hybridfree/eevblog-posts huggingface dataset:
TLP3042 Optoisolator Triac: "always" on - Page 1
Forum section: electronics / beginners

author: PerranOak
author_rank: Frequent Contributor
timestamp: October 20, 2022, 02:59:10 pm
content: I hooked-up the TL3042 "input side" (i.e. the LED) to a battery with and external LED to see what's happening. I did the same with the "output" side (i.e. the triac).When the input is connected, the output turns on - all well and good.However, when I turn-off the input, the output stays on. The output only goes off when I disconnect the output circuit. Then it all "zeroises" and I can start the experiment again.Is it supposed to stay on under these conditions?Cheers.

author: wraper
author_rank: Unknown
timestamp: October 20, 2022, 03:04:15 pm
content: Triacs cannot turn themselves off. Therefore they usually are used with AC. These devices shouldn't be used to switch on any load directly. They are only good for controlling triac gate. Datasheet of MOC3042 is much more clear about this. Also this device shouldn't be used for 230V mains voltage, for that you need a 600V part for it to be reliable.

author: PerranOak
author_rank: Frequent Contributor
timestamp: October 21, 2022, 07:41:06 am
content: Thank you. I was fiddling around to see how it worked. I’ll look up that datasheet, cheers.
TM1637 display driver - reducing sink current - Page 1
Forum section: electronics / beginners

author: redgear
author_rank: Frequent Contributor
timestamp: September 13, 2020, 10:07:40 am
content: TheTM1637sinks 50mA current. My 7 segments maximum IFis 20mA. The reverse voltage is 5v and forward voltage is 3v. Can I safely power it from the TM1637? Here is the 7 segmentdatasheet(it's in chinese)

author: greenpossum
author_rank: Frequent Contributor
timestamp: September 13, 2020, 10:31:23 am
content: Quote from: redgear on September 13, 2020, 10:07:40 amThat may be the max but that's not my experience. In practice it actually sinks about 10 mA through the segment so after multiplexing, it works out to a more reasonable 2.5 mA effective. Then there's PWM control. What I found odd working with the TM1637 is that it didn't seem to matter what the voltage drop of the LED was, even with a display that had two LEDs in series per segment, the brightness didn't seem to be affected. You will also notice there is no limiting resistor in the reference design. You will also notice there are several types of modules on sale using different colour LEDs, and hence different voltage drops, but still no current limiting resistor. I suspect the chip has a constant current sink for each segment. They don't tell you everything in those data sheets. So just go ahead and breadboard it and check that the brightness suits you.

author: redgear
author_rank: Frequent Contributor
timestamp: September 14, 2020, 10:27:17 am
content: Quote from: greenpossum on September 13, 2020, 10:31:23 amThanks.I was scared that it could damage the display. Anyways, I will try it on a breadboard.
TMC2100 SilentStepStick stepper motor driver - Page 1
Forum section: electronics / beginners

author: engineheat
author_rank: Frequent Contributor
timestamp: July 19, 2021, 05:10:02 pm
content: I'm trying to use the SilentStepStick to drive a bi-polar stepper. While I got quiet operations, I keep on frying either the board or my Arduino. This may be due to improper startup/shutdown procedure. I was told to never disconnect the motor when it's moving.Here's my setup:Arduino Uno is powered by laptop via the USB cable, 5V pin on the Arduino goes to VIO on the SilentStepStick, pin 2 and 3 on Arduino controls the DIR and STEP on the SilentStepStick. GND on Arduino is connected to the same GND row on the breadboard that is also connected to GND on the SilentStepStick along with the negative terminal of the battery pack (four 18450 batteries, around 16 V), and the positive terminal of the battery pack goes to the VM pin of the SilentStepStick.There is a large capacitor from the VM to GNDThen I got the M1A, M2A, M1B, M2B pins on the SilentStepStick connector to the stepper.Given this setup, what is the proper way to shutoff/startup the motor and the Arduino? I heard one can write HIGH to EN pin on the driver to de-energize the motor, after which it would be safe to cut power to VM or disconnect the motor. But this requires the Arduino to write HIGH to it all the time, which is a problem if I want to power off the Arduino or upload a new sketch. If EN pin is low, and while the Arduino is on and connected to the driver, the motor will be spinning. How do I shut the thing off? Write HIGH to EN pin to de-energize the motor and then power off the Arduino and/or disconnect the battery pack?Thanks
TMC2100 stepper motor driver - Page 1
Forum section: electronics / beginners

author: engineheat
author_rank: Frequent Contributor
timestamp: July 13, 2023, 05:45:09 am
content: I was able to get very quiet operation driving this motor:https://www.adafruit.com/product/4411with the TMC2100 driver in StealthChop mode. The problem is when I startup or shut it down, I sometimes fry the chip.Here is my connection:Do you see anything wrong with my connection? Should there be a capacitor between VM and GND? Should there be pull down resistors connecting the CFG1-3 pins to GND?Based on my learning so far, I was told that:VM should be much higher than the rated voltage of the motor in order to ensure quiet operation, due to the way the driver works. Something to do with "clipping" the sinusoid. I have a 9V battery shown but I think in my original trial I used a 18V source.One should not disconnect the motor from the motor pins when the motor is spinning.One should not disconnect VM when the motor is spinning. (due to back emf that'll damage IC)You need to pull EN to VIO which will disable the driver completely. Even with no STEP/DIR signal applied, the driver is still providing standby current.VIO must be high while EN is high.I wasn't using the EN pin during my trial, which is probably why I fried the chip. I just want some guidance on the proper way to start up and shut down this setup without frying the chip. Obviously, just putting a switch between the battery to the Arduino or the driver is not going to cut it.I do prefer to power the motor and the Arduino from a single power source, and use the 5V from the Arduino for VIO. But if I have to change my setup that's fine too.Thanks

author: liaifat85
author_rank: Regular Contributor
timestamp: July 13, 2023, 08:14:20 am
content: I think adafruit forum will be a better place for this question.

author: jmelson
author_rank: Super Contributor
timestamp: July 13, 2023, 02:18:42 pm
content: Yes, if this is an IC, you DEFINITELY need an external capacitor between VM and GND to prevent voltage spikes.Jon
tmm41256p-15 DRAM tester - Page 1
Forum section: electronics / beginners

author: Homer_79
author_rank: Newbie
timestamp: July 08, 2019, 10:27:03 pm
content: Here is the datasheet, for the tmm41256p-15https://4donline.ihs.com/images/VipMasterIC/IC/TOSC/TOSCS32892/TOSCS32892-1.pdfI'm doing some work with DRAM, so I thought i'd start with something simple.This is basically what I want to build, but I thought I would start by understanding how the software works first.http://www.chronworks.com/DRAM/http://www.chronworks.com/DRAM/memoryTest.inoI can follow the code through and it kind of makes sence. Its just an array of 512x512 bits.But how the decoding of the 9 bits is something im struggling with.// First write all Zeros to DRAMdigitalWrite(DIN, LOW);for(col = 0 ; col < 512 ; col++){for(row = 0 ; row < 512 ; row++){PORTB = row & 0x3f; // Write out ROW address ---- Why set all 6 bits to 1's?PORTC = ((col & 0x1c0) >> 6) | blue; ---- what does this line do?I thought portc would start off at bits 0, not the upper 6I'm just starting out with arduino, so forgive me learning curve.many thanks
TMS320F28379D and adc connection - Page 1
Forum section: electronics / beginners

author: Apollo1234
author_rank: Contributor
timestamp: July 09, 2024, 12:50:39 am
content: Hi there!I´m looking for some hilightment, implanning to use a tms320f28379d mcu in an university´s project but cant understand where the adc pin are connected. i have spent a lot of time triing to find it in the datasheet but had no luck. can someone tell me pls

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 09, 2024, 05:50:07 am
content: Quote from: Apollo1234 on July 09, 2024, 12:50:39 amI don't know how you search for things, but in thedatasheetthe pins are clearly shown in chapter 5, "Pin Configuration and Functions". There are loads of ADCIN pins to be found. According to the features there can be up to four ADC's in the chip.
TMS32F28379D - Page 1
Forum section: electronics / beginners

author: Apollo1234
author_rank: Contributor
timestamp: October 10, 2024, 03:16:43 pm
content: Hi there, im trying to control the epwm6 in the cpu2 of the refered mcu but im not beeing able to do it. In the cpu1 main i assing the gpio muxus to the correct positions ang give the onwership of the epwm6 module to the cpu2. in the cpu2 i enable the clock for the epwm6 and configure it but it dosent work. do i need to give te onwership of the gpio to cpu2 as well?

author: mtwieg
author_rank: Frequent Contributor
timestamp: October 11, 2024, 11:54:26 am
content: There shouldn't be any need to assign the GPIO to CPU2, so long as CPU1 has already configured it as required.I would first try and set up the ePWM6 with CPU1 only, to make sure your configurations are correct. Then try and replicate it using CPU2.I recall that peripheral clock control with CPU2 has some tricks to it. Look up the CLKSEM register.

author: Apollo1234
author_rank: Contributor
timestamp: October 11, 2024, 10:25:24 pm
content: Hi,Thank you! I found the problem. When passing ownership to CPU2, I completely overlooked that it’s an EALLOW-protected register. Adding the necessary lines solved my issue.Thanks again!
TO-220 MOSFET, is the tab live? - Page 1
Forum section: electronics / beginners

author: cellularmitosis
author_rank: Unknown
timestamp: June 18, 2018, 10:11:15 pm
content: Heyo, bit of a noob question:How can I tell if the tab of a TO-220 MOSFET is electrically connected to the drain, gate, source, or is disconnected?I've seen some datasheets explicitly call this out, but I couldn't find it in the IRF510 or IRF610 datasheets, for example.https://www.vishay.com/docs/91015/sihf510.pdfhttp://www.vishay.com/docs/91023/91023.pdfI suppose I can just break out a multimeter when I get home from work, but I thought I'd ask in case there is something obvious I'm overlooking in the datasheets.Thanks!

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: June 18, 2018, 10:22:22 pm
content: Hmmm, most datasheets tell you explicitly. TO-220 tabs are always connected to either pin 1,2 or 3 in my experience.So if the datasheet doesn't tell you try googling?! for irf510 pinout or similar...quickly found D is also tab.Just tested a real one, yep, it is.

author: Zero999
author_rank: Super Contributor
timestamp: June 18, 2018, 10:27:03 pm
content: The tab is normally connected to the middle pin, which is usually the drain on a MOSFET.Devices with isolated tabs do exist, but the tab is normally non-conductive and it will explicitly state it on the data sheet. If there's no mention of an isolated tab, on the data sheet, then assume the tab is connected to the drain.

author: james_s
author_rank: Super Contributor
timestamp: June 18, 2018, 10:30:53 pm
content: I don't recall ever seeing a non-isolated TO220 package where the tab wasn't connected to the middle pin.

author: wraper
author_rank: Unknown
timestamp: June 18, 2018, 10:36:38 pm
content: Only for triacs isolated tab is a common thing. As of isolated MOSFETS, they come in variant of TO-220 package in which tab is fully covered in plastic (TO-220F).Quote from: Hero999 on June 18, 2018, 10:27:03 pmYep, middle pin connected to the tab is a standard thing, and not only for MOSFETS but basically any device in TO-220 package.

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 18, 2018, 10:47:29 pm
content: I guess it's good and bad. Sometimes it makes it easy to check a voltage, but myself-included, we have no idea how dangerous and easy it is to touch something by accident.Sure hope no one finds out.

author: cellularmitosis
author_rank: Unknown
timestamp: June 18, 2018, 11:19:03 pm
content: Thanks so much guys!

author: Belrmar
author_rank: Regular Contributor
timestamp: June 18, 2018, 11:27:04 pm
content: you can always test it with a multimeter if the datasheet does not give you enough info

author: aju11
author_rank: Contributor
timestamp: June 19, 2018, 12:13:02 pm
content: Yes. and usually it is connected to the drain pin.You have to be careful while mounting it on a heat-sink.
TO Case BJT NPN Transistor Values - Page 1
Forum section: electronics / beginners

author: Robbie010
author_rank: Contributor
timestamp: February 04, 2019, 07:20:49 pm
content: Hi All,Back again for more help with my amplifier project.My component tester arrived today so I pulled one of the TO output transistors.It came back as a BJT NPN transistors with the following values:hFE = 44Ube = 676mVIc - 6.0mA536mV between Emitter & CollectorAs I am overhauling and upgrading the amplifier I will be looking to replace these with new so could somebody please tell me what these numbers mean in laymans terms and what values I should be looking for in a replacement part?Thank you!

author: Benta
author_rank: Super Contributor
timestamp: February 04, 2019, 07:49:52 pm
content: They mean nothing, except that your part is probably OK. Finding maximum collector voltage or maximum power is futile.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 04, 2019, 08:37:22 pm
content: hFE should be the current gain. The value of 44 is about normal for a power transistor.Ube should be the base to emitter voltage. The value indicates a single transistor (no Darlington). One might need to readjust the standing current if much different.Ic and the emitter to collector voltage should be just the operating point. Though only 540 mV would be rather low, but too much for saturation voltage at the usually low test current. So this does not provide much confidence in the numbers.For a replacement it is more about maximum voltage, SOA curve and maybe transit-frequency. So looking for a replacement more starts from the original part number and the circuit.

author: Robbie010
author_rank: Contributor
timestamp: February 05, 2019, 12:11:27 am
content: Thank you.Unfortunately, there are no markings at all on the body of the transistors, so I'm out of luck there......I am in the middle of trying to draw up a schematic for the amplifier so I'll see where that leads me.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: February 05, 2019, 08:08:31 am
content: I tried to copy and paste Wikipedia here but it won't let me because of a 5000 character limit.So I'll drop a link instead.https://en.wikipedia.org/wiki/Bipolar_junction_transistor
TO package capping technique - Page 1
Forum section: electronics / beginners

author: blueskull
author_rank: Unknown
timestamp: June 06, 2018, 02:04:23 am
content: I'was born in 1992, and I've never lived in the age where metal cans are commonly used to house transistors.That being said, I am interested to know how a TO package is capped.I tried to search, but I didn't find much information.To my understanding, the GTMS is only used on pin feedthrough, but not cap sealing.Soldering is an apparent option, but is there a way that I can get around with that? My design houses an MCM in a TO can, not just a single chip, and the MCM is soldered with SAC305, so I will risk reflowing the internal if I globally solder the cap.Laser soldering or welding is out my reach, so let's put that aside.Is there a low temperature GTMS process that is below 217C, or is there some other ways to seal the cap?Stud welding or epoxy sealing are appealing, but I need hermetic seals.Another way I can think of is to use Nanofoil, but to cut that thing to a continuous ring shape without a Q switched laser is a challenge.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 06, 2018, 08:44:11 pm
content: I thought those were always welded. That is, a spot welder with probably a bit more current than usual, and a hollow ring shaped electrode. I'd read that weld spatter was an early reliability problem, so it needs to be done a little more carefully than ordinary fabrication welding would do.The height of the "coin" would help block spatter. Also, TO-39s are welded, and I think they can have an emboss or coin on the base, for the same benefits?A blob of silicone goo, encapsulating the chip, would also help.This explains the popularity of steel bodies over aluminum or copper, though aluminum was fairly common too (I want to say Motorola used them a lot?). Aluminum can be spot welded, but doing it without overheating the chip would be a bit more challenging.I suppose you can't get Pb90 or the like for the MCM?As to speculation... what is this, challenging APEX at their own game? Shouldn't be hard to compete if you get even modest production quantities.Tim

author: floobydust
author_rank: Super Contributor
timestamp: June 06, 2018, 09:54:35 pm
content: The TO can is also used for high speed optical use, so GTMS would be used on the cap with the lens.It can be stamped, shelled or soldered.SCHOTT TO Headers
To study wave modulation - Page 1
Forum section: electronics / beginners

author: Jasonbit
author_rank: Regular Contributor
timestamp: September 20, 2018, 04:53:27 pm
content: Hello folks,I have this circuit:https://snag.gy/nQyk6v.jpgThrough simulate software I can see and understand the wave shape output. I connected the sinusoidal wave with 10V amplitude in Vinput and I get a new wave shape in connectors Vouput. I want do this in my lab. I have a generator function and a power supply. How should I connect all equipments to do the same thing I did in simulation software?Something that is leaving me confused it is the fact that put in serie a function generator and a power supply.Is it possible?
To tie unimportant stuff to sensitive circuit board - Page 1
Forum section: electronics / beginners

author: Noise0
author_rank: Contributor
timestamp: March 12, 2021, 10:46:13 am
content: HiI have my circuit board inside the case, it has a ground plane and I have taken all the precautions to keep the noise low and to have nice and clean voltages in the system.Then I have to tie up unimportant stuff to the main board, tipically user interface / potentiometer / led.I have the habit to put some impedence on those wire that originate from main board and goes around the case.In my primitive understanding of electronic this could act as a block to prevent irradiated noise catched by wires to enter in my system.Do it make any sense? Or this kind of precaution is useless?thx a lot

author: bob91343
author_rank: Super Contributor
timestamp: March 12, 2021, 06:37:15 pm
content: This is unclear. I don't know what you are trying to do nor what your circuit does.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 13, 2021, 01:26:17 pm
content: In noise-sensitive applications, series resistors at fast digital output pins, right at the driving source, help. Usually just some 47R is enough. In case of LED, this would double as the current-limiting resistor. Placement at the driver, not at the LED, would offer some EMI benefit but the difference would be small.

author: wizard69
author_rank: Super Contributor
timestamp: March 13, 2021, 02:34:02 pm
content: The termination resistors might help, that isn't exactly my knowledge domain. However why design in long lead wires for things like pots? If the concern is picking electrical noise shouldn't the leads be eliminated all together?This obviously require fore thought with respect mechanical design for both the board and its enclosure. Depending upon the needs of the board it might make assembly easier.

author: Noise0
author_rank: Contributor
timestamp: March 14, 2021, 11:54:25 pm
content: Quote from: bob91343 on March 12, 2021, 06:37:15 pmIt's a PSI was wondering if all those cables going to the front end could be a source of noise for my circuit.I usually insert some impedance, but it is perhaps a useless effort
to you all electrical engineers. - Page 1
Forum section: electronics / beginners

author: calexco93
author_rank: Newbie
timestamp: June 09, 2011, 10:42:49 pm
content: hello,sorry for the bother i am a senor in high school on his way to graduation. my english teacher gave my a final project which is about the career we'll be doing once in college which in my case is electrical engineering and part of it is to interview a person who is actually in that kind of field. so umm here are the questions that i would like for you to answer to help me with my project.Questions:*name*position*how long have you been in this field?*what are the positive aspect of this job?*what are the downsides/negetives of this job?*is it a growing field? what is the outlook for high school or young college graduates over the next few years?*how do you improve/develope yourself for the work that you do?*how are you evaluated (quaterly, annually, etc)?*what is the most intriguing aspect of this profession?*what is the most tedious aspect of this professon?*is this profession growing or declining ? why?*where do you see the profession in the next ten to twenty years?*is this a field that you would recommend to someone else? why?thanx for your time and your coorporation in helping me complete this project.you can contact me/email this little survey at Calexco93gmail.com

author: A-sic Enginerd
author_rank: Regular Contributor
timestamp: June 10, 2011, 12:35:04 am
content: See my reply embedded below. My answers are very specific to the nitch of the industry I work in.Quote from: calexco93 on June 09, 2011, 10:42:49 pm
TO92 package power dissipation - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: April 27, 2014, 01:59:52 pm
content: I'm design a small board and i need to regulate 5V to 3.3V, i was thinking of using the MCP1700 in the TO92 package because i don't have a lot of space. The maximum current on the 3.3V is 200 mA so the dissipation of the regulator is P = (5V - 3.3V) * 200mA = 340 mW . The datasheet says that the TO92 maximum power dissipation is 644 mW. Do you think that the TO92 is a good choice or i should choose a regulator with a TO220 package?

author: digsys
author_rank: Unknown
timestamp: April 27, 2014, 02:10:30 pm
content: It will get quite warm, but still in-spec. Make the pads larger, that helps and one "trick" I've used is to -Use a LDO version of the TO92 with a series 1N4004 diode (Input), to drop another 0.6V and share the heat.

author: Witention
author_rank: Contributor
timestamp: April 27, 2014, 02:33:02 pm
content: TO-92 isn't meant to be a high-power-dissipating package. 180°C/W isn't going to get you too far, and there often isn't exposed metal to help get power out.

author: David Hess
author_rank: Super Contributor
timestamp: April 27, 2014, 08:10:48 pm
content: I came up with 380 milliwatts maximum in a conservative design so the TO-92 MCP1700 will work fine.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 28, 2014, 06:04:44 am
content: You can always use the SOT-23 insteadWhich isn't as bad as it sounds; with a good solid copper pour on the heatsink terminal (which is... output, I think?), the thermal performance is as good or better than a TO-92, at a fraction of the height.Tim

author: Unknown
author_rank: Unknown
timestamp: April 28, 2014, 11:25:00 am
content: Thanks all for the suggestion, at the end i will use a to-220 regulator.

author: amyk
author_rank: Super Contributor
timestamp: April 28, 2014, 11:32:40 am
content: Quote from: David Hess on April 27, 2014, 08:10:48 pmDatasheet says 131.9°C/W, at 0.38W that's ~50°C rise above ambient... maximum junction temperature 125°C, so there's still a pretty good margin.
TOF-440HAG-B-TS 4 digit 14 segment display - Page 1
Forum section: electronics / beginners

author: bluepunk
author_rank: Contributor
timestamp: April 05, 2015, 09:54:03 pm
content: Hey all!I've just "found" a 4 digit segment display with 20 pins on it. I was hoping if someone knew either the location of a datasheet or could perhaps help me with hooking this up to say an arduino board or something!On the side it says:TOF-440HAG-B-TS 10 13 28 24 HI'd say its a 20 pin dip style package? I found it in an older setop box surrounded by 3 x 74hc595 and a 74hc164 close by. I think the 164 is used to read all the buttons and the 595's are used to drive the display. (3x8 outputs == 24 which would be enough)If anyone could point me in the right direction I would be very grateful!Kind Regards,Dennis Meinen

author: dannyf
author_rank: Super Contributor
timestamp: April 05, 2015, 10:40:01 pm
content: It is not that difficult to figure out the segment information - with a power source + a resistor. 14 + 4 would be the likely arrangement.

author: bluepunk
author_rank: Contributor
timestamp: April 07, 2015, 06:29:39 am
content: I did manage to figure it out! I'd figured that it'd work way different than it actually does!
toggle  and  parallel reading - Page 1
Forum section: electronics / beginners

author: arcaderix
author_rank: Newbie
timestamp: September 19, 2023, 07:46:53 pm
content: how can i program a matrix keyboard with parallel reading and toggle interrupt and i have been researching this for more than 5 days but i have absolutely no information on this practice.have you ever done it ?

author: Benta
author_rank: Super Contributor
timestamp: September 19, 2023, 08:59:05 pm
content: https://www.eevblog.com/forum/beginners/newbies-please-read-before-posting-24542/What keyboard?12 keys?16 keys?AT 102 keys?My crystal ball is being serviced right now.

author: radiolistener
author_rank: Super Contributor
timestamp: September 20, 2023, 03:30:38 am
content: Quote from: arcaderix on September 19, 2023, 07:46:53 pmwhat do you mean when saying "program a matrix keyboard"?what do you mean when saying "toggle interrupt"?Matrix keyboard is just a set of keys, it cannot be programmed, because it doesn't have CPU and memory.Interrupt is a routine which is called by hardware request, you cannot "toggle" it.

author: ledtester
author_rank: Super Contributor
timestamp: September 20, 2023, 04:02:27 am
content: Is the OP asking how to configure and process a matrix keypad so that it generates an interrupt when a key is pressed (as opposed to having to scan the keypad periodically)?If that's the case, here is a Atmel/Microchip application note on it:AVR243: Matrix Keyboard Decoderhttps://ww1.microchip.com/downloads/en/Appnotes/doc2532.pdfA less formal discussion of how to do it:https://prog.world/matrix-keyboard-and-arduino-using-interrupts/And here's a discussion of a library which can use interrupts to process a keypad:https://www.thecoderscorner.com/products/arduino-libraries/tc-menu/menu-control-using-matrix-keyboard/

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 20, 2023, 07:38:13 am
content: I understand this is matrix keypad (ex. 4x4), then turn on all the driving columns and enable interrupt on change for the row inputs.When any key is pressed the IRQ triggers, then make a scan inside the ISR, enabling only one column at a time to find out the key.

author: arcaderix
author_rank: Newbie
timestamp: September 20, 2023, 02:30:51 pm
content: hello everyone it is the first time I post the keyboard is matrix is 4x4 and is using the atmega328p on interrupts toggel and parallel reading

author: arcaderix
author_rank: Newbie
timestamp: September 20, 2023, 02:33:58 pm
content: 4x4 matrix keyboard , using atmega328p in c
Toggle relay when press power button on remote control? - Page 1
Forum section: electronics / beginners

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: January 30, 2022, 08:12:15 pm
content: I have 5V relay board like the one pictured below. It's controlled using an IR receiver and the remote control.The relay switches when I press the power button on the remote, but it resets as soon as I let go of the button. I tried programming the board as per the instructions (hold down the button on the board for 5s, release and press the button to turn on etc). But that didn't work. I want to to switch the relay on when I press the button, and then switch it off again when I press the button a second time. Does anyone familiar with this type of board know how to achieve this?https://universalsolder.b-cdn.net/wp-content/uploads/2021/01/5071_14e323fa-c0c5-464f-93ac-04c998c9b1970.jpgThanks

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: January 30, 2022, 08:39:56 pm
content: Never mind. Face palm moment - I had to remove the jumper to change into toggle mode.

author: rpiloverbd
author_rank: Regular Contributor
timestamp: February 03, 2022, 03:15:26 pm
content: Good to know that you found the solution.
tolerance with diodes? - Page 1
Forum section: electronics / beginners

author: robowaffe
author_rank: Regular Contributor
timestamp: July 25, 2023, 02:30:33 am
content: So with a 5% resistor you get 1 parts per 20 current drift-off from what u thought the resistor was going to be, is there random error through a diode as well?

author: ataradov
author_rank: Super Contributor
timestamp: July 25, 2023, 02:43:55 am
content: Yes, literally everything has tolerance.But for diodes nobody bins them like resistors, you just get a specification for minimum/maximum values of a parameter. Real parts would be randomly distributed in the specified range.

author: Terry Bites
author_rank: Super Contributor
timestamp: July 25, 2023, 06:40:15 pm
content: Have a look at a data sheet, eg 1N4148 from Vishay.They have "scattering limits" showing the spread of a few parameters.Alex is right. Usually no one selects for them, but you can get matched diodes from manufacturers, specialist RF diodes and such.Mostly its not a worry because a sensible engineer lives with some errors and/ or designs out tolerance and drift issues.
Too high proportional gain SPM motor noise - Page 1
Forum section: electronics / beginners

author: bonzer
author_rank: Regular Contributor
timestamp: January 08, 2020, 09:23:10 pm
content: Hello everyone! I had to deal recently with an SPM motor what I discovered is that for higher gains of proportional contribution even if PI regulator was theoretically stable, it had problems because it kinda locked it making a big noise. What was the reason of that do you know? Please explain it if you know, I've been surfing on the internet but didn't find much. I heard there's something like a wobble oscillation? Kp was something like 0.098 but it started happening after 0.025.
Too less solder tin on pad? Does not stick enough? IC/Mosfet resoldering - Page 1
Forum section: electronics / beginners

author: eevblogger88
author_rank: Contributor
timestamp: May 17, 2022, 04:38:31 pm
content: Hello everyone, I have removed a (supposedly broken) Mosfet and want to solder a new one on it.Its my first time.Question:Am I correct, that there is to less solder tin sticking on the pads? (The solder tin on the pads is very flat)The middle is full of tin, but on the outside not more tin does stick onto the pad, on the picture is the maximum amount I get onto it.Is it enough solder tin for the SMD IC or does I do anything wrong and there should be more?I thought it has to be a "rounded" ball on the pads, before I solder the IC onto it.https://imgur.com/a/CLCi3S4I would love to hear your thoughts!PS.:Equipment used:Amtech ASM Flux, Hakko tip ("lead free" does stand onto it, 420 Degree on solder station), mechanical leaded HX-T 100 solder tinMaybe its a problem to use leaded tin with unleaded solder tips? (I only have unleaded solder tips, since I bought everything new and iam just starting out)

author: tooki
author_rank: Super Contributor
timestamp: May 18, 2022, 01:20:51 am
content: (FYI, “tin” = Zinn (the element) and the verb “verzinnen”, and “solder” = Lötzinn and the verb “löten”. But we never say “tin” or “solder(ing) tin” to mean Lötzinn.)Anyway, I think you’re asking if that’s enough solder on the pad, and I would say that if anything, it’sfartoo much. You don’t want the component floating on a sea of molten solder. Solder is something where you want as much as needed, but as little as possible.A better way to solder something like this is to removeallthe solder from the pads, then to apply solder paste (the gray stuff that’s actually solder powder in a flux paste) and reflow with hot air. If you don’t have solder paste and want to preload the pads with solder, then you need to add separate flux.As for temperature: 420C is very high, especially for leaded. Either you’re running the iron much too hot, or your tip is too small for the job. “Lead-free” tips, by the way, are simply tips with thicker, more durable plating that can withstand the higher temperatures of lead-free soldering better. There’s no problem using them with leaded solder.
Too Much Current for an Arduino? - Page 1
Forum section: electronics / beginners

author: brooko
author_rank: Contributor
timestamp: March 27, 2024, 05:02:52 pm
content: Hello, I'm looking at creating a custom cycle light unit, which switches between 2 or 3 strips of LEDs.I'd like to control this with an Arduino, although the current for the lighting strips could be as high as 2-3amps.I'd guess that this is too much for an Arduino directly, so would probably need some kind of driver board?So I'm thinking 8.5v dc lithium power source, powering the Arduino (VIN pin) which controls the lights via a controller board.The LED board being powered directly from the power source.Does this sound right, any thoughts/recommends are hugely appreciated.I know there are boards which can do this without the need for an Arduino but I have no experience of this and wonder whether they'd handle the current.Thanks, Andy

author: radiolistener
author_rank: Super Contributor
timestamp: March 27, 2024, 05:50:29 pm
content: Quote from: brooko on March 27, 2024, 05:02:52 pmyes, you can use some mosfet or relay driver module which can get control TTL signal on the input and can switch high current/voltage load according to your needs.But be very careful if you're trying to switch devices powered from mains.

author: jmelson
author_rank: Super Contributor
timestamp: March 27, 2024, 06:24:31 pm
content: I did something similar for a lighted safety garment, I used an AT-Tiny 13A CPU in the 8-pin package (about $0.80) and one MOSFET as the power switching device. I implemented flashing and PWM dimming under control of a couple of buttons.Jon
Too much mains noise on Hantek 5202P - Page 1
Forum section: electronics / beginners

author: testtube44
author_rank: Regular Contributor
timestamp: May 14, 2019, 03:15:19 am
content: How do I get rid of the mains hum in the waveform on my oscilloscope? Filter mode does nothing and it's still too intense, I wish there was a strong enough filter on it so I could focus in on stuff I actually want to see. How can I use the filter appropriately? User manual didn't help.

author: MrAl
author_rank: Super Contributor
timestamp: May 15, 2019, 01:42:56 pm
content: Hi,I have no experience with that scope but in general this will happen when there is a bad ground connection in one of the probes.Just something to check first.
Took apart LCD screen, can't find any Pinouts online - Page 1
Forum section: electronics / beginners

author: AaronVB
author_rank: Newbie
timestamp: December 23, 2018, 02:31:01 pm
content: Hey yall,I recently took apart a BenQ G900D monitor and inside there was (like expected) a power circuit and a video circuit. Now i want to replace the power circuit inside, but the cable that connects the power to the video circuit does not have a pinout on the connector nor did i find one online. Is there a standard for the pinout or did i miss anything? Ill attach plenty of pictures for you guys. Thanks for any help!Pictures:https://drive.google.com/open?id=1-OQPWnXDNrjwwEUZ2h-hgphnffauOuxD

author: AaronVB
author_rank: Newbie
timestamp: December 23, 2018, 05:31:08 pm
content: Good News: I dont need the Pinout anymore.Bad News: One of the 4 flat cables coming from the video circuit, going to the LCD fell off.
Tool for bus sniffing and direction detection? - Page 1
Forum section: electronics / beginners

author: agehall
author_rank: Frequent Contributor
timestamp: December 01, 2015, 07:46:35 am
content: I need help figuring out what kind of tool I'm looking for - googling words like "monitor", "bus" and "driver" doesn't really give relevant results...My problem is that I have a bus that consists of three wires, CLK, SDA and SRQ. I want to sniff the traffic but I also want to detect the direction of it as either side can be driving things. I'm far from an expert, but I don't see any way of accomplishing this with a simple logic analyzer.Surely there must be a piece of ready-made hardware that can do this? I'm looking for something cheap and we are talking low speed here, way under 1Mhz.If there isn't a ready-made tool for this sort of thing, my backup plan is to cut the three lines I want to monitor and toss an Arduino inbetween so that I can detect incoming data from both ends and pass it to the other side.Any suggestions for how to do this?

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: December 01, 2015, 08:00:08 am
content: Bus Pirate is open source, so you could tweak it to fit your needs.
Tool Kit - Page 1
Forum section: electronics / beginners

author: jlcstrat
author_rank: Newbie
timestamp: April 06, 2010, 10:48:33 pm
content: I got my first job as a technician in an engineering lab. I'll need to buy a tool kit. Any recommendations? Pre-packaged or put one together?

author: MTron
author_rank: Regular Contributor
timestamp: April 06, 2010, 11:34:38 pm
content: As a moonlighting computer field tech i find the only kit i was ever (and am) happy with was the one i made myself. I found a nice messenger bag style tool bag, and i selected the tools i wanted.I found that it was much cheaper over all, and better quality then most pre-made tool kits, especially since i patiently wait until there is a big sale at a local tool store. Here in Canada, we have Canadian tire. While the tools they make are generally not the best quality, you cant really screw up basic hand tools too much, so when their better ones go on sale (some times up to 50% off!) i buy em up.As for the better quality tools, i shop around the smaller more niche tool supply outlets. Ebay is also a great source, thats where i got my Amprobe 34XR-A multimeter....really love this multimeter (save for the agonizingly slow continuity test)Dont know what your kit size/load out needs to be, but i advocate making it urselfIf your pressed for time buy a mid to low range kit and upgrade and expand as necessary, also gives u time to shop around for the tool bag/box you like.... this is the one i personally use...love it...http://kunysleather.com/products/detail002.asp?partNo=SW-1122

author: jlcstrat
author_rank: Newbie
timestamp: April 06, 2010, 11:46:01 pm
content: Thanks...That's a cool bag. I'm expecting a suggested list of tools within the next few days.
Tools for electronics and electrical installations - Page 1
Forum section: electronics / beginners

author: mike_mike
author_rank: Super Contributor
timestamp: June 16, 2018, 06:26:42 pm
content: Dear Forum,I am interested in buying some tools for my electronics and electrical workshop. I need pliers and screwdrivers (combination pliers, long nose pliers, side cutters, screwdrivers like PH1, PH2 etc.).I found on the internet some Unior tools.Have someone used them ?Are they good quality ?In my country Unior tools have very good prices, so I want to know if it is worth to buy them and if they are good quality.

author: malagas_on_fire
author_rank: Frequent Contributor
timestamp: June 16, 2018, 07:35:46 pm
content: Long time ago i have a snips from this brand and its was good, but then i forgot it somewere else and never saw it again...Now i tend to use the brand Acesa which is very good also.

author: 2N3055
author_rank: Super Contributor
timestamp: June 16, 2018, 08:45:49 pm
content: Unior makes superb tools. They don't make much electronics tools, but mechanical and electricians tools are excellent.Highly recommended.

author: mike_mike
author_rank: Super Contributor
timestamp: June 24, 2019, 08:41:21 pm
content: Did anybody tested Unior tools and can share an opinion about their tools ?
Tools for viewing the analysis of Impedance vs Frequency performance of Power Ra - Page 1
Forum section: electronics / beginners

author: Freshman
author_rank: Regular Contributor
timestamp: March 01, 2025, 05:29:18 pm
content: I noticed that there are a few online tools/plotters that are there for Power Delivery Network analysis. They show the impedance profile (Impedance vs Frequency graph) for the power rails after providing the capacitor value inputs and the stackup related information.However, I noticed that some ECAD tools like Altium designer have the power delivery network analysis (PDN Analyzer). But they don't provide us with the plots of Impedance vs Frequency of the rail with the capacitor inputs and PCB stack-up information.I searched but couldn't find a tool that can provide the impedance vs frequency plots. Any idea on what CAD tools that I could use to view these impedance profile plots?
Tools to replace relay in humidifier - Page 1
Forum section: electronics / beginners

author: egmiii
author_rank: Newbie
timestamp: January 21, 2020, 04:59:11 pm
content: My Honeywell Truesteam HM512 humidifier threw an error code this week. The troubleshooting manual states "The backup weld monitor input is active when the backup heater relay is off." There are two Tyco T9AS5D12-22 relays controlling the heating coil. My guess is that one of them welded shut. I'd like to take a stab at replacing them for $9 before tossing the unit and spending a $1000 on replacement. Clearing the service code allows the unit to run for a few hours before tripping again, so I can possibly perform some tests with a meter to verify my assumption.My question is, can someone recommend a good set of tools to complete this repair? Iron, solder type and size, etc. I already have some 0.10" Chemtronics wick to remove the old component. It's been 15 years since I last soldered and my old tools were lost in a move. Things have obviously changed a lot since then and some fresh recommendations would be helpful. The vast selection on the web is overwhelming.FYI, I've done significant work with 120/240 residential wiring, so I understand the dangers and know how to work safely.Appreciate your help.

author: ender4171
author_rank: Contributor
timestamp: February 07, 2020, 03:29:59 pm
content: Budget?Replacing a robust through hole component like those relays should be pretty easy with even a basic fixed temp 25 or 40 watt iron you could get from any hardware store. If you want something for future projects, I would get a full station or at least something like a TS100.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 07, 2020, 05:19:50 pm
content: Definitely depends on your future use. Though with a $1000 opportunity cost your budget should be large.Personally, for these high heat capacity parts I like the old school Weller soldering guns. Model numbers like 8200 or 9400. 100/140 W. $20-50 depending on whether you buy a clone and how much markup your retailer provides. The kits come with enough solder to finish this project. Just be careful not to burn the board.Other options as mentioned in the previous post are fine too. And they will be more useful for the more general electronic use you may have. If you foresee doing any SMD work you want to go for the soldering station.
Tools used for Raspberry Pi Pico development - Page 1
Forum section: electronics / beginners

author: xy
author_rank: Newbie
timestamp: May 28, 2022, 07:11:08 am
content: Hi guys,Could you recommend what tools are suitable for Raspberry Pi Pico development?Pi Pico's clock speed is 133MHz.oscilloscope/logic analyser (e.g.https://siglentna.com/digital-oscilloscopes/sds2000xp/)power supply (e.g. Siglent Technologies SPD3303X-E)multi-meteretcThank you.

author: ataradov
author_rank: Super Contributor
timestamp: May 28, 2022, 07:21:06 am
content: It depends on what you want to do. It is entirely possible to develop without any tools at all.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 28, 2022, 07:29:33 am
content: For using a kind of ready made µC board the main tools needed are SW tools. The hardware is to a large parte ready made and the outputs don't see the full clock. How much extra is needed on the hardware side depends on the extra hardware build in addition to the µC. With some care on the signal integrety one could well get away without testing the electrical side. The electrical side can be relatively easy and may not need any debugging. A DMM to measure the supply current may help if power consumption is critical.For a final commercial product one would need EMI testing. While the final test may well be external, it helps to do some preliminary tests with local instruments like a spectrum analyser with probes.

author: xy
author_rank: Newbie
timestamp: May 28, 2022, 08:56:09 am
content: Thank you.

author: eugene
author_rank: Frequent Contributor
timestamp: May 28, 2022, 12:43:20 pm
content: Quote from: xy on May 28, 2022, 07:11:08 amThe official Pico SDK:https://github.com/raspberrypi/pico-sdkMicroPython:https://www.raspberrypi.com/documentation/microcontrollers/micropython.htmlIf you use PlatformIO:https://docs.platformio.org/en/latest/boards/raspberrypi/pico.htmlYou can even program it as an Arduino:https://www.tomshardware.com/how-to/program-raspberry-pi-pico-with-arduino-ide

author: themadhippy
author_rank: Super Contributor
timestamp: May 28, 2022, 11:12:51 pm
content: Quoteor in Basichttps://geoffg.net/picomite.html

author: rstofer
author_rank: Super Contributor
timestamp: May 28, 2022, 11:18:44 pm
content: Visual Studio Code is a nice IDE and it works with the Pico when you install the proper extension. Instructions are all over Google.Thonny is another IDE that works pretty well. It doesn't have near the capability and complexity of VS Code - that might be a plus. Again, instructions are all over Google.Start here:https://www.tomshardware.com/how-to/raspberry-pi-pico-setup

author: xy
author_rank: Newbie
timestamp: May 29, 2022, 12:56:06 am
content: Thanks guys. Based on the responses, I guess the software part is the main requirement. I will use VSC and C++ for developments.