank you!

author: Ian.M
author_rank: Super Contributor
timestamp: April 07, 2017, 06:00:12 pm
content: Its presumably a high value test fixture, but the adapter boards must be dirt cheap, so I would suggest that replaceable pogo pins on the main board, and a custom made ZIF card slot, machined out of a suitable rugged insulator (or possibly ESD dissipative plastic, with the pogo pins in insulating sleeves and clearance recesses for each card finger so the plastic doesn't provide a resistive leakage path) that only allows card insertion/removal with the operating toggle lever open (by a pair of locking holes in the board edge), and moves bodily sideways on bushes running on another pair of pins outside the slot ends to slide the locking holes over fixed pins, and bring the card into good contact with the pogo pins.For a cheap & NASTY solution, you might be able to repurpose a full size SD card socket - with gold plated contacts a cycle life well over 5K should be possible. Block SD card insertion by adding a pin or thin blade just in front of the slot with a corresponding slot in the card PCB. If you need more than 9 contacts or loose one to the pin, you could mount two SD sockets inline. Put it on a carrier board with an edge connector, and matching socket on the main PCB and make a couple of spares for when it does wear out.
Repurposing HDD head preamplifier - Page 1
Forum section: electronics / projects

author: shakalnokturn
author_rank: Super Contributor
timestamp: March 17, 2023, 02:23:13 am
content: Just a thought, curious to know if anyone else has had the same one..I know they're very application specific, that datasheets for anything recent are unavailable, that they have a decent bandwidth but anything above 500MHz is going to be mounted to the head assembly itself as a mystical COF.All these dead hard disks, plenty of projects where they're turned into clocks, or "musical" devices, what could be done with the preampifiers?

author: Psi
author_rank: Super Contributor
timestamp: March 17, 2023, 02:26:57 am
content: I've seen people repurpose the amp and head motor to make laser show galvo mirrors.

author: MathWizard
author_rank: Super Contributor
timestamp: March 17, 2023, 04:47:44 pm
content: Whats a mystical "COF" ? I have some junk hardrives. I've only probed there spindle motor, and not much else.Can the sensor in the head do anything else useful besides read super small changes in a mag field, right under it ?? Assuming they even work by sense the mag field directly these days

author: shakalnokturn
author_rank: Super Contributor
timestamp: March 17, 2023, 05:31:13 pm
content: Attached a photo borrowed from a Canadian website.Recent HDD's have the preamp mounted on the head stack, as close to the heads as practically possible, on a flexible PCB (COF: Chip On Foil) with no reference to be read making them mysterious if not mystical.Quote from: Psi on March 17, 2023, 02:26:57 amDoes that involve using the existing tracking servo as designed, mounting a mirror on the arm and then seeking particular tracks over the original interface to move the arm?

author: Terry Bites
author_rank: Super Contributor
timestamp: March 17, 2023, 08:11:26 pm
content: Sigh.....

author: MathWizard
author_rank: Super Contributor
timestamp: March 17, 2023, 10:55:22 pm
content: If it wasn't for the plastic layer, I'd be curious to see how hard soldering on something like that would be.

author: BrianHG
author_rank: Super Contributor
timestamp: March 17, 2023, 11:54:55 pm
content: Here is a dirt cheap 1$ 4 channel 3GHz differential comparator amp.It can take in differential signals down to around ~0.1v and output differential LVDS digital and even drive a lengthy cable.NXP IC, PTN3366BSMP

author: BrianHG
author_rank: Super Contributor
timestamp: March 17, 2023, 11:57:26 pm
content: Quote from: Terry Bites on March 17, 2023, 08:11:26 pmI know, he is describing 2 different things.

author: Psi
author_rank: Super Contributor
timestamp: March 18, 2023, 02:18:04 am
content: I was talking about the mechanical head with its coils and the IC the drives the coils.Agree, preamp was the wrong word.
Repurposing old car electronics is always fun :) - Page 1
Forum section: electronics / projects

author: Muny
author_rank: Contributor
timestamp: August 22, 2015, 03:09:39 am
content: This was intended for the bin (faulty power switch, nothing a toothpick couldn't fix), but I decided I must have it as soon as I saw it.

author: WZOLL
author_rank: Regular Contributor
timestamp: August 22, 2015, 05:24:52 am
content: Nice. At least I know I'm not the only person to know that song.

author: Muny
author_rank: Contributor
timestamp: August 22, 2015, 06:25:33 am
content: Quote from: WZOLL on August 22, 2015, 05:24:52 amProleter is pretty great

author: fivefish
author_rank: Frequent Contributor
timestamp: August 22, 2015, 07:27:07 am
content: Back in the 80s, me a broke college student, I used a car stereo and EQ/booster along with some DIY speaker enclosures for my bedroom sound system. It's pretty sweet sounding.

author: SeanB
author_rank: Super Contributor
timestamp: August 22, 2015, 08:37:44 am
content: I did the very same for my first PC, as i did not like the speakers on offer as "PC speaker" ( otherwise known as 2 expensive strangled chipmunks), so got a slightly used car EQ amplifier on auction ( was $2 IIRC), used the 12V PC PSU rail to drive it , and added some small 4R speakers also bought on auction. Was loud enough, and worked well for around a decade, only going as I upgraded from a 486SLC to the first Pentium, and moving to a PCI sound card instead of the old original Sound Blaster ISA card. Then I used a set of speakers and a Kenwood component amplifier instead.Only mod to the car amplifier was to add an extra 2200uF of capacitance to the input, a series inductor to reduce the noise on the supply rail, and removing the 2 input 47R resistors on the amplifier so it would work better with the sound card line out, as the input was in any case terminated in 10K after the input capacitor.

author: Muny
author_rank: Contributor
timestamp: August 22, 2015, 04:50:50 pm
content: Quote from: fivefish on August 22, 2015, 07:27:07 amI really dig the look of that, do you have a model number or anything for it? If only modern car stereos possessed the same beauty as older ones...

author: fivefish
author_rank: Frequent Contributor
timestamp: August 22, 2015, 08:00:56 pm
content: QuoteIt's a Pioneer KP-500.They're very good sounding... now going on eBay for $380-$450! Hard to find nowadays.Wish I kept mine back then.... but who knew.
Repurposing Samsung WiMax base station to SDR - Page 1
Forum section: electronics / projects

author: aporte
author_rank: Newbie
timestamp: March 19, 2021, 09:32:54 pm
content: Hi All,I have purchased several cheap Samsung WiMAX U-RAS Premium-F radio units (a part of base station) with probably dead power amplifier. The radio unit has 3 PCBs inside:1) Power supply or DC-DC converter2) Power amplifier3) Baseband/DSPThe baseband board has some old PowerPC CPU module that can been seen (googled) in some cheap china CNCs also. If somebody can provide PowerPC module documentation (pins mapping, schematics) then I can reverse engineer baseband/DSP board and repurpose it into SDR. If somebody can provide baseband board schematic then a lot of time can be used for SDR software development. In case of baseband board reverse engineering I can unsolder FPGA and reverse engineer traces and connections using multimeter and x-ray imaging. The PowerPC CPU module photos can be seen in the attachments.High resolution photos can be downloaded here (7z package):https://drive.google.com/file/d/17YVRUEM170xsWr_3UPIBC27ppiUgonJx/view?usp=sharingThe same module can found in CNC board at the following russian forumhttps://electronix.ru/forum/index.php?app=forums&module=forums&controller=topic&id=152630#commentsPlease help find documentation, BSP or SDK for this PowerPC module. The board has the following IDs:- CS111303D- PPChameleon- DAVE Electronics System HouseLinkshttps://www.yumpu.com/en/document/view/39272693/ppchameleon-ar-ultimate-solutionsThanks in advance!

author: nater21
author_rank: Newbie
timestamp: October 06, 2021, 09:31:41 pm
content: Hi man, Just saw your post, I did a lot of research as I have 2,400 of these in my inventory new. This is a link to all resources that I managed to accumulate on the device including all schematics and pinouts. Hope this helps if you are still looking. Please le me know if you may know a customer for my parts in stock. Regards, NathanEdit to include a link to those for sale:https://www.continuumtech.ca/detail.php?control=1034047nathan.fry@continuumtech.cahttp://continuumtech.ca/PPChameleon.zip

author: aporte
author_rank: Newbie
timestamp: October 10, 2021, 01:11:49 am
content: Hi Dude, thanks for reply and sharing the archive ... I have contacted the board manufacturer also and they were pleased to share the full BSP CD-ROM package (with documentation) for free because board is too obsolete (see the following link)https://drive.google.com/file/d/1AkFHhtEl5CsOawDf6Cuizx3gp0KNdB4_/view?usp=sharingThe manufacturer ishttps://www.dave.eu/en

author: nater21
author_rank: Newbie
timestamp: October 11, 2021, 10:18:39 pm
content: Yes, is quite obsolete, obviously not looking for the original value. Was hoping it might be of use either for service requirements and/or hobbyists... let me know what you manage to do with it, my brother was going to try a project with it also.Good luck! Nathan
Repurposing the Apple Siri Remote 3rd Gen - Page 1
Forum section: electronics / projects

author: Ogrek
author_rank: Newbie
timestamp: June 20, 2024, 03:37:40 pm
content: Hi all! I am trying to get an Apple Siri Remote 3rd Gen (USB-C) to work with my PC and was wondering if anyone had looked into decrypting the communication protocol it uses. From what I know, it uses Bluetooth but has a non-standard interface that makes it invalid and can't be recognised as a HID (I get a driver error on Windows). I saw a teardown that it uses a nRF52840 microcontroller capable of RF including Bluetooth among other protocols. I have bought a nRF52840 dongle and tried to usehttps://www.nordicsemi.com/Products/Development-tools/nrf-sniffer-for-bluetooth-leto sniff but I could not find the device on Wireshark. It even refuses to pair with my PC anymore after I connected it to an Apple TV (I don't think they have an unpair feature, even if the button was pressed in the rare occasion it shows up on the Apple TV menu).Is anyone able to help me with this? I like the build quality and want to use it for purposes other than the Apple TV but I also don't want to tear it apart since it seems you'll have to damage the device by doing so. My PC seems to recognise something when it's connected via USB but I don't know if that's seeing the microcontroller or not.
Reputable compact isolated 12v wall warts? - Page 1
Forum section: electronics / projects

author: anfang
author_rank: Regular Contributor
timestamp: November 15, 2016, 07:36:49 pm
content: I would like to buy some 12v wall warts. They should be compact (similar to the current USB chargers) and properly isolated. On Aliexpress and eBay there are plenty of them, but I fear about their safety.Do you know any reputable source for 12v wall warts?

author: amitchell
author_rank: Regular Contributor
timestamp: November 16, 2016, 12:55:40 am
content: I have CUI, Volgen, Phihong and MeanWell. The MeanWell SGA series is the nicest of the lot. Mainly noticing that the cable is thicker on the MeanWell. I tested the output ripple on the four brands a while ago and they were all close, don't have the numbers handy though.

author: grifftech
author_rank: Frequent Contributor
timestamp: November 17, 2016, 04:30:06 pm
content: how much power output do you need

author: jolshefsky
author_rank: Regular Contributor
timestamp: November 29, 2016, 07:30:38 pm
content: I finally got around to cracking open the 12V wall wart I last bought. I was pleased to find details like a fuse and 7mm creepage although no clearance slots and capacitors branded "Gather" all around. It's a Triad Magnetics WSU120-0700 series; 120VAC in, 12VDC @ 700mA out.Not sure about the OP, but I would like to find one that's very very much better (e.g. Nichicon caps and decent clearance.) These go out with pretty expensive tools so I'm paying attention to quality, and this one isn't terrible but I'm looking for something better than "barely average."
req. datasheet/ or working of IC 3710b (for buzzer) - Page 1
Forum section: electronics / projects

author: vjkumar
author_rank: Newbie
timestamp: July 29, 2019, 06:50:46 am
content: Hi,I am trying to find 3710b (6Pin-IC), but could not find on google.I am using this in small buzzer which is working at 3V dc battary.Also I am unable to get the datasheet of this IC. Please somebody help me in this.
Request datasheet for pcf7947at chip - Page 1
Forum section: electronics / projects

author: wawinfo
author_rank: Contributor
timestamp: December 16, 2023, 11:25:29 am
content: Hi. I have a Renault key kard that uses pcf7947at chip as complete solution for immobilizer and RFID, now I have problem for just unlocking the door, the rest buttons and functions work perfectly.I have tested all traces and components because I do repairs for many years. Can anyone provide me complete datasheet for that chip?Description goes long sorry.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 16, 2023, 02:03:07 pm
content: now classified as obsolete on many part providers, since it deals with some car security, finding the datasheet may prove difficult, tried on many sites no availmany dumb links, many redirections for the pdf ...
Request for feedback on LED PWM driver output circuitry (Part 2) - Page 1
Forum section: electronics / projects

author: daviegravee
author_rank: Newbie
timestamp: October 18, 2024, 08:36:24 am
content: I am looking for feedback, thoughts and general input on a design I am working on. This is a follow up to my previous post:https://www.eevblog.com/forum/projects/request-for-feedback-on-led-pwm-driver-output-circuitry/Key changes since the last post:Cabling inductance and capacitance has been modelled as per one user's suggestionFlyback diodes have been added to prevent ringing at the output (D1 and D2 in the simulation file)Output filtering capacitor has been addedFerrite beads have been addedGate driver IC has been added. The design will actually use the UC27444, however there is no SPICE model available for this part afaik.MOV has been added to the output, part not spec'd yet but will probably be the Bourns ZV60K1206121NIR1I have attached a screenshot of my LTSPICE file that simulates one single output stage. There will be 24 of these in total.The key points of the current design are:PWM, constant voltage driver;Each channel must be able to handle a maximum 4A, at 48V (24V will be more common in practice);The design is not rated for 24 x 4A simultaneous drive, it's just that any channel used in isolation must be able to handle switching 4A at 48V;Needs to operate in ambient environments of up to 55C;Switching MOSFET is the DMNH6021SPDQ :https://www.diodes.com/assets/Datasheets/DMNH6021SPDQ.pdf;(however might be swapped to the IPG20N10S436AATMA1)Minimum switching frequency will be in the range 200-400Hz;Maximum switching frequency will be in the range of 15-20kHz;The only heatsinking method that will be used in this design is copper of the PCB (see page 2 of the datasheet for thermal characteristics). I’m not up to layout yet, but I will be using the 2oz copper, 1-inch square copper plate to achieve a Junction to Ambient thermal resistance of 54C/W;Thank you in advance!

author: daviegravee
author_rank: Newbie
timestamp: October 21, 2024, 01:30:49 am
content: Ah, I didn't realise that LTSPICE wouldn't embed the custom symbol. Here it is (in the .zip, the .asy extension is not allowed by eevblog...)I've also attached a simulation without the gate driver in it.
Request for IC driver suggestion for brushed DC motor - Page 1
Forum section: electronics / projects

author: smd32
author_rank: Newbie
timestamp: March 21, 2023, 02:14:26 am
content: Hi,I am in need of an IC driver for a brushed DC motor that should meet the following requirements:Bidirectional controlPWM speed controlPresence of a heatsink padNo cooling pad on the PCB but the option for attaching a heatsinkContinuous current greater than 2AVoltage flexibility for motor selection (12V or 24V)any suggestions for this ICNot an L298Thank you.

author: H.O
author_rank: Frequent Contributor
timestamp: March 21, 2023, 05:47:04 am
content: L6203, LMD18200 and LB11651 are a couple that are available for thru-hole with heatsink tab. If you can go SMD with cooling via PCB you have dozens to choose from.
Request for PCB Design Review (KiCad) - USB Cable tester - Page 1
Forum section: electronics / projects

author: smaroukis
author_rank: Newbie
timestamp: December 14, 2023, 07:36:31 am
content: I'm looking for some feedback on my first (real) PCB design. It is a USB cable continuity checker with some additional features for testing cable orientation and pulldown/pullup resistors. Looking for layout advice and any gotchas about the fab house requirements (JLPCB).KiCad Files ==>https://github.com/smaroukis/usb-sleuth/PCB Layout Screenshot ==>https://github.com/smaroukis/usb-sleuth/blob/main/attachments/sshot_pcb-viewer.pngSchmatic PDF ==>https://github.com/smaroukis/usb-sleuth/blob/main/38-04-usb-tester.pdfOutstanding questions:- is silkscreen over vias fine? JLPCB list some spacing requirements but I see on other boards the silkscreen just isn't printed- any issues with the ESD diodes on the MCU GPIOs causing issues with testing via DMM during power off (e.g. for testing cable resistors)? I left in isolation switches for this just in case, but not on all pins just one the ones to separate a return path through the MCU GPIO pins (I have some drawings if you're interested).Specs- battery powered- STM32C0 mcu for some logic (cable configuration, Rp/Rd/Ra sensing, etc)- A side: USB Type-A and C- B side: USB Type-C, micro-B, mini-B- 2 layer, front zone = GND, back zone = VCC (see below)- generally SMD with some hand soldering of 0805 components and some THT parts I have on hand (battery holder, power switch)I'm getting it manufactured at JLPCB so if anyone has experience with their capabilities - I used a template for their suggested manufacturing constraints and then double checked with what they had on their website, but I may have missed some things.Top plane is GND since I have more SMD components connected to this net. Bottom is VCC (only powered when on). Should I leave the bottom plane off?Any help is appreciated!

author: tooki
author_rank: Super Contributor
timestamp: December 15, 2023, 03:43:11 pm
content: Quote from: smaroukis on December 14, 2023, 07:36:31 amSilkscreen over tented vias comes out OK (no major gaps, but occasional unevenness), but non-tented vias will produce significant gaps in the silkscreen. I generally use tented vias with a 0.3mm hole and 0.6mm pad. I’ll print silkscreen over them if I have to, but where possible, I’ll move vias around to avoid important silkscreen (or vice versa, if silkscreen position is flexible).Note also that JLCPCB has (at minimum) two different silkscreen processes: inkjet for small runs, true silkscreen for large runs. The inkjet is never as sharp to begin with as the real silkscreening.IIRC KiCad does tented vias by default, so you should be OK, with the aforementioned caveat that I would avoid silkscreening over them where easily possible.
Request for Review - Analog to Digital Board - Page 1
Forum section: electronics / projects

author: kaevee
author_rank: Regular Contributor
timestamp: December 19, 2024, 08:05:59 am
content: I have designed the attached schematic for digitizing analog outputs less than 5V.I am using OPA189 as low-pass filter and ADS8866 16bit ADC.Please review and help me validate the design.

author: Slh
author_rank: Regular Contributor
timestamp: December 19, 2024, 08:45:21 am
content: Not many specifications to review it against there. Do you have a minimum voltage that you want to measure? Eg input range 50mV to 5.0V.An important thing to check is that the common mode input range of the opa189 only goes to within 2.5V of the positive rail so it's only going to work to around 2.5V.

author: kaevee
author_rank: Regular Contributor
timestamp: December 19, 2024, 09:15:16 am
content: Quote from: Slh on December 19, 2024, 08:45:21 amI want to measure 0.5v to 4.5v.Updated for comment on common mode input range: The datasheet says the opa189 is rail-to-rail. But, Vcm Max = (V+) – 2.5. I am confused?

author: moffy
author_rank: Super Contributor
timestamp: December 19, 2024, 09:40:00 am
content: The datasheet:https://www.ti.com/lit/ds/symlink/ads8866.pdfsays that AVDD should be less than 3.6V max preferably 3V, that is what they conducted all their measurements at. The input range is 0V to Vref, so 0V to 5V with your 5V reference. Please refer to the driver circuits on page 27 and 28, it is very important to have that 470pF capacitor right next to the input of the ADC, their recommended driver circuit is a good choice, but you could supply the opamp with a low noise 5V supply, compatible with your Vref.

author: Benta
author_rank: Super Contributor
timestamp: December 19, 2024, 07:03:22 pm
content: Looks OK.One comment: don't use Sallen-Key LP filters for this kind of thing, they're "leaky" at high frequencies.More info here:https://www.ti.com/lit/an/sloa049d/sloa049d.pdf

author: kaevee
author_rank: Regular Contributor
timestamp: December 20, 2024, 01:04:59 am
content: Quote from: Benta on December 19, 2024, 07:03:22 pmWill checkout the document you shared.
Request for review on my open source digital camera project - Page 1
Forum section: electronics / projects

author: Boscoe
author_rank: Frequent Contributor
timestamp: November 21, 2023, 01:26:44 pm
content: Hi all,I would really appriciate some more eyes on my design for this digital camera. I didn't think anyone would be up for doing this however, when I asked some questions on the previous revision due to some issues, multiple members said I should have shared it first. So here we are!The general description and justification for the project is in the google doc link below. I welcome everyone's feedback.https://docs.google.com/document/d/1gnEBzrgK05kzuTFEPspbsJ127sbl_kKvJMLyx1T--wY/The git repo link is below for the electronics. All the other repos are public for the HDL, software etc. The repo names are preffixed with Camera... CameraPMC for power management controller SW for example.https://github.com/gswdh/CameraElectronics/tree/1.2.0Attached is the PDF of the schematic and the Eagle sch and brd files. The board is 8 layers so best viewed in the editor.The tested areas / areas without concern are:- STUSB (USB PD controller)- Battery charger ACT2861- PMC STM32L431RBT- All PSUs- ESP32- Zynq 7000- DDR3 memoryThe areas that are new or of concern are:- The image sensor DDR interface, I have length matched but is the impedance control good enough?- MIPI interface. This is currently being tested on the previous revision and is that last thing to test before ordering this new design.- Native Zynq USB. Previously, I used the FT601Q but was unable to get it to work for Super Speed and any logic in the FPGA. I looked at the FX3 solution however it's not super necessary so I went for a more proven solution that is the USB3320C PHY and native USB 2 of the Zynq. I used a Digilent design as reference here, it will only be used as a device.- Native Zynq Ethernet. I removed the high speed USB interface but still wanted something fast so I added the 1Gb ethernet. This design is based on a Digilent board, too. Interface is 3.3V as the 1.8V variant of this PHY isn't sourcable.Any general feedback would be awesome and I really appreciate any advice given and time taken. I hope this project can also be useful for others in the future somehow, even if it's just because of a library written for this project. I have a passion for simple, re usable code.Thanks!
Request identification IC LFCSP ...  - Page 1
Forum section: electronics / projects

author: max-bit
author_rank: Frequent Contributor
timestamp: January 05, 2016, 10:11:46 pm
content: Request identification IC LFCSP ...Code:H1K#133Package : LFCSP 16 PINOperational amplifier High speed (oscilloscope) ~ 1 GHz ?He works between the IC ADA4817 and behind him is LMH6518 (programmable amplifier)

author: c4757p
author_rank: Super Contributor
timestamp: January 05, 2016, 10:27:44 pm
content: http://www.analog.com/media/en/technical-documentation/data-sheets/ADA4932-1_4932-2.pdf

author: max-bit
author_rank: Frequent Contributor
timestamp: January 05, 2016, 10:33:07 pm
content: Thanks

author: CM800
author_rank: Frequent Contributor
timestamp: January 05, 2016, 10:33:57 pm
content: Quote from: c4757p on January 05, 2016, 10:27:44 pmHow do you actually find that out? / work that out from the small amount of information given? I'm curious.

author: c4757p
author_rank: Super Contributor
timestamp: January 05, 2016, 10:36:38 pm
content: I've used enough ADI parts to be able to recognize their unique QFN style from a mile away. So I went to their website, typed the three-character code H1K into the search box, and quickly checked over the datasheet that came up to make sure it was sensible for the circuit.

author: c4757p
author_rank: Super Contributor
timestamp: January 06, 2016, 04:33:28 am
content: Yep, with a slight ledge between the top and bottom halves as well.
Request: Project power budgeting / power calculation tool examples - Page 1
Forum section: electronics / projects

author: TileSeeker
author_rank: Newbie
timestamp: January 15, 2024, 12:00:44 pm
content: Hello. I am currently working on a project with many different components on several different power rails and made a quick calculator for estimating total power consumption.My calculator is very simple:I list the major components and how much current they consume on what voltage rail. Then I sum the current on each rail, add the regulator efficiency and sum the different rails.There are a few areas that could use improving.- Adding duty-cycling to include module activity.- Having regulator efficiency be a function of current and temperature for greater accuracy.- Adding tables for better graphicsI was wondering how other people like to do this and if they had any nice tools or templates they would recommend me take a look at.
Request reliable source for UDN6118A VFD driver parts - Page 1
Forum section: electronics / projects

author: rfdes
author_rank: Regular Contributor
timestamp: October 07, 2022, 08:28:33 pm
content: I need 6 pieces of this part and see that they are available all over the web. The question, of course, is 'who can I trust?'Has anyone purchased these parts recently and have a suggestion for a trustworthy source?Maybe there is a modern replacement for this part that someone might suggest.ThanksJim
REQUEST Sperry HZ-6 Horizon Flight Dir. Pinout or Service/Overhaul Manual - Page 1
Forum section: electronics / projects

author: obsoletepower
author_rank: Contributor
timestamp: June 15, 2022, 01:34:19 am
content: Hello fellow hobbyists,I'd like to build an interface between my Sperry HZ-6B Horizon Flight Director Indicator and MSFS 2020 but I cannot seem to find the pinout for the two connectors in the back. If anybody out there has a service manual for this component or has a snippet showing the pins and their function and willing to share that with me that would be amazing. I don't want to take it apart to try and reverse engineer it because technically it is still airworthy and if I cannot successfully do this then I might just sell it. I have the FAA docs and last overhaul tag.
Requesting a second set of eyes on a power supply design - Page 1
Forum section: electronics / projects

author: Esquared
author_rank: Contributor
timestamp: November 22, 2021, 11:32:21 am
content: Hello, I have designed what I think is a functional power supply (dual tracking mains isolated +/-21 Volts, 1.5Amps). I would really appreciate some experienced eyes on the design I made in LTspice. From the waveforms, I think everything should be in order; but this is the first time I've designed a power supply so I don't know if the simulation is hiding problems that I'm not aware of. Some more focused questions I have are:I have paralleled the LT3081's and LT3091's as per the datasheet suggestions, but I'm unsure if this is necessary. I just didn't like the idea of running the regulators at max outputI have no good ideas about the current limit potentiometer situation and I am trying to avoid dealing with digital pots and microcontrollers if possibleI was planning on 3D printing the enclosure for the project possibly. Would the only things that I need to earth be the transformer and the external earth jack? Since the case would be plastic?
Requesting help in reviewing my relay driver circuit - Page 1
Forum section: electronics / projects

author: polar8
author_rank: Contributor
timestamp: August 26, 2013, 06:01:17 pm
content: Hello,I've designed this circuit that will allow me to drive a CPC1718 solid state relay with my BeagleBoneBlack (3.3V IO). I'm fairly new at this, and I calculated the components based on some tutorials I found online. Would you mind taking a look at my calculations and letting me know what I should change?Thanks!

author: SeanB
author_rank: Super Contributor
timestamp: August 26, 2013, 07:14:25 pm
content: Use 1k and 10k for the transistor and pull down, as the gate drive will have some loss. The resistors for the LED and SSR can both be 56R, slightly higher current but with the higher current from 2 LEDS the transistor will be a little higher in Vce. Basically they will likely cancel out. It will work.Just remember to have adequate clearance and creepage distance across the SSR device or you will blow up your micro at some point.

author: Paul Price
author_rank: Super Contributor
timestamp: August 27, 2013, 06:22:39 pm
content: The optoisolator current and LED indicator current don't cancel out, they add together.

author: penfold
author_rank: Frequent Contributor
timestamp: August 27, 2013, 06:50:10 pm
content: Based on the data sheet, would be a touch cautious of your range of input current, it comes across to me that the absolute maximum of 100mA is really right at the edge of what the LED is capable of, there is a little side note by the recommendation of 10mA that for higher loads and temperatures 20mA is recommended, so based on that my inclination would be towards a drive current of 15mA or so.I would also consider the fact you have selected a drive current for the SSR somewhat higher than the happy minimum suggested when selecting the safety factor for the Ib saturation current, you could probably get away with half the base current.Other than that, it would work for a one off in a circuit, but it would start getting pretty juicy (without revising the design) if you had many of them