hybridfree/eevblog-posts huggingface dataset:
Complementary transistors substitutions (2SC1382 & 2SA682) - Edited - Page 1
Forum section: electronics / beginners

author: michalism
author_rank: Regular Contributor
timestamp: March 28, 2023, 01:45:41 pm
content: Hi,I'm working on an old JVC amplifier, and I want to change two pairs of the old transistors it has. The old models are 2SC1382 and 2SC682.Models BD139/ BD140 seem to be the closest replacements, but I have also seen on another forum that MJE182/ MJE253 can also be used.I checked the data sheets and with a little help from ChatCPT, I made a table with the main characteristics of each model. I've attached the file, here's also a picture (can't copy the table correctly...)I am under the impression the the MJE series is more common in audio amplifiers than the BD series. is this correct?Is there a particular reason to prefer on type from the other?Please note that the transistors I'm replacing are used to drive the final stage power transistors( 2SC1030 and 2SA757)Thank you!Michalis

author: BillyO
author_rank: Super Contributor
timestamp: March 28, 2023, 01:59:23 pm
content: As long as the current capability, operating voltage and gain are the same (or a bit better) you can certainly safely give them a try. Whether or not they end up sounding as good or not .. well, as they say the proof of the pie is in the eating.Try them.

author: MathWizard
author_rank: Super Contributor
timestamp: March 28, 2023, 10:56:45 pm
content: IDK many BJT's, but I've been using TIP31/41 (32/42) series as my main power transistors. The TIP41C is similar to one you mentioned, maybe a bit lower VCE max. They are fairly cheap, they seem fine to me. But for audio, yeah nevermind, IDK.https://www.onsemi.com/pdf/datasheet/tip41c-d.pdf2SC1030 equiv'shttps://alltransistors.com/transistor.php?transistor=11332

author: rfengg
author_rank: Regular Contributor
timestamp: March 30, 2023, 01:43:14 pm
content: Quote from: michalism on March 28, 2023, 01:45:41 pmYou have mixed up part numbers in your Excel sheet......there is no way a 2SC682 will handle 1.5A as shown in your Excel sheet and also, afaik the 2SC682 is an NPN , not a PNP as shown in your Excel sheet.

author: michalism
author_rank: Regular Contributor
timestamp: March 31, 2023, 07:46:16 am
content: A great example of human laziness and AI failure!The table I attached is created by ChatGPT, because I was too lazy to do it myself.Apparently, the data used by the AI model is not accurate, and I should have checked better.Also, another typo I made: the correct transistor type I want to swap is 2SC1382 and2SA682. Apologies for all the confusion!! I corrected the title as well...Anyway, I think I'll use BD139 & BD140 to replace 2SC1382 & 2SA682. They are the easiest to find in my area.Digging a little further on my own I found that BD790,BD792 or KSE172 can also be used instead.Is there any particular reason why I should chose a particular series over another?Thank you
Complete data sheet for APA106 diodes - Page 1
Forum section: electronics / beginners

author: agehall
author_rank: Frequent Contributor
timestamp: June 22, 2021, 06:02:39 pm
content: I’m trying to use an APA106 RGB diode and I’m having some issues. Does anyone know where to find a complete data sheet that specifies IO voltage levels? The data sheets I’ve found only specifies the timings for high and low bits.

author: Terry Bites
author_rank: Super Contributor
timestamp: June 23, 2021, 04:00:47 pm
content: It shows a Vdd of 5V on the datasheet. Vdd tells you its cmos. So about 1/3 and 2/3 vdd are most likely where your logic thresholds lie. I'd assume that that the LED Vdd and your system need to be about the same else you need a level shifter. [They eat 60mA each (R+G+B all on). 1mA all off. Allegedly] Check your rails aren't sagging or boucning during logic tranistions. Look at you local decoupling scheme. You probably need 100n right at the LED leads.

author: agehall
author_rank: Frequent Contributor
timestamp: June 23, 2021, 04:44:10 pm
content: What datasheet did you find? In the one I found at Adafruit I can’t see anything about CMOS…I’ve managed to drive one using Vdd at 5V and 3v3 on DIO but I’m guessing that is borderline… No caps on the bread board yet.

author: Smokey
author_rank: Super Contributor
timestamp: August 02, 2024, 10:43:50 pm
content: True, this does compete for worst datasheet award...https://cdn.sparkfun.com/datasheets/Components/LED/COM-12877.pdf
Complete idiot question about measuring continuity on headphone cable - Page 1
Forum section: electronics / beginners

author: Mp3
author_rank: Frequent Contributor
timestamp: August 15, 2018, 05:19:32 am
content: Hi Everybody,I got 5 sets of cheap headphones in the mail. on 2 of 5 sets the phase is backwards.I took the drivers off so i could test the wire to the 3.5mm plug with my multimeter. I set it to continuity and tried measuring to all 3 points on the 3.5mm plug, but got continuity on all points......I'm trying to figure out if the wire is wrong or the markings on the drivers are, how should i tell?

author: GadgetBoy
author_rank: Regular Contributor
timestamp: August 15, 2018, 05:25:38 am
content: You'll get continuity on all points because of the coil in the speaker. You'll need to de-solder the driver before making any continuity tests.Sent from my ONEPLUS A3000 using Tapatalk

author: homebrew
author_rank: Frequent Contributor
timestamp: August 15, 2018, 05:29:54 am
content: Quote from: Mp3 on August 15, 2018, 05:19:32 amJust use an Ohm meter and measure resistance. Your coils will have some impedance that will help to detect if it is a dead short (i.e. pont-to-point connection) or if it is measured across the coil.

author: drussell
author_rank: Super Contributor
timestamp: August 15, 2018, 05:46:06 am
content: TheTip-SleeveDC resistance should read the same as theRing-Sleeve. Measuring fromTip-Ringshould read twice the DC resistance of the previous measurements when taken with your typical multimeter.That doesn't tell you if one of them is wired backwards and thereforeout of phase, of course, but that is very easy to hear when you listen to any mono or stereo signal. If it is wrong, reverse the+/-wiring on the pair of leads to either one of the headphone capsule "speaker" drivers and it will cure your phase-reversal problem.If you want to be fully correct from a technical sense, by convention a positive voltage on a+terminal on a speaker driver relative to the-terminal should normally push outwards on the diaphragm. You won't normally hear a difference in most typical applications regardless of whether+is pushing out or-is pushing out as long asall the drivers in your system are in phase.Matching phase between disparate units is the reason for thepositive-differential-voltage-is-outwardstandard convention.Edit:This gets trickier when you start to add crossovers in speaker systems, etc. where the phase shifts you're dealing with aren't 180-degrees, but that's another topic.

author: Mp3
author_rank: Frequent Contributor
timestamp: August 15, 2018, 05:47:04 am
content: Thanks to all. I've desoldered the wire from the headphones and was able to make my measurements
Complete Newb Here. Signal to sound. - Page 1
Forum section: electronics / beginners

author: Psyrex
author_rank: Newbie
timestamp: December 19, 2021, 01:50:06 pm
content: My field is laser research, I need to be able to create a stable audio frequency.Can I do it with a signal generator and a speaker ?Or what is the cheapest way to do so ?Thanks in advance.

author: Simon
author_rank: Unknown
timestamp: December 19, 2021, 01:53:48 pm
content: That's rather vague. Yes a signal generator connected to a speaker will make a sound. You would be best to use an amplifier in between though. Given your field of research you seem to be asking something rather obvious.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: December 19, 2021, 02:06:37 pm
content: You have aVinyl playerCasette playerCD playerMP3 player ?

author: Simon
author_rank: Unknown
timestamp: December 19, 2021, 02:29:58 pm
content: question is what is the frequency and the waveform?

author: radiolistener
author_rank: Super Contributor
timestamp: December 19, 2021, 02:41:23 pm
content: Quote from: Psyrex on December 19, 2021, 01:50:06 pmIt depends on what stability level you're needs.In order to generate stable frequency you're needs to use signal generator clocked from OCXO (Oven Controlled Crystal Oscillator).If 1-2 ppm is acceptable stability level for your needs, you can use TCXO (Temperature Compensated Crystal Oscillator), it has lower power consumption, more cheap and goes into working mode much faster than OCXO, but TCXO has higher phase noise than OCXO.So, your choice will depends on your requirements.

author: Terry Bites
author_rank: Super Contributor
timestamp: December 19, 2021, 04:17:17 pm
content: I'm guessing you want a fixed pitch.Do you need a pure tone? ie no harmonics.Do you want constant amplitude?I'd buy a cheap generator that has some precision eg FG-100 DDS Function Signal Generator Frequency Counter 1Hz - 500KHz from Aliexpress.Or use your computer with some freewarehttps://listoffreeware.com/best-free-signal-generator-software-windows/https://play.google.com/store/apps/details?id=com.keuwl.functiongenerator&hl=en_GB&gl=UShttps://apps.apple.com/us/app/audio-function-generator/id768229610
Complete noob to electronics needs some helpful advice - Page 1
Forum section: electronics / beginners

author: TheRenegade
author_rank: Newbie
timestamp: January 24, 2019, 10:53:01 pm
content: Hello all,This is my first post on this website. I've searched the forums but couldn't find anything related to what I am after.To cut a long story short, I need to find out what power (3v, 5v or 12v) goes into which connector on this thing. You can see the PCI-E like connector at the top of the PCB. It's from a HP DL380 Gen9 Server. I don't have the server so I can't 'plug it into a server and find out'This is the power cable that is used is thishttps://hpecas.com/cabos-para-servidores/hp-power-cable-kit-includes-two-cables-747560-001-747561-001-784622-001_34496.htmlI have a multimeter (Amprobe DM9C) which I got at a car boot sale. I don't really know how to use it though.Does anyone know how I can find out what I need?Thanks in advance

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: January 26, 2019, 12:09:24 am
content: Quote from: TheRenegade on January 24, 2019, 10:53:01 pmIt’ll be 12 V see PCIE 6 pin powerhttp://nerdralph.blogspot.com/2016/03/hacking-gpu-pcie-power-connections.html?m=1Flip over the PCB to see which pins are gnd or measure them with low ohms.You may or may not have a “ sense” pinSent from my iPhone using Tapatalk

author: MavMitchell
author_rank: Contributor
timestamp: January 26, 2019, 07:06:32 am
content: This may not be standard pci-e. Will check on a server I have on the bench.Update: Sorry only have Gen8 at the moment. Its diferent..

author: TheRenegade
author_rank: Newbie
timestamp: January 26, 2019, 11:07:10 am
content: Thanks guys for getting back to me. it's not really a PCI-E connector, it just looks so flaming similar.That being said, the part that goes to the system board is just a flat connector with 5 pins. I just wish there was someone who had a Gen9 server
Complete Noob - Need Help - Page 1
Forum section: electronics / beginners

author: Joeavg
author_rank: Newbie
timestamp: May 30, 2019, 08:26:05 am
content: While fixing my dualshock 4, there was a metal part I had to bend to get to something I needed to clean. Out of 4 of these, one gave me trouble both getting it out and back into place. I ended up snapping this piece after repeatedly trying. I'm wondering if I can just solder this back together somehow? I've never soldered anything... Also, after this situation, my controller won't turn on. Could it be from this broken connection, or have I unknowingly destroyed something else?

author: Shock
author_rank: Super Contributor
timestamp: May 30, 2019, 10:38:05 am
content: Likely needed for the controller to even partially work, looks like it controls the x-axis on that side. It has some meat still left on it to solder makeshift pins on, but it might be a tricky job for a beginner.There are Chinese replacement parts on Ebay cheap "dual shock 4 analog stick". Not sure how reliable these are but if you can find someone to solder one in it could be a cheap fix. Either that or good time to learn how to solder.

author: Joeavg
author_rank: Newbie
timestamp: May 30, 2019, 10:53:56 am
content: I should probably take your advice and get a new replacement. A part was worn down connected to the same piece that I raised with tape to make it work again, don't know how long that will last. Thank you for your reply.

author: Joeavg
author_rank: Newbie
timestamp: May 31, 2019, 11:03:55 am
content: Can wire glue restore this connection? I haven't gotten around to fixing it yet and found out about this stuff but don't know that much about electronics repair.

author: Shock
author_rank: Super Contributor
timestamp: May 31, 2019, 11:29:00 am
content: Doubt it will be as reliable, also there might be some force on that connection. Try if you like, but I would never do that if it was mine.Considering the part is a buck on Ebay it won't hurt to order a couple. I'd look for a replacement and solder it in. If you go around to your local maker space you can probably find someone who solders to help out, or anyone who teaches or does electronics. Might be able to find a mobile phone repairer who will do it cheap, guitar repairers, audio stores that make cables, some computer repair stores. Make sure you agree on a price before getting someone to look at it.

author: Joeavg
author_rank: Newbie
timestamp: May 31, 2019, 12:26:03 pm
content: Ok, thanks again.
Complicated Power Supply Help Needed - Page 1
Forum section: electronics / beginners

author: itsme1414
author_rank: Newbie
timestamp: May 19, 2019, 04:36:03 pm
content: I am looking for a way to use the duty cycle on my function generator to make 2 different on and off times/pulses. Example would be 1 second on .5 seconds off and repeat. Have that running into some amp that can deliver 15 amps to a coil to make different on and off times/pulses to generate an on/off magnetic field in a coil/solenoid. Only way I have been able to do this is by hand so far and it is by no means accurate on the on/off pulse times. I made a nail board like people use when firing fireworks and I attached this to 2 separate coils with the nail board being powered by a 12 volt car battery. Basically shorting the car battery every time I fire using the nail board and just touching the power wire to each positive screw "connected to each coil" in the nail board back and forth but there is no way to get accurate timing. Hope this helps make sense of what I am doing but need something automated to achieve this. Thought about using capacitor discharges to do this but no way to accurately time the on/off and repeat pulses. If I could do this with just one coil that would be fine for now.What I have found so far:Could I input the function generator into this amp:https://www.ebay.com/itm/293093578653?ul_noapp=trueThen power the coils from the output? Would that amp see the coil as a dead short and not work? If so what could I put between the amp output and coil to make this work? Would a solid state switch work somehow in this setup?Thanks for any help. I know what I want to do, I just need some help to build something to power it.

author: bob91343
author_rank: Super Contributor
timestamp: May 19, 2019, 05:11:15 pm
content: It's not clear what you want to do but if you generate a rectangular wave with the on/off cycle you want, you can use it to trigger a gate that controls a solenoid. Or two gates of opposite polarity to cause one or the other solenoid driver to activate.Simpler would be to drive a PNP and an NPN power transistor, each driving its solenoid. Your only concern is adequate drive as well as suppression of inductive spike on turn off (diode).The PNP will activate when its base is pulled down, and the NPN when its base is pulled up. If you want to drive a solenoid with a higher voltage you will need another transistor in each drive circuit.If you only want to drive one solenoid you can omit either of the power transistors.

author: itsme1414
author_rank: Newbie
timestamp: May 19, 2019, 07:52:03 pm
content: Thank you for the reply. I checked on the amp in that link and what I thought were inputs on the front for a function generator look like outputs.
Component (diode?) identification help - Page 1
Forum section: electronics / beginners

author: olewales
author_rank: Regular Contributor
timestamp: April 11, 2015, 03:00:29 pm
content: Hello,I am struggling to find any information about component in the picture attached to this post. I cannot even find a matching SMD package. Looks a bit like a SOD package but none of the types I found is big enough (about 5x6mm). I am guessing this is some kind of a protection diode because of the marking on the PCB and because it is located right next to power connector across main power rail (48V). It went short-circuit after PSU failed and possibly supplied mains voltage to the rest of the circuit (shorted PCB tracks across the chassis). I am investigating if rest of the circuitry survived but I don't have access to another 48V supply yet so I am checking obvious things I can measure for now.

author: madires
author_rank: Super Contributor
timestamp: April 11, 2015, 03:49:21 pm
content: Seems to be a 3A 60V schottky diode (http://pdf.datasheetcatalog.com/datasheet/dccomponents/SK38.pdf).

author: olewales
author_rank: Regular Contributor
timestamp: April 11, 2015, 05:14:05 pm
content: Thank you both. This is it.Its embarrassing because I was now able to find datasheet almost instantlyI could swear I tried identical search query before I wrote this post and nothing showed up.Anyway, thank you once again for help.

author: olewales
author_rank: Regular Contributor
timestamp: April 15, 2015, 01:12:02 pm
content: I am happy to report that the diode has done its job and protected the rest of the logic board. Furthermore, it turns out that it could be my first tests that blew itI did not notice that interconnect cable between original PSU and logic board in my unit had reversed colors indicating polarity - red was ground and black was positive +48V. I relied on that color coding during testing, "of course"Anyway, I want to replace that diode, but original part is pretty much impossible to get where I live. Can I use any schottky diode with similar parameters or should I look for something in particular to ensure that it will do its job equally well?EDIT: Just as before I found that component locally almost instantly after sending this postBut still, I'd be interested to know if this component is in any way special in its specs.

author: madires
author_rank: Super Contributor
timestamp: April 15, 2015, 02:05:26 pm
content: Quote from: olewales on April 15, 2015, 01:12:02 pmCould be -48V telecom's DC wiring. That always puzzles engineers/technicians who aren't aware of itQuote from: olewales on April 15, 2015, 01:12:02 pmActually, the spare one just needs to have the same max. reverse voltage (when used to limit the voltage) and at least the same current. Or you could use a unidirectional TVS, or a diode and a bidirectional TVS in parallel.
component adding problem in Eagle - Page 1
Forum section: electronics / beginners

author: Savetheday
author_rank: Regular Contributor
timestamp: November 10, 2015, 02:19:06 am
content: Hi everbodyI am trying to configure a new pcb schematic in Eagle 7.4 light but some components have 3 parts (showing underneath) I could able to add first 2. parts but 3. part with P 8 16 pins wouldn't add.How do we add that?Thanks.

author: liquibyte
author_rank: Frequent Contributor
timestamp: November 10, 2015, 02:50:42 am
content: Invoke on the context menu.

author: tron9000
author_rank: Frequent Contributor
timestamp: November 10, 2015, 09:04:09 am
content: Press the Invoke button in the command bar on the left then click on the component. This will bring up the devices that still need to be placed in that package. Click on the PWR and place the pins where-ever.
Component checking in circuit - Page 1
Forum section: electronics / beginners

author: Crambone
author_rank: Frequent Contributor
timestamp: December 18, 2019, 11:39:46 pm
content: If I have 2ea identical surface mount boards and one is bad can I compare component (resister, capacitor.....) to the known good one to identify a bad part?Example: I check C1 on good board and get 10uf and then check in bad circuit and get 10uf then I can assume that cap is good? Can I keep doing this part for part until I find one that is different and then assume that is the bad part or one of the bad parts?

author: GerryR
author_rank: Frequent Contributor
timestamp: December 19, 2019, 12:23:38 am
content: I would think that taking measurements, while each unit was powered up, and comparing the voltages would give more accurate results (unless smoke has been released!).But doing it with no power is a good start. If you have a way to inject a signal and chase it around, that would be another approach. Not knowing the circuit makes it difficult to know the best approach.

author: Crambone
author_rank: Frequent Contributor
timestamp: December 19, 2019, 11:21:46 pm
content: It’s an RCI 2995DX circuit ,http://www.cbtricks.com/radios/rci/rci_2995dx/graphics/rci_2995_dx_sch.pdfTP7 was grounded by accident with the mirror board out that normally connects TP7, 8 & 9.

author: GerryR
author_rank: Frequent Contributor
timestamp: December 20, 2019, 01:17:18 pm
content: Looking at the schematic, you can check for continuity (Ohms) between Q60 collector and TP7 and continuity between TP7 and C219-C220-L26 junction, and compare the ohms readings to the good board. My first inclination is to suspect L26, but...
Component Decade Box and Component Kits - Page 1
Forum section: electronics / beginners

author: jonwilhelmjr
author_rank: Regular Contributor
timestamp: January 15, 2021, 12:34:22 am
content: I have a few goals in mind. One I would like to experiment with filters on a breadboard. I would like to have a datasheet and spice model for every component. I am willing to swap components as needed.The plan is to create a signal, calculate the outcome, simulate the outcome, and finally breadboard the outcome.The second part, I would like to build decade boxes similar toIET Resistor Decade boxBut I would like to1. have the experience of building some (it can be rewarding)2. have datasheets to reference and use spice models3. see if i could build one for cheaperThe decade boxes can use SMD, i am comfortable.I am asking for part numbers or part families. what components would be worthy of calibration. Most of all I am looking to fill my component drawers with <1% standard values for bread boarding.To summarize, What (RLC) part numbers or part families would you buy to one put in your component drawers and two what part numbers or part families would you buy to build decade boxes (RLC).

author: ledtester
author_rank: Super Contributor
timestamp: January 15, 2021, 01:38:40 am
content: For the decade resistor box you might take a look at this thread from 2011:https://www.eevblog.com/forum/projects/diy-cheap-resistor-decade-substitution-box/There's also a thread in the forums about a thumbwheel capacitance box project.But, I doubt you'll be able to make one cheaper than one that just uses jumpers instead of thumbwheels:https://www.aliexpress.com/item/4000073139731.htmlhttps://www.ebay.com/itm/8-Decade-Resistor-Board-1R-9999999R-Programmable-0-1R-1-2-SMD-Resistance-Module/402628561886QuoteI don't see the point. High-precision parts are very expensive. Besides, when you breadboard you will introducing a lot of other additional R, L and C into your circuit which will swamp the extra precision.It's better to get a good multimeter so you can measure the values of the components you have. 1% or even 5% parts should suffice for almost everything you want to do.
transistor equivalent  - Page 1
Forum section: electronics / beginners

author: yalect
author_rank: Regular Contributor
timestamp: July 21, 2017, 08:24:25 pm
content: Hi,if you help me to find equivalents of transistor BSS 110 which are availableThank you

author: Zero999
author_rank: Super Contributor
timestamp: July 21, 2017, 10:11:51 pm
content: Try the TP0610L, VP0610L or BS250. The latter has a slightly higher on resistance than the BSS110 but it might be OK.What's the application? Do you have a schematic?http://www.vishay.com/docs/70209/70209.pdf

author: bson
author_rank: Unknown
timestamp: July 22, 2017, 12:11:25 am
content: You won't find one with Rdson=10ohm, so have to choose 8 or 12; I'd go with the slightly lower. If it's for a linear application like an amplifier or regulator of some sort go with the 8 so it stays in the ohmic region and doesn't saturate. If it's not in a feedback loop and depends on the particular slope of the BSS110 you're probably out of luck, but in a feedback loop no problem. If it's for switching purposes I'd also go with 8. If you need exactly 10 for some reason you can always replace the drain leg with a 2ohm 1/8W resistor.VP2106 (12ohm, 250mA) on Mouser @ $.58; pin order is reverse of BSS110 so needs to be flippedIf you don't mind using a SOT-23 adapter, then you can find the BSS84 in SMD. (In fact, I just received 100 today from Mouser.) Perfect little jellybean P-ch MOSFET - I'll be using it to switch a power rail to 5 I2C devices including a display, so I can do a complete bus reset or power off during deep sleep. (The BSS84 may not work though; I just looked at the BSS84/BSS110 datasheet and it has a much lower Vgs which might cause problems.)
Component Id - Page 1
Forum section: electronics / beginners

author: anvoice
author_rank: Frequent Contributor
timestamp: September 29, 2018, 08:41:53 pm
content: Hello, a friend asked me for help with replacing a bad component on a device. The photo is attached. To me it looks like an inrush-limiting thermistor, with what appears to be a 150V rating. If this is for a power supply (as hinted at by the isolation slot in the PCB), this is slightly strange because they live in a region with 220V. That could explain why it broke in the first place, assuming I am correct.Is this indeed a thermistor? I can't read the current rating if it has one, so I was going to ask for a better picture, but should I tell them to replace it with one rated for over 220V?Thanks in advance.

author: Benta
author_rank: Super Contributor
timestamp: September 29, 2018, 08:45:48 pm
content: Varistor.

author: anvoice
author_rank: Frequent Contributor
timestamp: September 29, 2018, 11:42:27 pm
content: Right, thank you, the proper tern is varistor, or MOV.I got a little more information: seems like they destroyed the varistor by plugging their device, whatever it is, into 220V when it's rated for less. Apparently they now have a 220V to 110V converter and the device is working at the moment (I'm guessing they bridged the broken varistor though I don't know for sure). I see something that looks like "A8" and "c700" on the component, but a google of these doesn't lead to a compatible varistor. For selecting a replacement, should I choose one with an equal or higher rating? Is there a way to tell what current the replacement should be rated for, or should I just go on the high side (e.g. 50A) to be safe?

author: Gyro
author_rank: Super Contributor
timestamp: September 30, 2018, 10:28:47 am
content: QuoteActually, both. MOV stands for Metal Oxide Varistor.

author: anvoice
author_rank: Frequent Contributor
timestamp: September 30, 2018, 07:00:56 pm
content: Quote from: Gyro on September 30, 2018, 10:28:47 amThat much I knew.So is it safe to substitute a higher rated one, or should I use the exact voltage and current rating in the replacement?

author: drussell
author_rank: Super Contributor
timestamp: September 30, 2018, 07:36:02 pm
content: Quote from: anvoice on September 30, 2018, 07:00:56 pmUse the incorrect voltage for a MOV defeats the purpose of having it there in the first place. it isn't like a capacitor where you can go up in voltage. Going up in voltage means the MOV isn't going to clamp at the point it is supposed to. Using too low of a voltage will mean it conducts when it shouldn't and will burn or blow up.On the other hand, using a "beefier" one rated for more joules of energy dissipation (with the correct voltage for the application) is fine and would normally be desirable if physical constraints allow. MOV lifetime is somewhat related to the total number of joules dissipated over the lifetime of the device.
Component ID - Page 1
Forum section: electronics / beginners

author: PetaVolt
author_rank: Contributor
timestamp: July 04, 2021, 02:27:19 pm
content: Hey guys,I’m trying to figure out what components these are. There are two of these parts in parallel, the parallel network is in series with the input power just prior to what appears to be the main motor driver IC. All of this taking place in a variable speed pool pump controller. Unfortunately the motor driver IC has no part number or it’s on the underside of the part.My gut instinct is it’s an inrush limiter of some sort as it’s in series with the power source. I suppose it could even be a fuse.I sure wish I had a schematic.Thanks!Spencer
Component ID - Page 1
Forum section: electronics / beginners

author: arnesr
author_rank: Newbie
timestamp: October 06, 2021, 02:19:54 pm
content: I need some help in identifying this component circled in red. The only markings are a "dot 153" on the top. It is surface mounted with 8 pins.Thanks,arnesr

author: Jwillis
author_rank: Super Contributor
timestamp: October 06, 2021, 02:52:53 pm
content: Line filter for EMI supression . Shielded but could be common mode or differential mode

author: arnesr
author_rank: Newbie
timestamp: October 06, 2021, 03:21:18 pm
content: Thanks for such a quick reply. I don't know if I will be able to source a replacement. I seem to have buggered this one while prying the case off to get to the board to attempt to fix another issue. The case(fish finder) was glued together, not designed to be serviceable.

author: Jwillis
author_rank: Super Contributor
timestamp: October 06, 2021, 11:51:39 pm
content: Quote from: arnesr on October 06, 2021, 03:21:18 pm153 denotes 15mH Digikey seems out of stock but it might give you what your looking for.https://www.digikey.com/en/products/filter/fixed-inductors/71?s=N4IgjCBcpgbFoDGUBmBDANgZwKYBoQB7KAbRACYBOAFkoAY6QBdAgBwBcoQBldgJwCWAOwDmIAL4EAHI2ghkkdNnxFSIanXJ0AzBBYgOXXoNETx4oA

author: arnesr
author_rank: Newbie
timestamp: October 07, 2021, 01:16:55 am
content: Excellent work, thanks so much finding the part for me. I had searched through several pages to no avail, not knowing what I was looking for.It looks like Mouser has them in stock.https://www.mouser.com/ProductDetail/652-SRR0908-153YLI may order a couple and see if I can get the unit back in operation.
Component I/D please. - Page 1
Forum section: electronics / beginners

author: midsomerdave
author_rank: Newbie
timestamp: January 18, 2025, 09:33:45 pm
content: Hi everyone. Can anyone help me and identify the components in the picture? Many thanks if you can. Regs, Dave.

author: Gyro
author_rank: Super Contributor
timestamp: January 18, 2025, 09:38:35 pm
content: They're high frequency signal (tuneable) transformers. Probably from the IF strip of a radio. You can see the capacitor in the base of one of them.

author: midsomerdave
author_rank: Newbie
timestamp: January 18, 2025, 09:41:03 pm
content: Many thanks Gyro...yes, they came out of an old Aiwa combo unit. Cheers.
Component identification - Page 1
Forum section: electronics / beginners

author: lthrelfall
author_rank: Newbie
timestamp: December 23, 2018, 02:46:39 pm
content: Hello,Can anyone tell me what this damaged component is in the attached photo, its on the logic board of a iMac 14,2?I can't see any part number on it, but expect its the same as the undamaged one on the left, the connector below goes to the left hand speaker.Any help is appreciated.lthrelfall

author: wraper
author_rank: Unknown
timestamp: December 23, 2018, 02:58:43 pm
content: Common mode choke.

author: David Hess
author_rank: Super Contributor
timestamp: December 25, 2018, 01:27:03 am
content: A agree; it looks like a common mode choke to protect against RFI which is a real problem with audio amplifier outputs.

author: lthrelfall
author_rank: Newbie
timestamp: December 26, 2018, 08:32:34 pm
content: Thanks for the replys,Is it normal for there to be no id number on them? do you think its worth unsoldering the good one to see if theres any code on the underside?Best,lthrelfall

author: wraper
author_rank: Unknown
timestamp: December 26, 2018, 08:40:29 pm
content: Absence of marking is pretty normal. You could measure inductance and find a similar part. Replacing it with 2 separate ferrite beads would work too. Even using 2 jumpers would work, although there would be more RF emissions from the laptop.
component identification - Page 1
Forum section: electronics / beginners

author: J4e8a16n
author_rank: Regular Contributor
timestamp: May 24, 2013, 12:45:00 pm
content: Hi,Here is a computer power supply mpxgmf 08g ( the yellow piece). It is wired to the 100ac input. What is the use of it ? How do you name this?Regards,JPierre

author: madires
author_rank: Super Contributor
timestamp: May 24, 2013, 12:54:00 pm
content: Looks like a capacitor to filter HF (switching) noise.

author: Psi
author_rank: Super Contributor
timestamp: May 24, 2013, 01:25:51 pm
content: Its a mains filter cap.

author: J4e8a16n
author_rank: Regular Contributor
timestamp: May 25, 2013, 11:46:51 pm
content: Thank you very musch)
Component Identification - Page 1
Forum section: electronics / beginners

author: mikec
author_rank: Contributor
timestamp: September 18, 2013, 11:53:07 pm
content: Hi,The picture shows what appears to me to be a capacitor. The values I have read from it are 2200u, 6V3V 021K0. I can't find anything on this, but I suspect it is a tantulum capacitor, not sure at the moment what it is been used for on this board. There are 2 of these on the board along with another disc type which I believe to be a ELDC capacitor for RTC backup. Now if this ELDC is taking care of the RTC, than I have no idea why 2x2200u are required on the board.When I power of the board both these capacitors discharge to <.5V in less than 5minutes.Is it typical for capacitors like this to be used to allow micro-controller to shut down the system in a safe manner during brown-outs?Appreciate any suggestion!!MKC

author: Bertho
author_rank: Regular Contributor
timestamp: September 19, 2013, 12:00:31 am
content: The blue blob is an aluminium capacitor.The type and value 2200uF/6.3V is typical for use in a (linear) power supply and placed after the bridge-rectifier. The discharge depends on the actual load on the system and your measurement is not unusual.Large capacitors can be used to hold power long enough for proper shutdown, but that depends on the rest of the design and the firmware, You have not provided enough information to even guess (need a schematic and probably the firmware).

author: Astroplio
author_rank: Regular Contributor
timestamp: September 19, 2013, 12:04:51 am
content: Hi Mike,there is actually a long dedicated thread for this kind of stuff here:https://www.eevblog.com/forum/chat/what's-this-please-(component-advice)/I am fairly certain it is an electrolytic capacitor. From 6V3V, I understand that it is rated for 6.3V, and the large capacitance 2200uF suggests it is a bulk capacitor for the low power control circuit of your board.George

author: SeanB
author_rank: Super Contributor
timestamp: September 19, 2013, 05:57:28 pm
content: Made most likely by Siemens, they do a large number of axial aluminium electrolytic capacitors, and that size is about right for the value and voltage.Nice to see it is glued to the board as they are pretty heavy for the lead size and vibration tends to snap one lead off with time right at the case join.

author: Tube_Dude
author_rank: Regular Contributor
timestamp: September 19, 2013, 11:25:35 pm
content: Quote from: SeanB on September 19, 2013, 05:57:28 pmIt looks to me the Philips Blue axial aluminium electrolytic...

author: mikec
author_rank: Contributor
timestamp: September 22, 2013, 09:54:30 pm
content: Thanks Guys,This capacitor is placed after the regulators, not sure which yet one as there is a +12, -12 and 2x +5 regulators. I thought it just looked a bit odd with the double indented rings on the case and also I don't see alot of axial capacitors.Also it seems that Philips capacitors are branded now by Vishay.Cheers!
Component identification - Page 1
Forum section: electronics / beginners

author: bitman
author_rank: Unknown
timestamp: April 06, 2020, 01:12:10 am
content: Hey there ...Staying at home all days means you can start digging into the "junk bins" you've promised yourself for the last many years you would get to, some time.I have the following two components I got out of something - I had initially marked them as resistors, but that's obviously wrong. I need a bit of help identifying what they are - it almost looks like some kind of fuse, but I'm not sure.

author: wraper
author_rank: Unknown
timestamp: April 06, 2020, 01:15:54 am
content: Check if they measure like diodes, if not should be GDT.

author: bitman
author_rank: Unknown
timestamp: April 06, 2020, 01:43:32 am
content: Quote from: wraper on April 06, 2020, 01:15:54 amNo conductivity at all. Not when measured as a resistor or as a diode. So GDT sounds like a good guess. A quick search doesn't seem to find anything that talks about the color bands although no model number is printed on them.

author: ArthurDent
author_rank: Super Contributor
timestamp: April 06, 2020, 02:13:14 am
content: Here's a couple of GDT that also have 2 color bands for identification and look the same inside.

author: transistor12
author_rank: Contributor
timestamp: April 07, 2020, 04:07:08 pm
content: Gas Discharge Tube
component identification - Page 1
Forum section: electronics / beginners

author: glinjik
author_rank: Regular Contributor
timestamp: January 24, 2021, 08:24:18 pm
content: hi all out of interest ive got a blown led panelq1 what is the round component ? Thermistor?q2 what value should those wire bound resistors be going to the ridge rectifier?q3 what is the point of those resistors / thermistors?

author: WattsThat
author_rank: Frequent Contributor
timestamp: January 24, 2021, 08:51:03 pm
content: Resistors of some type, fusible if there is no external fuse. The other round components above and below the resistors are likely capacitors.Values are depend upon led current and other design considerations which are unknown.

author: Jwillis
author_rank: Super Contributor
timestamp: January 24, 2021, 10:59:38 pm
content: Bare disc MOV and MELF resistors .

author: fabiodl
author_rank: Frequent Contributor
timestamp: January 24, 2021, 11:43:58 pm
content: While the resistors blew, the cause is probably somewhere else. Even if you replaced the resistors, you would probably blow them again. Or did you accidentally short something?

author: Jwillis
author_rank: Super Contributor
timestamp: January 25, 2021, 02:53:19 am
content: Surge protection circuit . Causes of surges can include lightning strikes ; Power outages or blackouts ( specifically when the power comes back on ) ; High power electrical devices turning off and on like refrigerators , Air conditioners and large motors ; electrical shorts or faulty wiring ; over loading a single circuit can cause surging into other devices on that same circuit .

author: glinjik
author_rank: Regular Contributor
timestamp: January 25, 2021, 03:21:19 pm
content: hi thank you for your reply the light was on top of a pile driver machine and was exposed to the elements i noticed some condensation inside the glass before i gently opened the case with a hammeri think it was probably water ingress that caused a short just for experimentation i bridged the resistors and all works but its useless as a LED panel unless in side somewhere
Component identification - Page 1
Forum section: electronics / beginners

author: adripol
author_rank: Newbie
timestamp: March 19, 2021, 09:00:30 pm
content: Hi to all.I don't have board schematics and i'm not skilled in circuits, just basic testing/soldering/desoldering jobs.New learnerI just replaced the power button on a garmin alpha 100 handheld device and i blew of a component.Since there is no ground point beneath i'm thinking it was a resistor.Can i get some tips from you about the component... if this is really a resistor and what values could it be, what is his role near the power button.Thanks.

author: RayRay
author_rank: Frequent Contributor
timestamp: March 19, 2021, 09:17:35 pm
content: Have you tried to actually find that component? Because without it (or another, identical device, to check the PCB) it'd be impossible to determine exactly what it was! I was unable to find any service manual/schematics for this one.
Component Identification - Page 1
Forum section: electronics / beginners

author: kelemvor
author_rank: Regular Contributor
timestamp: May 30, 2021, 08:29:36 pm
content: Anyone know any tricks for identifying components? I occasionally find myself frustrated when doing so. Today I was unable to find a 5 pin chip on the PCB for my old Logitech C920 webcam. It's labeled MBFBM.Frequently I use google or sites like octopart.com but I've had no luck finding this guy.https://www.eevblog.com/forum/Smileys/default/bangheadonwall.gif

author: amyk
author_rank: Super Contributor
timestamp: May 31, 2021, 01:44:10 am
content: SWLD2340-3V6M5TR
Component Identification - Page 1
Forum section: electronics / beginners

author: Norman Later
author_rank: Newbie
timestamp: August 19, 2021, 02:56:39 am
content: Hi , am having a hard time trying to Identify the attached component it's off a video control board M.NT68676.2marking appears to be 6n08or B ,Any help would be appreciated .Norm.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 19, 2021, 06:08:30 pm
content: Good Morning Norman, That first digit you see as a 6 appears to be a G to me. But Google doesn't recognize that either.Looks like new boards are available, though. Good luck.

author: Nusa
author_rank: Super Contributor
timestamp: August 19, 2021, 06:43:43 pm
content: I don't see anything that could be that component on that board. Care to point it out for us?

author: amyk
author_rank: Super Contributor
timestamp: August 19, 2021, 11:44:19 pm
content: RP152N013C

author: Norman Later
author_rank: Newbie
timestamp: August 20, 2021, 07:58:33 am
content: Thanks I would like to know how you figured it out if possible .Norman.

author: Norman Later
author_rank: Newbie
timestamp: August 20, 2021, 08:03:04 am
content: it's the IC near the 4r7 choke it has an 8 pin Ic on the picture supplied on my board it's a 6pin ic as in the photo

author: Norman Later
author_rank: Newbie
timestamp: August 21, 2021, 12:53:19 am
content: replace old photo with correct board and marked component with arrow thanks

author: amyk
author_rank: Super Contributor
timestamp: August 21, 2021, 06:08:21 am
content: Quote from: Norman Later on August 20, 2021, 07:58:33 amClick the link...
Component identification -. 3 digit number with line over the top?  - Page 1
Forum section: electronics / beginners

author: Andrew2007
author_rank: Newbie
timestamp: May 15, 2019, 07:36:05 pm
content: HelloI've managed to cut through the cable of one of my CCTV camera's whilst trimming the ivy! 😩😲😠There's a smd component on the main board that is broken on the end, at first I thought it was a resistor but I don't know what the significance is of the line on top of the three digit number, I've taken a photo of another one on the same board. Length 3.2mm, width 2.5mm and the height is about 2.5mm which is significantly more than a smd resistor.Any idea, thanks? 🙂

author: ataradov
author_rank: Super Contributor
timestamp: May 15, 2019, 08:13:14 pm
content: What does the silk screen say?It looks like an inductor with 47 uH inductance.

author: Andrew2007
author_rank: Newbie
timestamp: May 16, 2019, 10:22:51 am
content: Thanks very much ataradov, it does look like an inductor. 😉3225 series (1210), the Panasonic one's have the same marking's too.No marking's on the silk screen.
Component Identification - Page 1
Forum section: electronics / beginners

author: Kinetic_Andrew
author_rank: Newbie
timestamp: April 06, 2023, 01:56:17 am
content: I am looking for help identifying this component. The one in the center with the copper spiral. Its on the circuit board for a Lincoln key FOB, that was badly corroded. I do not have continuity through it. Any help is appreciated.

author: golden_labels
author_rank: Super Contributor
timestamp: April 06, 2023, 04:54:16 am
content: An SMD inductor of some small value, air core. Either a choke or, together with the capacitor north-west of it, it forms an LC filter of some kind.Unfortunately, just like with SMD capacitors, those have no markings. Since it is transparent, you may try estimating the inductance fromthe formula for flat spiral, but at this scale this will be a very rought estimate. It will also tell you nothing about its other properties, which may be relevant.
Component Identification - Page 1
Forum section: electronics / beginners

author: Hendrik
author_rank: Contributor
timestamp: October 07, 2025, 10:37:44 am
content: Hello,I am trying to repair an IR remote control. The device is about 17 years old.The component in question has a SOT-89-3 package with "AA P76" markings.Pin 1 is input of a voltage divider (12k & 1k)Pin 2 is Vout feeding an Atmel microcontroller capable of up to 5.5V inputPin 3 is VinVin is fed by 4xAAA batteries in series at about 6V.All my research led me to these voltage detectors:https://product.torexsemi.com/en/system/files/series/xc61f.pdfBut the pinout does not match and I can't find any more suitable ic from these markings.When manually feeding 4.2V at Pin2 and 6V at Vin the remote control is functional.Anyone knows what type of component this is? I have never seen or used a Voltage Detectors (if thats what it is) but from the position it would make sense I guess.Kind regards,Hendrik

author: jwet
author_rank: Frequent Contributor
timestamp: October 08, 2025, 04:04:34 am
content: Its a high beta PNP transistor being used to manage power. The uP can run on any voltage from 3-6V- no regulator is required, this PNP just lets battery current flow when a button is pressed or when the unit is active. The diode D15 is used to allow the uP to keep power on after a button is touched, etc.The designator T? is a designator for a transistor, not an IC. Its a PNP transistor that is used as a power switch. The transistor is a bit grunty because the LED's draw some real currents. Pin 1 is the base, pin 2 is the collector and pin 3 is the emitter. Normally the base is pulled up with the 12k. When any button is pressed,- T2 (an NPN) is turned on and pulls on the 1K, R29 to sink current turning the PNP on. Some thing with a beta of 50-100 and an Ic max of 500 mA peak, you can measure. Package is SOT-89-3. Shouldn't be hard, look at Digikey, Mouser, Farnell, etc.

author: amyk
author_rank: Super Contributor
timestamp: October 08, 2025, 05:17:00 am
content: BCX51?

author: Hendrik
author_rank: Contributor
timestamp: October 08, 2025, 02:55:54 pm
content: Thank you guys for the help. I wasn't so aware of the T designator for bipolar transistors, more used to Q.I still have some PNP power transistors from an e-bike display repair:https://www.lcsc.com/datasheet/C41375139.pdfthat seem to work good so far.

author: jwet
author_rank: Frequent Contributor
timestamp: October 08, 2025, 05:55:49 pm
content: The T? thing for transistors is sort of an Asian consumer electronics thing- it was also used in old european stuff. The US's Q? designator is sort of a strange letter for this- don't know the story.