hybridfree/eevblog-posts huggingface dataset:
Raspberry pi OpenOCD flashing two device at the same time - Page 1
Forum section: electronics / projects

author: jealcuna
author_rank: Contributor
timestamp: September 29, 2021, 09:44:01 pm
content: I recently realize that it is possible to use raspberry pi as a flash/debugger for arm mcus by using OpenOCD which implement Serial Wire and Jtag protocol with bitbanding.So, I would like to make a cape for raspberry pi in order to flash more than one device at the same time, but I don't know if there is some constraints due bitbanding technique.Dear linux/folks experts, have you experiment flashing more than one device at the same time by using openocd in raspberry pi?
Raspberry Pi RGB PWM Controller - Help! - Page 1
Forum section: electronics / projects

author: XL5
author_rank: Contributor
timestamp: December 12, 2013, 09:44:05 pm
content: A bit of backstory: I have a 19" cabinet that has a strip of RGB LED's in the top, at the moment they are just soldered directly to a power supply that means they are always red. The ups supports SNMP, as do a number of other devices, and I think it would be cool to change the colour of the lights according to the status of things. They could go red if a server is down, or white if there's a power cut, so that I can see better.The controller needs to be networkable, and be capable of controlling 3 channels of PWM independently. At the moment I'm planning to use a raspberry Pi. Obviously the Pi doesn't have enough juice to run a 12V LED strip like this, so some sort of transistor based device will have to do that work.I'm thinking of designing a board that will plug onto the GPIO pins and have all the necessary components on it. It would take a 12V power in and using transistors it could power the LED's based on output from the GPIO.If I'm putting a board on the Pi that will take 12V it makes sense to also use that 12V power supply to power the Pi, so I think I should put on some sort of regulator down to 5V and include a USB port to plug the pi into.Anyway, this is as far as I have got, and I need some guidance...

author: filip_cro
author_rank: Regular Contributor
timestamp: December 12, 2013, 09:52:55 pm
content: Doing it with FETs/MOSFETs may be easier. Use transistor to connect LEDs to GND. (open collector or open drain)Is Ri Pi 5V output? Maybe you will need to use drivers.For 12V to 5V use switching mode power supply. Linear regulators wont be able to do 3.5 W (0.5A x 7V) without heat sink.

author: XL5
author_rank: Contributor
timestamp: December 12, 2013, 09:56:41 pm
content: Quote from: filip_cro on December 12, 2013, 09:52:55 pmThank you for your response. Though, I think you'll have to dumb it down a bit for me. Sorry!Where would I put MOSFETs? I didn't understand what you said about transistors..Could I use multiple regulators to spread the load and generate less heat on one component? Otherwise, what would a switching power supply involve?

author: filip_cro
author_rank: Regular Contributor
timestamp: December 12, 2013, 10:02:22 pm
content: NPN (N-MOSFET)E (S) to GNDB (G) to Ri PiC (D) to LED cathode+12V to led anode

author: XL5
author_rank: Contributor
timestamp: December 12, 2013, 10:03:39 pm
content: Ah, that makes sense, very similar to the transistor.
Raspberry PI - SPI HAT (w/Dual SPI bus and voltage) - will it work ok? - Page 1
Forum section: electronics / projects

author: pickleit
author_rank: Contributor
timestamp: May 31, 2019, 07:49:53 pm
content: HiI would like the communities comments on whether or not the my design for a raspberry pi SPI breakout HAT; actually works.The board has the following features:1) Both SPI buses are broken out to 8 way 0.1in pitch dupont unshrouded headers.2) each SPI bus has a switch to switch the working voltage between 3.3V and 1.8.How it should work:If the switch is set to 3.3V, the MOSI, MISO, SCLK, CS pins go to a "Quad SPDT Analog Switch" then direct to the 8-way header.If the switch is set to 3.3V, the MOSI, MISO, SCLK, CS pins go to a "Quad SPDT Analog Switch" then to a "Bidirectional Voltage-level Translator", then on to the 8-way header. Also the 3.3V from GPIO pins goes to a Voltage regulator.Also, for protection, there are 100nf caps across the 3.3v & GND and 150 ohm resistors on each of the MOSI, MISO, SCLK, CS pins.Please let me know if there is anything I could do better; and more importantly, does my design work?I have attached the schematics and a board image. Both the schematic and board image are licensed: CC BY-NC-SA 4.0
Raspberry Pi to control "TM1809" chip daisychain - Page 1
Forum section: electronics / projects

author: David1988
author_rank: Newbie
timestamp: May 29, 2013, 01:20:13 pm
content: I recently acquired a sizeable amount of stringed R-G-B LEDs utilising the TM1809 chip only I did not receive the controller "box" to send the signal/data.Could I program the Raspberry Pi to send this data required for the chips to do anything to the LEDs.Sorry I will need detailed instructions on how to program the RPi if what I ask is possible, I have NEVER done this before.Image of the chip and how it is used on the boardDatasheet on the chip

author: Strada916
author_rank: Frequent Contributor
timestamp: May 29, 2013, 03:32:43 pm
content: Reading the data sheet. You send 72 bits of info. First word of 8 bits is one colour and it's brightness. 8 bits = 255 levels. Maybe try it on an Arduino first?

author: David_AVD
author_rank: Super Contributor
timestamp: May 29, 2013, 10:49:45 pm
content: Are you stuck on using a Pi for this? There's plenty of pixel controllers out there at reasonable prices.
Raspberry Pi TTL/CMOS comparator project.  - Page 1
Forum section: electronics / projects

author: okney1lz
author_rank: Contributor
timestamp: September 22, 2018, 10:33:46 am
content: Just going to leave this here, looking for some insight/opinions on viability of such a project.https://www.reddit.com/r/raspberry_pi/comments/9hukfl/ttlcmos_comparator_project/?utm_source=reddit-android
Raspberry Pi USB Type C HUB  - Page 1
Forum section: electronics / projects

author: enutilenergy
author_rank: Newbie
timestamp: August 31, 2016, 01:25:41 pm
content: Hello, we have put together an awesome USB type C Hub to connect with the Raspberry Pi. Have a look athttps://www.kickstarter.com/projects/722780906/pichub-usb-type-c-hub-for-raspberry-pi-and-pizero. Also integrates a microcontroller and allows power on the fly switching with a USB Type C adapter providing 3A of power. Thks!
Raspberry Pi v2 Mod B Pinout - Page 1
Forum section: electronics / projects

author: pighixxx
author_rank: Contributor
timestamp: June 25, 2015, 02:34:18 pm
content: FinallyDownload athttp://www.pighixxx.com/test/2015/06/raspberry-pi-v2-mod-b-pinout/

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: June 25, 2015, 05:43:32 pm
content: thats really nice!

author: suicidaleggroll
author_rank: Super Contributor
timestamp: June 25, 2015, 08:38:12 pm
content: It looks nice - however there's no orientation marker on the 40-pin header, either on the CAD drawing of the board or on the pinout diagram. Since the diagram is rotated 90 degrees versus the CAD drawing, there's some ambiguity there.edit: actually it looks like there is a TINY chamfer on the corner of the header, but it's almost impossible to see. Maybe just make pin 1 a different color so it jumps out at you?

author: rollatorwieltje
author_rank: Unknown
timestamp: June 26, 2015, 12:41:13 pm
content: The absolute maximum of 50mA is not just for the IO pins, but for the entire 3.3V power rail. Would be nice to add that as a warning.If you need 3.3V for anything serious you need to use the 5V rail and provide your own regulator. This almost got me when I was designing a board with a 3.3V GPS module.

author: pighixxx
author_rank: Contributor
timestamp: June 28, 2015, 08:33:11 am
content: Thanks to all,in the next revisione i make the suggested changes.
Raspberry Pi weekend project - Page 1
Forum section: electronics / projects

author: Ment11
author_rank: Contributor
timestamp: February 28, 2013, 01:03:59 am
content: I finally received my Raspberry Pi last Friday, and decided to build a computer out of some spare parts I had laying around. I used a CRT viewfinder from an old Sony camera as a monitor, and powered the whole thing from two 11.1V Li-Po's running in parallel. For the Raspberry Pi power supply I just used a simple LM7805 regulator.I wired up a character LCD to the Raspberry Pi GPIO as well, but unfortunately could not get it working yet. (if anyone knows how to properly interface it please let me know) I still want to wire up a USB hub to it so I can run a wireless card, and build a proper power supply with charging capabilities on board.If anyone is interested I have more pics, and a more detailed write up on my web site -http://overclocked.tv/diy-projects/pifinder-raspberry-pi-portable-pc-project

author: ivan747
author_rank: Super Contributor
timestamp: February 28, 2013, 01:48:27 am
content: That's quite an odd monitor! Did you use composite video to interface it?

author: Ment11
author_rank: Contributor
timestamp: February 28, 2013, 01:52:21 am
content: Quote from: ivan747 on February 28, 2013, 01:48:27 amYes, I just wired an RCA jack into the original Viewfinder connector, and connected that to the Raspberry Pi analog video out. For power I just wired the viewfinder straight to the batteries (it runs from about 10v to 13v).

author: psycho0815
author_rank: Regular Contributor
timestamp: February 28, 2013, 08:24:27 am
content: How exactly did you connect your lcd, i can't make that out in the picture?The Pi's GPIO-Pins work with 3.3V-logic. Most LCDs need 5, so you need some sort of Levelshifting. Since it's only unidirectioal you can use simple transistors or a darlington array depending on what you have lying around. As for the software, there's plenty of information on accessing those LCDs. Not sure if anyone has already written a library for the Pi.

author: Ment11
author_rank: Contributor
timestamp: February 28, 2013, 02:08:56 pm
content: Quote from: psycho0815 on February 28, 2013, 08:24:27 amThe lcd is connected to the Pi straight through, but in read only mode.(R/W pin grounded) The power comes from the 5V regulator. There is a library already written,http://learn.adafruit.com/drive-a-16x2-lcd-directly-with-a-raspberry-pi/overviewso all the hard work was already done. So far from what I checked out it's either a python script not running properly, or the LCD is not wired properly. I have a scope with a logic analyzer at work, so I am probably going to check it out when I get some time.
raspberry pi zero activity led - Page 1
Forum section: electronics / projects

author: Avi
author_rank: Contributor
timestamp: June 15, 2017, 11:15:46 am
content: I have A raspberry pi zero W, and would like to put it in this official casehttps://images-na.ssl-images-amazon.com/images/I/61SH0gSIFSL._SL1000_.jpgI would like to be able to see the activity LED so I can tell:when it has completed booting upthat things are even running or it's just sitting idlewhen it has competed shutting down so I know it is safe to remove powerThe issue is that this LED is nowhere near the lid hole (its near the bottom right screw hole) and it is a sideways emitting (towards the bottom edge) surface mount LED.I would rather not do any soldering or desoldering if at all possible.I don't want to waste an IO pin, and also muck around with recompiling the kernel.as far as I can tell the circuit is 3.3v -> 470 ohm -> LED -> somewhere. None of the test pads seem to go to the other side of the LED so that not an option.Is anyone aware of a suitable lightpipe I could use? otherwise, an alternate solution? (not involving a light sensor!)

author: Jeroen3
author_rank: Super Contributor
timestamp: June 15, 2017, 11:37:56 am
content: Glue on a bit of fiber from those lights.You can get the fiber at lighting stores or ebay for "star sky ceilings".https://en.wikipedia.org/wiki/Optical_fiber#/media/File:Use_of_optical_fiber_in_a_lamp..JPGforum can't handle # in urls

author: X
author_rank: Regular Contributor
timestamp: June 15, 2017, 11:49:18 am
content: For AU$12, you can drive over to the greatest electronics store in the history of the universe and findLED light guides.Alternatively perhaps bending some acrylic rods may work, but I've found this technique to depend on the actual material/colour of the rod itself. Try and get one that you can see through end-to-end, maybe even coat the rod in silver paint to improve total internal reflection.
raspberry pi2 test-bed (fancy psu stuff) - Page 1
Forum section: electronics / projects

author: linux-works
author_rank: Super Contributor
timestamp: March 06, 2015, 10:37:22 pm
content: wanted to play around with the pi2 board and so I threw together a test bed to let me tinker around.I'm using a spare copy of a chassis I designed for another pi project.the modules are:top-left: a low voltage UPS module that gives fast fail-over from one dc-in to another. normal use will have 18vdc on one jack and a battery at 12v on the other. when 18v is present, it charges the batt and drives the output of the module. when absent, power from the module comes from the batteryllower-left: dc/dc converter. I can get either 18v or 12v out of the UPS module; but the pi wants 5v. so, this module does that efficiently and without any appreciable heat.middle: simple $5 ebay 2 wire voltmeter. its nice to monitor the dc line voltage on test beds.bottom-right: neat little sd-card (or micro) extender. lets me do a right-angle turn and with the side of the box on, the card hangs out an open slot and I can swap out its o/s 'disk' whenever I want.upper-right: the pi2, of course.almost all came from amazon. parts, for those who care:UPS module:http://www.amazon.com/gp/product/B005TWE4Q0/dc/dc:http://www.amazon.com/gp/product/B00MEFJXM02 wire voltmeter:http://www.amazon.com/Digital-Voltmeter-3-00~30V-Motorcycle-Battery/dp/B00R5YAM5Csd card remoter:http://www.amazon.com/gp/product/B00L9OB7WQrpi2:http://www.amazon.com/Raspberry-Pi-Model-Project-Board/dp/B00T2U7R7Ipower for the pi has always been a problem, of sorts, so I kind of oversolved it, to some degree, I guessI'm putting 5v directly onto the board and bypassing the usb connector.before I did this, I did try the board standalone with a usb micro cable. I saw the power led blink on and off during some heavy loading, so there are still some issues with the onboard psu and relying in usb power from a computer or wallwart.anyway, there's my test bed and parts list in case anyone likes the idea and wants to replicate it. the UPS module works well if you have a 12v sla battery on one pair of wires and an 18v laptop brick supplying power to the other pair. I might see if I can find a small enough 12v battery so that it can sit right inside this chassis.
Raspberry Pico trouble with utime  - Page 1
Forum section: electronics / projects

author: Renaud F5ZR
author_rank: Contributor
timestamp: August 04, 2025, 04:59:46 pm
content: Hi everybody,I'm new to Pico and Python.In a new program I have now some utime error.So I went back to something very simple:from machine import Pinimport utimeLED = Pin(1, Pin.OUT)while True:LED.value(1)utime.sleep(1)LED.value(0)utime.sleep(1)And indeed it doesn't work and I get:Traceback (most recent call last):File "<stdin>", line 6, in <module>KeyboardInterrupt:This of course worked perfectly before. I resetted the Mac and the Pico to no avail.Any help will be much appreciated.RenaudModify message

author: ejeffrey
author_rank: Super Contributor
timestamp: August 04, 2025, 05:25:09 pm
content: QuoteWhen? How?did you press ctrl-C? That's what keyboard interrupt means.

author: Renaud F5ZR
author_rank: Contributor
timestamp: August 05, 2025, 05:41:39 am
content: The Pico is connected to the Mac and driven by Thonny.That little led test program did before what it should. Now it does nothing so I stop it and get the:Traceback (most recent call last):File "<stdin>", line 6, in <module>KeyboardInterrupt:

author: ejeffrey
author_rank: Super Contributor
timestamp: August 05, 2025, 06:08:34 am
content: Ok so it sounds like the actual problem is probably that utime.sleep() is blocking forever. The keyboard interrupt is just you stopping it because it's not doing anything.Does anything else work? Like just setting the LED once? Printing variables?I'm not sure how micro python works internally but maybe the timer interrupt is disabled so the RTC isn't advancing? Or maybe there is a system clock frequency parameter that needs to be set?One thing to check would be to call utime.ticks_us, then do a short manual delay loop and call ticks_us again and see if the value is different.

author: Renaud F5ZR
author_rank: Contributor
timestamp: August 05, 2025, 06:21:48 am
content: I did more tests since.utime is not the culprit as this doesnt light the led either:LED = Pin(1, Pin.OUT)LED.value(1)I tried GP2 too (pin 2) wondering if the port was dead, also nothing, but moving the +led to +3.3V lights it.

author: Renaud F5ZR
author_rank: Contributor
timestamp: August 05, 2025, 07:46:12 am
content: And I forgot to say that indeed other programs, non GPIO, works.

author: Renaud F5ZR
author_rank: Contributor
timestamp: August 07, 2025, 06:55:18 pm
content: Hi,This topic was moved there:https://www.eevblog.com/forum/microcontrollers/raspberry-pico-trouble-with-utime/msg6000283/#msg6000283
Raspberry pizero W wifi antenna orientation question. - Page 1
Forum section: electronics / projects

author: jdolecki
author_rank: Contributor
timestamp: February 19, 2021, 01:29:59 pm
content: I have PCB project and have the Pi WZero plugging into another circuit board.Since I can add the Pi header to the top or bottom do the WIFI signals affect the other board circuits?Does the wifi signal only radiate from the top of the antenna and do not pass through the Pi board?I hope I explained that correctly?Thanks John

author: Ian.M
author_rank: Super Contributor
timestamp: February 19, 2021, 02:06:51 pm
content: https://magpi.raspberrypi.org/articles/pi-zero-w-wireless-antenna-designIts basically a loop antenna. There is a trapezoid shaped cutout in the ground plane, both sides and heavily via stitched round its perimeter, with its short side at the board edge, consisting of two series caps driven by the feedline. There's another capacitor from the feedline to the groundplane a short distance back along it, presumably for impedance transformation to match the loop to the feedline.It will certainly radiate both sides of the board and with a peak EIRP of 49mW#*may* affect susceptible circuits on nearby boards.#https://www.raspberrypi.org/documentation/hardware/raspberrypi/compliance/rpi_DOC_ZeroW_CANADA.pdf
RasPi Compute Module Retro Gaming Project - Page 1
Forum section: electronics / projects

author: chronic8000
author_rank: Newbie
timestamp: June 18, 2019, 08:39:00 am
content: I don't know if anyone is into their retro gaming here on the eevblog forums but I am seeing a lot of cheap, crappy original Gameboy clones on eBay and aliexpress and all of them are underpowered and rubbish. People try putting a raspi zero into the Gameboy dmg-01 cases which works better but we now have the raspberry Pi 3B+ on a single "compute module" which would be perfect for sticking inside the dmg-01 Gameboy (picture attached) and designing a replacement PCB for the Gameboy which would sit where the original PCB goes but also houses the pi board and has attachment to a modern LCD. This could be a slick solution for other people designing portable Gameboy pi machines and could easily be stuck on Kickstarter or similar to get into production but I am, despite watching nearly every eevblog video no good at PCB design so I thought to come over to the eevblog and see if we cant assemble some people together and maybe get this project off the ground. I am not looking to get rich off of it just want to get a decent product designed so if anyone has any free time and is good at PCB design get in touch! Using the compute module would mean the thing could easily be upgraded to the compute module 4 when it is released just like upgrading a stick of ram but would require very good skills to get the PCB designed. Don't even *have* to use the dmg-01 case but it is iconic and cheaply available even in lots of different colours and could quite easy be a drop in replacement PCB.

author: JJalling
author_rank: Unknown
timestamp: June 18, 2019, 09:15:58 am
content: I'm not sure that the compute module is suited for a battery powered application. The recommended powersupply is 250mA on both the 1V8 rail and the 3V3 rail.BR Jonas

author: chronic8000
author_rank: Newbie
timestamp: June 18, 2019, 09:20:47 am
content: Quote from: JJalling on June 18, 2019, 09:15:58 amYeah it is can get 6000mah battery. Even if a custom case has to be designed. It would mean the system is fully upgradable as future compute modules will have the same form factor. Need a DC-DC converter capable of providing 1.5amp+

author: chronic8000
author_rank: Newbie
timestamp: June 18, 2019, 10:16:49 am
content: https://workspace.circuitmaker.com/Projects/Details/philip-sempers/Gamepi

author: JJalling
author_rank: Unknown
timestamp: June 18, 2019, 10:48:50 am
content: Here is a similar project:https://hackaday.io/project/94791-retro-cm3-a-powerful-retropie-handled-game-consol

author: chronic8000
author_rank: Newbie
timestamp: June 18, 2019, 11:05:59 am
content: Ah ok didn't know there was already one. Suppose if you think of it then it's probably already been done lol.
Raspi Pi & Cam Project + Timelapse Video - Page 1
Forum section: electronics / projects

author: noSun
author_rank: Contributor
timestamp: August 19, 2015, 03:40:16 pm
content: Finished another project....The video features 3D printing, assembly, and timelapse video.

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 19, 2015, 04:04:17 pm
content: Lovely ! Lovely !Now, to over-impress everyone, if you look for a new project, just add a stepper motor controlled by the arduino. Then either pan the camera, or, better, put it onto a track, so that it moves as a camera moves along the track, but everything timelapse. It's very impressive and the next brilliant step for you to take.

author: noSun
author_rank: Contributor
timestamp: August 20, 2015, 08:47:39 pm
content: Quote from: TheElectricChicken on August 19, 2015, 04:04:17 pmthank ya
Rate My Bodge - Page 1
Forum section: electronics / projects

author: Finnaaah
author_rank: Contributor
timestamp: April 11, 2024, 01:12:57 am
content: I forgot to change footprint when changing componentsthis is my attempt at converting two VSSOP-8 footprints to fit SOP-8. Obviously not a permanent solution, I just wanna see it workDon’t worry, I’ve electrically tested it and somehow everything is making good contact and nothing is shorted

author: prosper
author_rank: Regular Contributor
timestamp: April 11, 2024, 08:04:41 pm
content: Not the prettiest, but if it works...I'd probably have bent the pins up, glued the part down nearby but not on top of the pad, and used fly wires. That way I can still access the pads if I need to touch something up. Then a few daps of superglue to keep everything secure

author: Finnaaah
author_rank: Contributor
timestamp: April 12, 2024, 02:37:23 am
content: I was shocked, but it did workI’ll probably redo it some time this weekend how you said, seems like a cleaner approach.
Rate my thermostat design - Page 1
Forum section: electronics / projects

author: Rachie5272
author_rank: Regular Contributor
timestamp: December 13, 2014, 03:13:00 pm
content: This is my first attempt at making a prototype circuit for what will hopefully become a commercial product. The application is a small kitchen appliance, which is little more than a heating element with a thermostat and a graphical oLED display.The microcontroller is basically an arduino setup for ease of programming and testing. I'll probably switch to a cheaper micro eventually, but this is the easiest way to get the display running.For the power supply filtering capacitors, I'm using four 10 uF multilayer ceramics instead of the conventional electrolytic (heat sensitive) or tantalum (conflict mineral). Is this crazy?I'm more concerned about the high voltage side. I went with a TRIAC instead of a relay for silent operation, and the zero crossing optoisolator means the lights in the room won't flicker when the heater turns on. I'd very much like to move the bulky transformer off the PCB, but I have no idea how to source one with leads and a connector attached to it.The mains fuse, thermal fuse, and thermal circuit breaker aren't shown.Any comments on my design? Hopefully it's not too bad.
Rated maximum voltage of the boot strap capacitor of a high-side mosfet driver - Page 1
Forum section: electronics / projects

author: eneuro
author_rank: Super Contributor
timestamp: March 16, 2015, 09:09:13 pm
content: Hello,I'm looking for your opinion on rated maximum voltage of the boot strap capacitor of a high-side mosfet driver.In this example (classic) bootstrap circuitfrom this link:http://electronics.stackexchange.com/questions/87650/what-must-be-rated-maximum-voltage-of-the-boot-strap-capacitor-of-a-high-side-mothere is conclusion:QuoteNo question about it that:QuoteBut, really do we need HV boot strap capacitor of a high-side mosfet driver?Just put into simple circuit simulator 12Vcc and simulated overvoltage on half-bridge mosfet source in the middle with lets say 24V spike and no way there were no more than 12V on boost strap caps in high sideUpdate: Ups, probably on this optoisolated gate driver PSU (left battery) should be also power rail rated diode blocking possible higher voltage spikes througth zeners...In this simple H-bridge I plan to use a few the same simply optocoupler insulated low speed low current gate drivers and 16V 100uF boost strap caps since I do not knowhow is it possible that those caps will be charged to higher voltage than 12V since I've additional 12V zenersRead quite nice intros howto calculate needed capacity, but there is nothing about boot strap capacitor rated maximum voltagehttp://www.ixysic.com/home/pdfs.nsf/www/AN-400.pdf/$file/AN-400.pdf

author: JohnnyBerg
author_rank: Frequent Contributor
timestamp: March 16, 2015, 09:12:24 pm
content: Looks like a IRF2110 to me.It is in thedatasheet:Gate drive supply range from 10 to 20VThe reverse breakdown of the diode is High side voltage minus VCC

author: nctnico
author_rank: Super Contributor
timestamp: March 16, 2015, 09:15:40 pm
content: The bootstrap capacitor should not need to provide a higher voltage than the maximum gate voltage. 20V is the maximum you can expect and often the voltage is much lower. One thing to watch out for is the dielectric of the bootstrap capacitor. If it is not NPO of COG the capacitance may drop radically with several Volt applied. So you may need a capacitor rated for 50V or more to meet the capacitance requirements.

author: eneuro
author_rank: Super Contributor
timestamp: March 16, 2015, 09:31:38 pm
content: Quote from: nctnico on March 16, 2015, 09:15:40 pmThank you for this hintI can easy put 25V caps in those cheap simply gate drivers, while it is not part of any critical systems and 50% duty cycle-no sinusoidal waveforms-pure ON/OFFProbably even 10uF caps are overkill there when estimated this needed capacitance and played a little bit in circuit simulator
Rattiest current datasheet? - Page 1
Forum section: electronics / projects

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 06, 2014, 03:13:34 am
content: What's the rattiest (for foreign readers: shabby, old, dirty) data sheet you've seen for a current production part?My vote:http://www.digikey.ca/product-detail/en/62PC8F/SC1536-ND/1289085

author: calexanian
author_rank: Super Contributor
timestamp: August 06, 2014, 03:19:03 am
content: Oh, that don't even come close. If you will notice on the left side its a customer drawing. Also it was made in 82 by the looks of it. Well before CAD was commonplace. Many perts don't even have spec sheets.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 06, 2014, 07:33:39 am
content: The Chinese ones that are current (written on a computer) but awful (probably written in Word, by ESL writers) are pretty annoying.Think one of the oldest datasheets I've seen dates back to release rev in 1968 or something like that. More and more revs added over the years, but the same basic part (or part series). Some Molex connectors are like that. Hand drafted? Who cares. As long as the scan is good (the above example, not so much..), the drawings themselves are usually correct and understandable.Tim

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 06, 2014, 05:31:14 pm
content: Yikes, the oldest databook I have is a 1968 Motorola ECL databook, and it looks cleaner!

author: wraper
author_rank: Unknown
timestamp: August 06, 2014, 08:41:43 pm
content: My favorite is this one.http://www.farnell.com/datasheets/318408.pdfhttp://uk.farnell.com/uv-tec/140-1r/bezel-filter-red/dp/175705

author: calexanian
author_rank: Super Contributor
timestamp: September 11, 2014, 10:36:27 pm
content: Quote from: wraper on August 06, 2014, 08:41:43 pmI have still seen worse. Far worse.

author: BillWojo
author_rank: Regular Contributor
timestamp: September 12, 2014, 02:46:11 am
content: I looked at all the data sheets shown, nothing wrong with any of them. Is it because you expected to see a cad drawing? I don't get it.BillWojo

author: calexanian
author_rank: Super Contributor
timestamp: September 12, 2014, 04:19:20 am
content: Thats just a part drawing really. Not a data sheet. Thats just what they looked like before computers were everywhere. I have looked through many upon many file cabinets full of drawings like that and have never found them lacking.Kids....
Rc brushless motors - Page 1
Forum section: electronics / projects

author: Ace192
author_rank: Newbie
timestamp: December 21, 2017, 12:44:04 pm
content: Hey folks,I’ve seen bicycles using rc motors for electric bike mods... could this be extended to motorcycle ev conversion by having multiple motors or would they realistically overheat and melt down? I’ve seen water cooled jackets for brushless inrunners??
RC car Motor help - Page 1
Forum section: electronics / projects

author: ironasona
author_rank: Newbie
timestamp: March 04, 2021, 10:09:12 pm
content: I was told to make a RC car that can go vertically up a 180 degree angle tube , 2m , and i wanted to ask what type of motor would i need to be able to do that ,car weight is 600grams. or is there a calculation for that .ty )

author: fordem
author_rank: Regular Contributor
timestamp: March 04, 2021, 11:01:59 pm
content: What's a 180 degree angle tube? My grandson has a couple of toy cars, they are remote controlled cheapies, they'll drive up a flat vertical surface (which is what 180 degree angle means to me) , they'll even drive across a flat ceiling.

author: ironasona
author_rank: Newbie
timestamp: March 04, 2021, 11:07:34 pm
content: sorry i meant to say a RC car that can climb a vertical tube in a 0.145m diameter tube

author: Zero999
author_rank: Super Contributor
timestamp: March 05, 2021, 01:24:16 pm
content: How fast?The motor and gearbox, just needs to provide a force of f = mg, on the outside of the tyres, where m is the mass in kg, 0.6kg in this case, and g is the gravitaional acceleration of the earth: typically 9.8N, giving 0.6*9.8 = 5.88N.Suppose the car needs to travel at 2m/s. P = f*s = 5.88*2 = 11.76W.In reality there will be losses, so the motor and any electronics driving it, will need to be rated to much more power.

author: fordem
author_rank: Regular Contributor
timestamp: March 06, 2021, 11:29:18 am
content: As I mentioned, my grandson has a couple of toy cars, that are capable of driving up a flat vertical surface, or even across the ceiling - they're powered by two AA cells, I don't see AA cells lasting very long powering an 11.76W load.The challenge as I see it, is maintaining sufficient traction - the car can't climb the wall unless it has sufficient traction - my grandson's toy does it through what can be considered a "reverse hovercraft" principle - a thin flexible rubber skirt just long enough to bridge the gap between the chassis of the car and whatever flat surface it's on, and a fan to create a vacuum to pull the car against the surface.The weight of the vehicle is obviously going to be a critical factor.Is RC Remote Controlled or Radio Controlled? My grandson's toys are radio controlled, so self contained, but you can do remote controlled using a wired controller which would enable you to put the power source in the controller, thus reducing the weight.
RC Car Toy Modification Help !!! - Page 1
Forum section: electronics / projects

author: battery13v
author_rank: Contributor
timestamp: December 23, 2016, 11:49:35 am
content: Hello everyone !!!i have this 2 RC car toys in the junk ... so i have the idea to modify them into one car that has much power and speed .... So i reassemble them into one frame and i got this one :*******************-------------------------*******************This new Toy contain 2 DC motors in the Rear and One Steering Dc Motors in the front ...the old circuits contain just 2 H-bridge for 2 Dc motors, when i test it one H-Bridge is Burned out cause i connect it to 2 Rear Dc Motors, So i figured out that i have to add a new H-Bridge to my second rear Dc Motor ... The demodulator is a chinese clone of the RX-2 Chip ... When i tested it's output i found that it output pulses (when i trigger forward it generate a positive pulse ... and when i release the forward trigger, it generate a negative pulse ) and with this pulses it make the DC Motors Runs .... So i searched in the Internet and i figured out that it could be a latching circuit after this pulses ... However when i retrace the Circuit i did not found any LAtching Circuit ... So this is my problem and i want someone to tell me how this thing "Chinese RX-2 Chip" control the DC motors with Pulses??*******************-------------------------*******************You will Found in the attachement the circuit schematic of the H-Bridge*******************Here is a video about the result of the oscilloscope in the output of the left and right ouptut pin signalhttps://sendvid.com/hguz65wg*******************So i want to know how this thing make a dc motor turn on ??How could i make another H-Bridge that trigger on with this kind of pulse for my Third DC Motor ??Thx ??

author: taustin
author_rank: Contributor
timestamp: December 28, 2016, 06:08:18 pm
content: Your description was a bit hard to follow, but I think I get the jist of what you want to do.First, the motors are likely driven with Pulse Width Modulation (PWM). There is lots of information online if you don't understand what this is.Basically it turns the power on and off very fast to control the speed of the motor.The H-bridge allows the PWM signal to drive the motor forwards or backwards. Please forgive me if you already understand this, but it is important to understand.The H-bridge is likely cheaply designed so it cannot handle much more power than the one motor it was designed for. You may be able to add another motor to the output, but it may cause the FETs to fail. If this is the case, you can look into replacing the FETs with higher power ones, but be aware than there are likely two different FETs used in each H-Bridge. If you do some reading on PWM and H-Bridges you will be able to understand this and choose some good replacement FETs that can do what you want. One last thing - make sure you use heat sinks on the FETs as they can get quite hot fairly quickly.Good Luck!
RC Circuit? Confirm my educated guess - Page 1
Forum section: electronics / projects

author: cbassett1000
author_rank: Contributor
timestamp: October 01, 2019, 05:52:19 am
content: Below I have an ASCII schematic I am trying to figure out what it does, specifically to the signal wires. I am thinking some sort of RC circuit, maybe a band pass filter of sorts? It does not affect the signal when measuring DC, AC measurement has not been tested. The circuit goes parallel into the S1 and S2 wires. S1 and S2 are DC leads (less than 20 volts) but *may* have AC noise in them. S1 and S2 may or may not be floating reference to ground. I cannot give much further information due to NDA. Thanks!|||S1-Signal Positive/S2-Signal Negative/R1-20.5k/R2-500k/C1-1uF/C2-2uF||| || "T"-Obvious/"+" 4 point junction/"L" Elbow ||T| TS1 S2| ||--R1--C1--R1--||--R1--C1--R1--|| ||--R2---T---R2--| Middle of R2s and C2s are connected directly to earth.L--C2---+--C2--LEarth/GND

author: cbassett1000
author_rank: Contributor
timestamp: October 03, 2019, 07:30:56 pm
content: Bump. Anyone?
RC delay after comparator or buffer? - Page 1
Forum section: electronics / projects

author: okw
author_rank: Frequent Contributor
timestamp: June 09, 2024, 01:17:18 pm
content: I use an opamp to determine if a sensor is above or below 2.5V. It has a lot more circuitry, I just trimmed it down for what's important. The sensor senses water level in a small tank, and the water can be a little bit wavy from time to time. So I added an RC delay on the output to relax the signal a bit. It helped, but is it better to place it after the buffer? (the buffer is there so the pump and valve controls does'nt disturb the opamp hysteresis).

author: moffy
author_rank: Super Contributor
timestamp: June 09, 2024, 03:03:23 pm
content: It is kind of a '6 of one, half a dozen of another'(i.e. more or less the same) type of question, but I think I would prefer the filtering before the comparator.

author: Benta
author_rank: Super Contributor
timestamp: June 09, 2024, 04:44:04 pm
content: Drop the gates and place a leaky integrator before the comparator.

author: shapirus
author_rank: Super Contributor
timestamp: June 09, 2024, 04:59:13 pm
content: One thing to note is that the -02 gates don't have Schmitt trigger inputs, so they aren't designed for slow input signal level transitions. A -14, -17, -132, etc. gate will be a better choice.Another problem is that LM358 is an op amp and not a comparator. I'm not sure if using it as a comparator will create any issues, though, but it's not supposed to be used like this.
RC delay on clock input of flip flop - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: April 26, 2023, 03:06:22 pm
content: The following circuit is a bit of a kludge and has obvious limitations however, this particular implementation:1) has infrequent changes on the D input2) the D input signal has a minimum high duration of 10msIncreased power consumption because of the slow transition on the clock input is not relevant because D changes very infrequently (many minutes)Looking for the lowest cost solution for setup time.Any reason not to do it?

author: wasedadoc
author_rank: Super Contributor
timestamp: April 26, 2023, 03:24:48 pm
content: If you really mean a 74175 (ie not the LS version) then R12 is too large. For a standard TTL input to guarantee to consider an input as LOW it needs up to 1.6 mA pulled out of it and the voltage to not exceed 0.8 Volts. Those two conditions cannot be satisfied with that 1k resistor.

author: Jester
author_rank: Frequent Contributor
timestamp: April 26, 2023, 03:51:27 pm
content: Quote from: wasedadoc on April 26, 2023, 03:24:48 pmSorry, the actual part is SN74LVC1G175DBVRI updated the image.

author: wasedadoc
author_rank: Super Contributor
timestamp: April 26, 2023, 03:53:36 pm
content: That makes a big difference!

author: langwadt
author_rank: Super Contributor
timestamp: April 26, 2023, 04:16:39 pm
content: why do you need a delay? can't you just connect D to 3.3V and SET to the clk ?

author: Jester
author_rank: Frequent Contributor
timestamp: April 26, 2023, 04:24:59 pm
content: Quote from: langwadt on April 26, 2023, 04:16:39 pmNow why didn't I think of that?Thank you
RC Snubber Design Hint for 3 phase AC-AC PWM Chopper - Page 1
Forum section: electronics / projects

author: ow19m
author_rank: Contributor
timestamp: July 28, 2023, 04:41:37 pm
content: Hello ,Im trying to design a 3 phase Ac-Ac Pwm Chopper, I'm having difficulty designing the snubber network for the mentioned topology.Now I tried testing this circuit on bench , with my IGBT snubber values being 10Ω10W and 0.47uF Resistance and Capacitance Respectively, Highlighted in red .While my Output RC network Highlighted in Blue had values 10Ω10W and 2.2uF Resistance and Capacitance Respectively. This was strictly a hit and trial without any type of short-circuit overload protection circuitry. For trials firstly I ran my circuit on 3 100W lamps. When I ran my circuit , all the freewheeling diode network along with the IGBT's blew off. This had to happen probably because I wasn't thinking clearly and I believe I made a huge mistake of putting 2.2uF caps on the output without any kind of choke in series . How can I optimize my 2 RC networks so that it doesn't blow off at least because of the hardware ,Also For now I have no input Filter on my Circuit.I've Also given the Rated Motor Parameters below for the current Motor I was going to run my Circuit on in future.Circuit Parameters :IGBT : FGA25N120 , 25AmpSupply Voltage : 220VLine Frequency : 50HzSwitching Freq : 1KHzMotor Parameters :Rated Power : 4KwLine to Line Voltage : 380vFrequency : 50HzStator Resistance : 1.43ΩStator Leakage Inductance : 0.00523HCitation Link :https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8675728

author: jonpaul
author_rank: Super Contributor
timestamp: July 28, 2023, 07:25:30 pm
content: 1/ Check IGBT reccomended snubber placement and values. . Ask mfg and see specs and app notes.2/ Resistors should be metal oxide or WW, but flameproof for safety and safety compliance.3/ Caps should be AC rated and specific for snubber application! Some VDE X caps may be used if the VAC is within rating 250 VACRC snubbers as a single part are available4/ Design, components, proto and debug of a 4 kW power electronic requires special experience and test equipment. Do you have it?Bon ChanceJon

author: Terry Bites
author_rank: Super Contributor
timestamp: August 02, 2023, 03:35:21 pm
content: Heres the thing....

author: johansen
author_rank: Super Contributor
timestamp: August 02, 2023, 05:28:36 pm
content: 380 volts into a 10 ohm 2.2uf rc is 38 amps.The R part of the rc snubber should match the load.A diode pumped capacitor with a resistor on the capacitor is a better choice here. Start small and debug your circuit at low voltag. Its likely you blew it up because the igbts didnt turn off (lack of dead time or lack of gate drive).
RC Snubber for Phase Regulator - Page 1
Forum section: electronics / projects

author: Regius
author_rank: Newbie
timestamp: August 03, 2019, 12:32:33 pm
content: Hi, I have a phase regulator and I'm using it for regulating the rpm of a fan - centrifugal blower. The motor is shaded pole induction motor (220VAC/28W). The regulator is working fine, but if the RC Snubber (R8+C8) is disconnected, the voltage and current are getting out of phase and false triggering / turn off of the triac occurs which is leading to very fast overheating and failure of the coil of the induction motor.What type of capacitor should I use for minimizing the chance of its failure (I’m using this regulator for 8 hours a day).Or is there a way for adding additional circuit for protection if such failure occurs. I’m currently using Polypropylene capacitor rated for 250VAC/400VDC (Wima MKP 10 -https://www.wima.de/wp-content/uploads/media/e_WIMA_MKP_10.pdf). I’m not sure if a X2 rated capacitor will be suitable. For resistor I’m using 1W/Metal Film.Also… the capacitor makes buzzing noise (the buzzing noise is slightly changing, when the firing angle is changing). Is it caused by piezoelectric effect or it is something else?

author: MarkF
author_rank: Super Contributor
timestamp: August 03, 2019, 01:07:42 pm
content: https://www.allaboutcircuits.com/technical-articles/safety-capacitor-class-x-and-class-y-capacitors/

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 03, 2019, 01:23:15 pm
content: Try a larger capacitor, smaller resistor?I'd probably go with a 400VAC+ capacitor not necessarily X2 rated, because the X2 rating allows self-healing (the cap momentarily short-circuits), and after enough self-healing the value decreases dramatically. The voltage across a TRIAC can't be much over its rated voltage anyway, so there's no problem with transients. Anyway, it's probably a small difference, and not one I would expect to show up until after years of operation.And yeah, capacitors buzz, the mechanism is electrostriction. Some do it more than others. Want to say polypropylene does less than polyester?Tim

author: Regius
author_rank: Newbie
timestamp: August 04, 2019, 06:45:55 am
content: Quote from: T3sl4co1l on August 03, 2019, 01:23:15 pmThank you for the answer.I will probably use the same type of capacitor but rated for higher voltages - WIMA MKP 10: 1000VDC/600VACThere is an Application note from ST for "RC snubber circuit design for TRIACs"https://www.st.com/content/ccc/resource/technical/document/application_note/38/88/44/b8/2c/26/44/b8/CD00004096.pdf/files/CD00004096.pdf/jcr:content/translations/en.CD00004096.pdfTheir snubber calculation for a 26W pump is 10nF Cap and 620 Ohm Resistor.I haven't tried polyester or other type of capacitors.
RC Subber component values - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: July 26, 2020, 12:12:03 am
content: Hi,I am using these triacs (the smaller opto-triac driving the large triac):https://www.onsemi.com/pub/Collateral/MOC3052M-D.PDFhttps://www.st.com/content/ccc/resource/technical/document/datasheet/bc/c6/38/ee/88/59/49/0d/CD00002263.pdf/files/CD00002263.pdf/jcr:content/translations/en.CD00002263.pdfTo switch a load of 250Vac into very large capacitors (3,000 uF) and peak currents of up to 13A.The more I have been reading up about choosing snubbers values the more confusing it was getting. How do I select the following?- Resistor's value (range?) ?- Resistor's power- Capacitor's value- Capacitor's type (film etc). Does it need to be X or Y type?Many thanks
RC2014 Retrocomputer Boards I've Designed - Page 1
Forum section: electronics / projects

author: jblang
author_rank: Newbie
timestamp: December 09, 2018, 04:49:48 am
content: I've been lurking a while and I thought I would share some of the PCBs I've designed for the RC2014 retrocomputer over the past year.Started out with a breadboarded Z80 and SRAM with an AVR as the boot loader and I/O, then decided to make it into a module for the RC2014, called thez80ctrl. I've written quite an extensive monitor environment that runs on the AVR without any support from the Z80. It can load hex and binary files from SD card into the Z80's ram and run CP/M using emulated Altair disk images stored on the card. It can also bridge other SPI peripherals to the Z80, and I've also built an add on I/O expander and RTC board to go along with it. It allows breakpoints and tracing with realtime disassembly as the Z80 executes the code.After that, I got interested in turning the RC2014 into a retro game machine, so I've also designed aset of modulesthat allow the RC2014 to play unmodified ColecoVision games: TMS9918A video card, SN76589 sound card, and joystick interface board.I designed all the boards myself using KiCad. These are the first PCBs I've ever designed. I've gone through several REVs of the boards but I'm pretty happy where they're at now.

author: t1d
author_rank: Super Contributor
timestamp: December 09, 2018, 03:28:12 pm
content: This is outside of my area of interest, but I want to complement you on the really great work. Thanks for sharing.

author: rstofer
author_rank: Super Contributor
timestamp: December 09, 2018, 07:07:43 pm
content: I have a couple of the RC2014 kits including the one for CP/M. They are a lot of fun to build but I haven't found an application. I have a 50 MHz Z80 version of CP/M and it is FAST! But I still don't have an application. Maybe one day...I did build the T80 FPGA clone of the Z80 and it is currently running PacMan. I just haven't got room for the bar table that would complete the project.