hybridfree/eevblog-posts huggingface dataset:
Tesla Model 3 (teardown, motherboard, etc.) - Page 1
Forum section: electronics / beginners

author: 13hm13
author_rank: Frequent Contributor
timestamp: April 21, 2018, 06:53:25 pm
content: Munro & Associates, Inc. (Michigan, USA), tore down two Tesla Model 3's in order to produce their massive report (for sale, in the B2B industry).This video is bit long, but some good discussion and some views of the teardown:Highlights include:03:00 - Tesla Model 3 Teardown Analysis14:55 - The Good Stuff: Model 3 Automatic Drive Modules (motherboard)26:46 - Are the pieces good? Door Panels, Exterior, etc.29:00 - Model 3 Battery: Intricate Magic42:55 - Doctor Data44:55 - Mechanics of the Model 3
Pierce Crystal Oscillator component specification - Page 1
Forum section: electronics / beginners

author: unknown_h
author_rank: Contributor
timestamp: June 29, 2022, 02:46:40 pm
content: Hi all,my google and other research skills have failed me on this one for some time. I am trying to find out how to specify the components in a like the generic one shown bellow.I have a finished circuit using this design shown in the attached image and I am just trying to figure out how they got the end result.

author: bob91343
author_rank: Super Contributor
timestamp: June 29, 2022, 06:03:30 pm
content: The coupling capacitor needs to be low reactance at the operating frequency, and the RFC needs to be high reactance. The source resistor is current limiting and gives some negative feedback to soften distortion. The bypass capacitor needs to be low reactance. The trimmer capacitor needs to adjust the frequency precisely according to crystal specification. The 1 Meg resistor providea a path for minor currents and needs to be high in value compared to other circuit constants.In other words, nothing is critical and common sense rules.
Test - Page 1
Forum section: electronics / beginners

author: griffinadams
author_rank: Newbie
timestamp: July 13, 2023, 04:40:39 pm
content: hello I guess I can't delete my own posts. Ooops.

author: RoGeorge
author_rank: Super Contributor
timestamp: July 13, 2023, 05:21:46 pm
content: You can delete your own posts when they are somewhere in a topic, but not when the post you want to delete is the one that started a new topic (can not delete your own OP - Opening Post). It is possible, however, to move a topic you created (together with all its replies) in another EEVblog category/subforum.Also specific to EEVblog, there are very few moderators and they are busy with spam or other problems, they usually don't have bandwidth for personal requests, like please delete/move my post, or please merge these two topics, or split this long one, etc.Welcome to EEVblog.No problem you created a test, though duplicated topics is against the forum practices:https://www.eevblog.com/forum/chat/forum-rules-please-read/

author: griffinadams
author_rank: Newbie
timestamp: July 13, 2023, 07:26:13 pm
content: Good to know. Thank you.
Test a high-voltage current regulator? - Page 1
Forum section: electronics / beginners

author: torch
author_rank: Frequent Contributor
timestamp: March 03, 2016, 02:59:40 am
content: I bought a batch of 5 "IXYS10M45S" switchable high-voltage current regulators for a little tube-technology project using a proven circuit. I don't think they work. The circuit in question is very simple and I have verified my version correctly follows the schematic. I have the correct resistances between gate and cathode and between cathode and ground. I have power at the anode and a signal at the gate. There is a very brief surge of current at the moment the circuit is energized and then no current flow thereafter.My Carl Heinz inspired transistor checker claims 4 of them are an "N-E-MOS" (Enhancement mode N-channel mosfet, I believe) and the 5th is a diode. The diode check function on my meter confirms that 5th one is different from the rest. So at least one of them must be bad.Thedata sheetis a little sketchy about what exactly is inside, minimum voltage, etc. but at the bottom of page 2 is an example circuit for voltage control of the current regulation. So I took one of the "good" ones, and hooked it up to the bench power supply. I bonded Channel 2 + to Channel 1 -, connected Channel 1 + to the anode, Channel 1 - to the cathode and Channel 2 - to the gate. I set Channel 1 to 14v (one spec references a VDas low as 10v - I'm guessing the anode was called "drain" at one point in the development phase -- so I took that as a minimum anode voltage), and started Channel 2 at -5 volts (should be "off" at that voltage).I slowly reduced Channel 2 to 0, but there was no current flow at all. I tried again with incrementally higher anode voltages, up to the 31v my supply can deliver but other than that initial momentary in-rush on powering the circuit, I never saw any current flow.Before I go after the vendor, is there any obvious flaw in my test procedure?
Test Equipment for current supply and voltage measurement - Page 1
Forum section: electronics / beginners

author: JamesHowlett
author_rank: Contributor
timestamp: October 09, 2014, 07:16:37 pm
content: Hello,I have a simple question, which can be answered almost everybody in the forum. I want to supply a dc current to a material from two contact and measure the voltage from another two contact, sort of an I-V measurement. What sort of equipment do I need for it?I made my small research and I found couple of alternatives such as, keithley 2400 SMU and adjustable power supplies form keithley and Agilent. One is a SMU and the others are power supplies and as far as my knowledge concerned, I should say that I am confused a little bit.As the requirement:setting a current value and increasing the value with steps until the end value with defined stepsmeasuring the voltage simultaneously with the same equipmentlogging the data with the pc to calculate the resistance of the materialI know there are lots of answers depends on the precision and the voltage-current ranges, but I ask to have an rough idea about the test equipment.Cheers!

author: w2aew
author_rank: Super Contributor
timestamp: October 10, 2014, 02:58:16 am
content: Quote from: JamesHowlett on October 09, 2014, 07:16:37 pmAn SMU is the simplest way to do this, because it allows you to source a specific current or voltage, and measure the resulting voltage or current. You can accomplish some of the same functions with a current limited power supply and DMM, but you have to set it all up manually and you might not be able to achieve 4 quadrant operation. A SMU like the 2400, 2450, etc can do this easily, as well as sweep the stimulus to generate an IV curve etc.

author: JamesHowlett
author_rank: Contributor
timestamp: October 10, 2014, 08:14:30 pm
content: Quote from: w2aew on October 10, 2014, 02:58:16 amThanks a lot! Now I should find a budget SMU, Keithley is relatively expensive, but I will call the companies on Monday anyway to see whether they can offer something less expensive and more application specific(voltage and current limits wise).just out of curiosity, isn't there any voltage or current source which can be programmed to scan a current range?Regards
Test Equipment Manuals-Just A Rant! - Page 1
Forum section: electronics / beginners

author: riverrat373
author_rank: Contributor
timestamp: January 09, 2015, 05:25:30 pm
content: Just a rant!I'm not a complete novice when it comes to electronic theory or building projects, but I am new to some test equipment (oscilloscopes, function generators) and I cannot figure out why Chinese manufactures of test gear do not hire someone to write their manuals that actually know English! Trying to understand the convoluted language in their manuals is driving me crazy! You would think that at least the distributors and retailers would make an effort to try to convince the Chinese to improve their manuals or, if nothing else, supply their own manuals with the equipment.Can anyone out there suggest a couple of good books for learning how to use electronic test equipment?

author: Yago
author_rank: Frequent Contributor
timestamp: January 09, 2015, 06:31:10 pm
content: Look at the top of this forum section, there's a vid for scopes, and a collection of other learning material.

author: katzohki
author_rank: Frequent Contributor
timestamp: January 09, 2015, 08:06:43 pm
content: Quote from: riverrat373 on January 09, 2015, 05:25:30 pmBecause that would cost money!

author: free_electron
author_rank: Super Contributor
timestamp: January 09, 2015, 08:18:22 pm
content: Quote from: riverrat373 on January 09, 2015, 05:25:30 pmlogically speaking, there are more chinese speakers in the world than any other language so we should adapt. Wu chi ka hue !

author: riverrat373
author_rank: Contributor
timestamp: January 09, 2015, 08:40:58 pm
content: Quote from: Yago on January 09, 2015, 06:31:10 pmThanks for pointing that out.

author: Fsck
author_rank: Super Contributor
timestamp: January 09, 2015, 08:41:05 pm
content: Quote from: free_electron on January 09, 2015, 08:18:22 pmbut I wonder if that holds true of their customers instead of the general populace.

author: pickle9000
author_rank: Super Contributor
timestamp: January 09, 2015, 08:47:01 pm
content: Start with this.https://www.eevblog.com/forum/beginners/oscilloscope-training-class-%28long%29/

author: pickle9000
author_rank: Super Contributor
timestamp: January 09, 2015, 08:53:34 pm
content: Quote from: Fsck on January 09, 2015, 08:41:05 pmManuals typically show equipment set ups and not much more. When it comes to Chinese manuals, if you could prove that it increases sales they would all have excellent ones. Uni-t manuals are normally good examples of what is possible.
Test jig for solid state relay - Page 1
Forum section: electronics / beginners

author: dareswitch
author_rank: Newbie
timestamp: May 28, 2019, 05:19:46 am
content: Hello All,I'm very new to this forum and still working out my electronics skills in designing.Can some one please help me to build a circuit to test a Solid State Relay unit D1D40.Have a circuit with - SPDT switch and 4 LED (companied with ressitors)and then used 8 x 180Ohm Resistors at the load end of D1D40 relay which get very hot upon operation and i want to come up with a solution for this problem .Please see 4 LED are used for below purposes in my circuit-1st LED - Power ON indication2nd LED - to indicate whether the Relay is Active3rd LED - to indicate Fail open4th LED - to indicate FAIl ClosedBUt i need something simple but everything covered.Kindly suggestThanks

author: soldar
author_rank: Super Contributor
timestamp: May 28, 2019, 11:23:48 am
content: Much simpler and better to just connect an incandescent lightbulb as a load and drive the input with a suitable circuit and a switch.

author: dareswitch
author_rank: Newbie
timestamp: May 28, 2019, 10:39:20 pm
content: Thanks but we need a test Circuit to check the relay functionality as it is how it is meant to be

author: soldar
author_rank: Super Contributor
timestamp: May 28, 2019, 11:19:48 pm
content: How are you going to test a SS relay without connecting a real load? I can't see how that is practical.
Test jig to measure rail voltages - Page 1
Forum section: electronics / beginners

author: joeyjoejoe
author_rank: Frequent Contributor
timestamp: November 24, 2023, 02:24:10 pm
content: I'm building a bed-of-nails test jig for some boards. I'd like to measure the 3.3V, 5V and 24V rails.My initial thought is to use voltage dividers to bring everything down to the nominal ADC range of whatever MCU I'm using is. So if my ADC has a perfect range of 0-3.3V, I'd divide the 5V rail so that 5V is around 1.6V.My thought was to use a MCU so I can have a go/no-go status LED for the 3 rails. However, I can probably do this with discrete logic, probably involving opamps? I'd then need reference voltages for those 3 rails. (An AVR is a buck or two and quite easy for me to do in software versus fumbling through hardware)Any thoughts or other ideas are appreciated

author: MarkT
author_rank: Frequent Contributor
timestamp: November 24, 2023, 09:52:12 pm
content: Discete logic involving _comparators_, surely? Comparators like the 339 with open-collector outputs allow simple logical AND by paralleling the outputs which is nice. Use two units to make a window comparator, parallel these for each rail...

author: Zero999
author_rank: Super Contributor
timestamp: November 24, 2023, 10:47:26 pm
content: What's the desired tolerance?Window comparators are required to do this properly.

author: David Hess
author_rank: Super Contributor
timestamp: November 25, 2023, 01:19:03 am
content: Window comparators are the common solution for this. They can be made from comparators like the LM393 dual differential comparator or from operational amplifiers configured as comparators.

author: shapirus
author_rank: Super Contributor
timestamp: November 25, 2023, 01:36:14 am
content: Quote from: joeyjoejoe on November 24, 2023, 02:24:10 pmCan be just one reference and a few resistors in series to set the required reference points, as long as the inputs of the comparators have high enough impedance. Watch out for the resistor tolerances though (and/or pick and match parts manually) and, if the requirements are tight, TCR.

author: joeyjoejoe
author_rank: Frequent Contributor
timestamp: November 26, 2023, 10:57:45 pm
content: Thanks everyone. Actually I'm realizing now, I will be supplying the 24V from the bench for the test jig. The 5V and 3.3V rails are derived from that so I can use the 24V as a reference.However, the for part count needed - I think an ADC on an AVR will be simpler and adjustable via software very easily with whatever the actual resistor values end up on the board?
Test leads and clamp measurement? - Page 1
Forum section: electronics / beginners

author: bitwelder
author_rank: Super Contributor
timestamp: May 22, 2016, 10:22:03 am
content: The instructions of the Uni-T UT210E (small current clamp meter with leads to measure voltage/resistance) warn in the AC/DC current measurement section:QuoteI get that the accidental contact with the test leads may disturb the current clamp measurement, but is there really a risk of electric shock if somebody touches them?What are the voltage levels induced in the instrument while using the clamp?(Nevertheless, it IS a good idea to remove the leads anyway when they are not used)
Test leads on a TQFP package ? - Page 1
Forum section: electronics / beginners

author: gjh
author_rank: Contributor
timestamp: April 15, 2022, 07:26:46 am
content: Whats the proper way to hook up test lead just to a few outputs on a TQFP package (atmega 2560). Found something like this which might do ?https://alitools.io/en/showcase/micro-ic-clamp-10pcs-set-sop-soic-tssop-tsop-ssop-msop-plcc-qfp-tqfp-lqfp-smd-ic-test-chip-pin-mini-chips-adapter-socket-32589469448Just want to hook up 3 ADC outputs to a scope to see if they are still alive.Have some enamel 0.25mm wire which I might be able to careful temporary solder on to but seems like a pain.

author: tepalia02
author_rank: Regular Contributor
timestamp: April 15, 2022, 08:32:52 am
content: You need TQFP burn-in sockets. The Micro IC clamp that you've shared will also work.

author: janoc
author_rank: Super Contributor
timestamp: April 15, 2022, 08:47:32 am
content: Quote from: tepalia02 on April 15, 2022, 08:32:52 amThe OP has the chip soldered in. How exactly is a test socket going to help them with the problem? Those sockets are meant for programming/testing the chipsbeforethey are soldered into boards, not after.Those micro clamps work (I have also a set, in case I will need to do this) but they can be a pain to set up and it is easy to short two adjacent pins with them.The easiest way is to find a nearest via or a passive component pad on the track in question and solder your wire there - those are usually a lot larger and easier to access than individual pins of the TQFP. In the worst case you can (very carefully!) scrape off a bit of soldermask on the track and solder directly to it too.Of course, there are also specialized probing solutions like this:https://sensepeek.com/(There was also a nice open source kit made out of aluminium extrusions with various types of holders and attachments but can't find it now).However, if this is for a one off thing and you probe like this once in a blue moon, then you likely don't have the probe holder and buying/making one would be an overkill.

author: Ian.M
author_rank: Super Contributor
timestamp: April 15, 2022, 09:45:40 am
content: As Janoc has already pointed out, its a PITA to set up micro-probes so they are stably located and safe to use, IMHO more so than the few tens of seconds per pin it takes to prepare and solder on 30 AWG Kynar wirewrap wire or fine magnet wire if you need to go thinner. The probes only come into their own if its imperative that you don't solder to the board.Do yourself a favor and mount a female 0.1" pitch header on its side, on 3M VHB tape, somewhere convenient (e.g. at a nearby unpopulated area of board edge) to give you an easily accessible place to terminate the other end of your breakout wires and connect to them. You can then disconnect the test jig leaving the breakout wires in place, crucial if you ever need to clear your bench and do something else while waiting for parts. If your hacked in breakout wires are for an ICSP or debug port, consider tacking them down with a suitable adhesive or tape and leaving them permanently if its likely to cross your bench again.
Test Leads - Page 1
Forum section: electronics / beginners

author: TorqueRanger
author_rank: Frequent Contributor
timestamp: November 21, 2012, 01:03:59 am
content: I just picked up my first power supply and now I need test leads .. So I wanted to see what you guys are using because either I am going to build or buy which every is cheaper ...Thanks ahead of timeJAy

author: george graves
author_rank: Super Contributor
timestamp: November 21, 2012, 02:17:49 am
content: Plenty of cheap stuff on ebay if you're short on funds and just need something to hold you over.It's the usual quality vs price thing.
Test load regulation of regulator: just hook electronic load between Vout & gnd? - Page 1
Forum section: electronics / beginners

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: January 10, 2022, 06:44:11 pm
content: I want to test load regulation of a bucker converter IC on a PCB. Can I just hook an electronic load up to Vout and ground of the IC? Or must I also disconnect the original load of the circuit in the PCB as well?

author: TimFox
author_rank: Super Contributor
timestamp: January 10, 2022, 06:50:50 pm
content: One measure of load regulation is to see the delta of output voltage with a delta of load current, so measuring the difference with and without an additional load works for that.
Test multimeter min/max or peak response time - Page 1
Forum section: electronics / beginners

author: SquaL
author_rank: Newbie
timestamp: October 26, 2017, 07:37:43 pm
content: Hi, how would I go about testing my meters min/max response time? Fluke list my meters peak min/max response time as 250 µS. I have other multimeter that do not provide this detail.

author: Awesome14
author_rank: Regular Contributor
timestamp: October 26, 2017, 07:47:48 pm
content: You'd require an intimate knowledge of the meter and you'd need to connect to the insides of it. It's hardly a practical possibility.

author: w2aew
author_rank: Super Contributor
timestamp: October 26, 2017, 08:25:47 pm
content: Quote from: SquaL on October 26, 2017, 07:37:43 pmOne way to test it would be to use an adjustable single-shot (monostable) pulse generator - easily made with a 555. Set the meter to record the Peak DC voltage, then hit it with various pulse widths from the monostable and see what pulse width gives you the correct peak result. Of course, you'll likely have to have a scope to measure the pulse width. Or, maybe do it with a programmable micro...

author: stj
author_rank: Super Contributor
timestamp: October 26, 2017, 10:31:26 pm
content: wouldnt it be in the datasheet of the control chip?

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: October 26, 2017, 11:39:33 pm
content: Quote from: stj on October 26, 2017, 10:31:26 pmWell, it SHOULD be there.With the slight caveat that the filtering applied to the individual implementation of a meter using this chip is not included.So it would be a lot of analysis work on various schematics, if available.Basic possibilities exist in measuring the delay of the annunciator segment or the beeper.In conjunction with a suitable signal source, as stated above.
Test plugs for pin header holes  - Page 1
Forum section: electronics / beginners

author: hrsx
author_rank: Newbie
timestamp: December 24, 2023, 08:08:00 pm
content: Hi, I have a board with a standard 2.54 mm hole pattern for a pin header (2x8 pins). I am looking for something that can be directly plugged into these 1 mm holes without soldering, kind of like a 1 mm banana plug. This is to be able connect to the board for debug purposes later on. There is no room to install a connector and since there will likely be very few uses of the connection, it is not justified to make the housing larger just for this.Does anyone know a product like that?

author: wraper
author_rank: Unknown
timestamp: December 24, 2023, 08:18:21 pm
content: Why not just use wide pogo pins that don't go through the holes? If you want holes at all and not just test pads.

author: hrsx
author_rank: Newbie
timestamp: December 24, 2023, 08:22:36 pm
content: Wouldn't I have to constantly hold them down? I'm imagining something more like a banana plug, that is spring-loaded to hold on its own. It is a finished board I buy with the holes already in, so I can't change them to anything else.

author: wraper
author_rank: Unknown
timestamp: December 24, 2023, 08:25:08 pm
content: I personally make very simple fixtures that hold boards in fixed position. Also you could do something like this

author: wraper
author_rank: Unknown
timestamp: December 24, 2023, 08:26:26 pm
content: Here is off the shelf solutionhttps://www.tag-connect.com/info

author: hrsx
author_rank: Newbie
timestamp: December 24, 2023, 08:56:19 pm
content: The tag-connect requires the PCB to be designed to be used with it, so it's not an option for my application.The self made solution but with oversized pogo pins is an option. But it is still more work than buying something that just plugs in. If that exists.
Test probes recommendation - Page 1
Forum section: electronics / beginners

author: Uni
author_rank: Newbie
timestamp: October 21, 2018, 09:23:26 am
content: Hi guysI have a frequency counter (HP5315a) but no probes.Im going to use this for calibration purposes of audio gear only (synthesizers, drum machines, etc etc)I’m a bit confused as to which probes to use.Would anyone recommend something ?Can I use this one maybe ?https://www.ebay.com/itm/Hantek-PP-150-X1-X10-100MHz-Oscilloscope-Clip-Passive-Probe-BNC-Port-Probe/123394470806?pageci=4d2f85c2-47f1-4233-9f91-82b9c20fa620&epid=1958370226

author: MiDi
author_rank: Frequent Contributor
timestamp: October 21, 2018, 09:43:57 pm
content: You should be fine with bnc to alligator-clips for audio range, no need for an oscilloscope probe for high bandwidth.

author: tkamiya
author_rank: Super Contributor
timestamp: October 22, 2018, 04:14:34 am
content: I agree with alligator clips for audio use. You can also have an unterminated BNC connector/cable and solder when necessary. Probes are usually not used for frequency counters.

author: Uni
author_rank: Newbie
timestamp: October 22, 2018, 10:57:45 am
content: I seeThanks for the replies!

author: rdl
author_rank: Super Contributor
timestamp: October 22, 2018, 04:35:02 pm
content: This is basically the same as what I use most of the time. I got all mine separately though, and from different sources, so I can't vouch for the quality of these.https://www.ebay.com/itm/BNC-to-Alligator-Clips-BNC-to-Mini-Test-Clips-BNC-to-BNC-Cable-Oscilloscope-Test/113322032324

author: Uni
author_rank: Newbie
timestamp: October 22, 2018, 05:54:07 pm
content: I bought this one:https://m.elfadistrelec.no/no/bnc-plug-ic-crocodile-test-lead-rod-svart-rnd-lab-rnd-350-00011/p/30112706Does it look right ?
test results - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: November 23, 2021, 05:52:26 am
content: hi all,can anyone explain these readings i get on my component tester,its testing an old pnp germainium,im wondering about leakage,i assume the uf is the junction diode drop,and the B is hfe,not sure of the others tho.

author: m3vuv
author_rank: Super Contributor
timestamp: November 23, 2021, 05:54:06 am
content: and another pic

author: ataradov
author_rank: Super Contributor
timestamp: November 23, 2021, 06:07:00 am
content: It is a PNP transistor. Emitter, Base and Collector pins are 1, 2 and 3.Transistors Beta (Hfe) = 93, forward voltage 203 mV.ICEO (not 0) is usually a collector-emitter leakage current with the base open.

author: m3vuv
author_rank: Super Contributor
timestamp: November 23, 2021, 06:51:23 am
content: would you say that is bad then as it leaks,what sort of leakage current is normal for a working transistor then?

author: ataradov
author_rank: Super Contributor
timestamp: November 23, 2021, 07:06:16 am
content: 10 uA is perfectly fine. I doubt that thing can meaningfully measure currents that low, so I would discard that measurement. Just treat it as "OK".
Test Triac with Multimeter - Page 1
Forum section: electronics / beginners

author: 2X
author_rank: Frequent Contributor
timestamp: April 01, 2020, 07:43:49 am
content: Hello, I am measuring the triac BT136 and some other triacs in order to find a way to test them with multimeter. If I measure the triac between the Teminal 1 (Positive lead of multimeter with the Gate pin together) and Teminal 2 (negative lead of multimeter) the multimeter doesn't show anything but if I reverse the multimeter leads it measures ok. I can't understand hy happens this because the triac is a bidirectional component. I have made a diagram in the below picture of how and what I measured. Does anyone knows why this is happend?

author: Zero999
author_rank: Super Contributor
timestamp: April 01, 2020, 11:57:04 am
content: Quote from: 2X on April 01, 2020, 07:43:49 amYes, this is exactly what you should expect to happen. Your equivalent schematic of a TRIAC is incorrect. A TRIAC will trigger when a current flows through the gate to terminal 1. If the gate is connected to terminal 1, then no current will flow through the gate and it won't trigger. If the gate is connected to terminal 2, then current will flow from terminal 2, through the gate to terminal 1.https://en.wikipedia.org/wiki/TRIAC

author: 2X
author_rank: Frequent Contributor
timestamp: April 02, 2020, 03:15:22 am
content: Thank you very much for the help and the link.
Testing 2N5193 ? - Page 1
Forum section: electronics / beginners

author: Crambone
author_rank: Frequent Contributor
timestamp: July 17, 2023, 07:39:45 pm
content: How can a 2N5193 TO-126 package be tested?https://z3d9b7u8.stackpathcdn.com/pdf-down/2/N/5/2N5193_Central.pdf

author: Benta
author_rank: Super Contributor
timestamp: July 17, 2023, 07:46:37 pm
content: Just like any other PNP transistor. Nothing magical about a 2N5193.

author: TimFox
author_rank: Super Contributor
timestamp: July 17, 2023, 07:58:43 pm
content: What parameters of the 2N5193 do you need to measure/test?Except forfT, which is not very high, everything else on the datasheet is a DC value.The thermal specs are basically from the design of the package.
testing a 3500V 6.5mA constant current PSU - Page 1
Forum section: electronics / beginners

author: tolland
author_rank: Newbie
timestamp: August 04, 2014, 08:47:24 am
content: Hi,I have been given a JDSU 380T psu for a Melles Griot 05-LHP-991 HeNe laser. However it blows the 500mA fuse when powered up.I suspect the power brick has been damaged, but I'd like to test it without the laser attached to determine whether it is the laser or the PSU that is faulty.It would seem I would need a 3500V/6.5mA=538.5 k Ohm load that can handle 22 watts to simulate the 6.5mA load of the laser.Is that something I can make up? (bucket of water or something.... ;-)Cheers,Tom

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 04, 2014, 09:01:08 am
content: HeNe PSUs do not put out that sort of voltage/current at the same time.The 3.5kv is a starting supply, and is very low current. Once struck, the tube runs at around 6-700V.It is safe to run without the tube for short periods, as this is what happens before the tube strikes.Chances are it's the PSU. A failed tube wouldn't make the PSU draw excess current unless there is an external short, even then chances are the PSU would limit.

author: mij59
author_rank: Frequent Contributor
timestamp: August 04, 2014, 09:02:30 am
content: Hi,Sounds like nasty stuff.Before you continue, do some reading on the subject, e.g.http://donklipstein.com/laserhps.htm#hpsrtc0] http://donklipstein.com/laserhps.htm#hpsrtc0

author: SeanB
author_rank: Super Contributor
timestamp: August 04, 2014, 05:17:45 pm
content: You could run it with a 4ft flourescent lamp as a load. That will strike and run at around 60-90V when lit. If it is blowing fuses that violently though I would guess the input bridge rectifier, capacitors or something on the primary side is shorted. These power supplies are quite happy to run into a short circuit on the output for a minute or so. open it up and look at the unpotted sections to see the cooked stuff.

author: edpalmer42
author_rank: Super Contributor
timestamp: August 04, 2014, 07:39:17 pm
content: How do you have that power supply wired?You don't say where you are, but your use of a 500 ma fuse suggests that you live in a 230 V area. So why do I see a white wire going from the power supply to your fuse panel? The white wire is only for 115 V power.I also don't see a ballast resistor. Is it internal to the laser or the connector?Ed
Testing a Diode - Page 1
Forum section: electronics / beginners

author: cmccul002
author_rank: Newbie
timestamp: November 14, 2016, 01:07:45 am
content: Greetings all, fairly new to component level electronics repair. II have a scrap PCB board i was just poking around with a multimeter, testing components.New to testing diodes, read up on it and was testing some on this PCB just to familiarize myself.So i tested a few with my multimeter set to "diode" mode which is also a continuity tester. So i tested a few, and got the normal readings with probes on the correct leads and reversed.During this testing, the continuity "Beep" did not come one, then i came across this one diode where the reading was the same with the probes normal and reversed "0.660" and the continuity "beep" came one both ways.I assume this diode is bad?

author: Rerouter
author_rank: Super Contributor
timestamp: November 14, 2016, 01:14:08 am
content: a diode drop can be between 0.25 (lowest i have ever seen them commercially) to 1.1V for some of the really cheap ones, so 0.66 seems reasonable,The beep function you are hearing is called the continuity buzzer, generally used to check that 2 points are on the same wire, now the threshold where that buzzer will sound should be specced in the manual, it just means the voltage across the 2 points is under that threshold,now as for a diode that reads the same way in both directions, it is likely caused by you measuring it "In-Circuit" and there may well be another diode in anti-parrellel somewhere else on the board, if you lift one of the diodes legs, you may find it only conducts in one direction.It could even be a resistor in parrellel, as all the diode check function does is output a fixed current and report the voltage, a resistor could just as well drop that voltage for the test current before the diode gets a chance to turn onIn general a diode will fail either shorted (common in zeners), or open (common in conventional) and rarely is a difference of 0.72 vs 0.66 much of a concern

author: tautech
author_rank: Super Contributor
timestamp: November 14, 2016, 01:44:22 am
content: Quote from: cmccul002 on November 14, 2016, 01:07:45 amYep, you'll often get this when testing "in circuit".When you do, the only way to be sure of the diode'srealstatus is to get out the soldering iron and lift a leg.
Testing a LT1171CT High Efficiency Switching Regulator - Page 1
Forum section: electronics / beginners

author: steve632717
author_rank: Newbie
timestamp: March 25, 2014, 10:40:34 am
content: Hello, I am after a bit of help. I have a MEADE CCD power unit that is not powering up my CCD. I have checked all the voltages to the DIN plug and I am getting 5 volts to all the pins apart from one which is only supplying 800mV. I have traced this circuit back to a 5V reg, then back to the LT1171CT High Efficiency Switching Regulator. I have got supply voltage going into the LT1171CT (PIN 5) but no voltage coming out of the LT1171CT (PIN 2), I have check the ground circuit and all looks ok. Can someone please tell me how to check the switching side of this chip.PS. I did supply a independent 10v to the 5v reg. and the CCD powered up ok.Thanks for any help.Steve

author: BravoV
author_rank: Super Contributor
timestamp: March 25, 2014, 10:42:20 am
content: When it comes to asking help especially in switching power supply problem ...... post your schematic AND the real photo of your working circuit.
Testing a multimeter - Page 1
Forum section: electronics / beginners

author: Bigknobby
author_rank: Newbie
timestamp: December 30, 2015, 02:48:50 pm
content: Thanks in advance for the help. I have an old Craftsman digital multimeter and suspect it might not be working properly, how do I test all the functions of the meter to determine if it is working. Thanks again.

author: Simon
author_rank: Unknown
timestamp: December 30, 2015, 03:13:13 pm
content: well most multimters convert any measurement into voltage, so your best bet is to start testing the voltage reference. Do you have a fairly accurate reference to start with ? how accurate do you need to be ?

author: Bigknobby
author_rank: Newbie
timestamp: December 30, 2015, 03:30:48 pm
content: The meter is a Craftsman 82309 (I don't have a manual, and can't seem to find one on the internet). When I use it to test AC/DC volts (110VAC source/12VDC source) the readings seem to be accurate. With impedance selected, I just get a "0" displayed regardless of what I check. The other settings I don't know how to use (lack of knowledge and a manual).

author: Simon
author_rank: Unknown
timestamp: December 30, 2015, 04:09:44 pm
content: sounds like the ohms side of things may be damaged

author: Bigknobby
author_rank: Newbie
timestamp: December 30, 2015, 07:29:45 pm
content: Thanks for the help. Do you have a good source for learning to use all the functions of my multimeter. I attached a photo of it.

author: nanofrog
author_rank: Super Contributor
timestamp: December 30, 2015, 08:36:28 pm
content: Quote from: Bigknobby on December 30, 2015, 07:29:45 pmType in "how to use a multimeter" in a search engine, and you'll get a lot of stuff come up.Sorting through the good and bad can be a bear, so here's a starting point (from Marton Lorton, akamjlorton).Follow the links to the others in the series he made (2 on current and 1 on resistance and continuity). He's also made an advanced series of videos on diodes and such that will also be of interest.Other members have made videos, such asw2aew, might be of interest as well (link = his youtube page).
Testing a PCI card - Page 1
Forum section: electronics / beginners

author: rthorntn
author_rank: Frequent Contributor
timestamp: April 22, 2019, 08:53:34 am
content: Hi,Is there such a thing as a PCI test jig, basically a way to power a PCI card so that you can test the card voltages?Thanks.Richard

author: Shock
author_rank: Super Contributor
timestamp: April 22, 2019, 11:49:15 am
content: Quote from: rthorntn on April 22, 2019, 08:53:34 amPCI Express? Asked this question myself noone was particularly forthcoming on brands that work well but there are PCI risers and extenders, some are on long cables, some are card extenders, some are cable to PCB sockets, this would allow you access to the card externally.For 32 bit PCI, PCI-X and 64 bit PCI search under those terms with the words riser or extender. You can also salvage angled risers from half height PCs.There are also a variety of PCI card testers, google images is a quick way to see what is out there.
testing a schottky diode - Page 1
Forum section: electronics / beginners

author: ewcc
author_rank: Contributor
timestamp: August 18, 2020, 08:02:49 am
content: Hi,For a regular diode, I use diode mode on the dmm, and the red probe on anode, black on cathode. I figured a schottky diode would be the same; but when I try that on this sb3100, I get a beep.Does this mean this diode is dead or am I testing it wrong?ThanksEd

author: ggchab
author_rank: Frequent Contributor
timestamp: August 18, 2020, 08:47:36 am
content: Normally, the dmm should simply indicate a lower forward voltage for the Schottky diode.My dmm beeps when I short the leads in diode mode. Did you try inverting the leads ? Do you also get a beep ? Then, the diode might be dead.

author: ewcc
author_rank: Contributor
timestamp: August 18, 2020, 09:21:27 am
content: Quote from: ggchab on August 18, 2020, 08:47:36 amI also get a beep when I short the leads in diode mode. When I invert the leads, I also get a beep.So I guess this diode is dead.Thanks ggchab and blueskull!Ed

author: wraper
author_rank: Unknown
timestamp: August 18, 2020, 09:43:29 am
content: What matters is what multimeter shows on it's display. Not stupid beep without any context given. FWIW Keysight U1272A in diode mode makes a short beep when diode is connected in forward direction.

author: perieanuo
author_rank: Frequent Contributor
timestamp: August 18, 2020, 10:09:37 am
content: hi,if you hear the beep with the schottky diode measured in circuit, wait some seconds.the beep may be some capacitor charging.for schottky you should see approx 0.2 volts in diode tester mode or less.regards,pierre
Testing a Tektronix 2246 - Page 1
Forum section: electronics / beginners

author: Dustan
author_rank: Newbie
timestamp: October 31, 2012, 06:06:06 pm
content: I have been out of electronics for a few years now and remember faintly there was a self test for this unit but cannot seem to bring it up. Does anyone know the keys to press to get the unit to self test I know the 2465 was like delta and trig button thought there was one on this too but can't remember.
Testing amplifier w/ spectrum analyzer - Page 1
Forum section: electronics / beginners

author: molotov
author_rank: Newbie
timestamp: June 20, 2016, 05:03:20 pm
content: I am designing an amplifier for a piezo based vibration monitor.I want to connect the output of the amplifier to the 50 ohm input of a spectrum analyzer using a standard 50 ohm BNC cable.My circuit is below. Would I just need to put a 50 ohm resistor in series with the output of the instrumentation amplifier?

author: tggzzz
author_rank: Super Contributor
timestamp: June 20, 2016, 05:45:14 pm
content: Quote from: molotov on June 20, 2016, 05:03:20 pmMore or less, but you should take the output impedance of the INA into account, e.g. if the output impedance is 10ohms, then you would add a 40ohm series resistor. Whether or no that matters depends on whether the interconnection is electrically "short" or "long" compared to the signal's wavelength, and that is frequency dependent.But be careful: some spectrum analysers cannot tolerate any DC component, and many are very sensitive to too much input power. Too much of either and the unprotected front-end-mixer is instantly destroyed. Check the spec of your SA.

author: molotov
author_rank: Newbie
timestamp: June 20, 2016, 06:57:34 pm
content: Quote from: tggzzz on June 20, 2016, 05:45:14 pmThanks for the reply.The spectrum analyzer is an HP 3588A and it can tolerate up to 4V DC. So as long as I keep the amplifier supply below +/- 4V I should be OK.The maximum frequency I will be analyzing is 2000 Hz so just matching the impedance with a resistor should be sufficient, right?

author: w2aew
author_rank: Super Contributor
timestamp: June 21, 2016, 01:13:24 am
content: Quote from: molotov on June 20, 2016, 06:57:34 pmThe Ad8220 won't do well driving a 100 ohm load with such a low power supply. However, the good news is that with a 2kHz max frequency, you don't have to worry about impedance matching. That spectrum analyzer has a 1Mohm input impedance setting. Connect it up and go....
testing an s8550 transistor - Page 1
Forum section: electronics / beginners

author: silly sausage
author_rank: Regular Contributor
timestamp: January 25, 2025, 06:51:31 am
content: i am trying to do a quick test of a sot 23 s8550 pnp transistor on a dead litokala lii500 charger using my fluke on diode check mode, with the neg probe to base and pos to collector i get no reading,if i reverse the leads i get base-emitter 0.704v drop and base to collector i get 0.702v drop,I a am trying to test q27 as in this vid, I dont understand russian or whatever he is speaking tho , Is it dead or am i testing it wrong?

author: janoc
author_rank: Super Contributor
timestamp: January 25, 2025, 11:49:20 am
content: Maybe learn about punctuation first. That word salad with no punctuation, no capital letters at the start of sentences, etc. that you wrote is incredibly difficult to understand.Are you measuring this in-circuit? If yes, don't. Desolder the transistor. In-circuit measurements are meaningless unless you 100% understand the surrounding circuitry and can be sure there is nothing in parallel that will affect the reading.If those measurements are out of circuit then you are most likely doing something wrong:- Do you have the pinout correct?- Is that really S8550 and not e.g. S8050? That one is NPN and those measurements would make perfect sense for an NPN transistor.I have never seen a dead BJT transistor that would show reasonable diode drop on base-emitter and base-collector junctions. BJTs fail most often completely short or sometimes open. But if both junctions show reasonable diode drops (0.7V is about right for a silicon transistor/diode) then the transistor is very unlikely to be bad.

author: Jwillis
author_rank: Super Contributor
timestamp: January 26, 2025, 10:18:20 pm
content: You can set the YouTube video to auto translate for the CC(Closed Captions) in the settings. In Settings (The Gear) Click on Subtitles/CC, click Auto-translate and chose your language.The video states that the Y1 transistor in question is a MBT8050 NPN.https://www.s-manuals.com/pdf/datasheet/s/s/ss8050_galaxy.pdf. He did not have the MBT8050, so he replaced it with a MBT2222 NPN. He later calls it a 8550 which is a PNP,https://www.mouser.com/datasheet/2/149/SS8550-118608.pdf, that he replaced with the 2222. The MBT2222 did not supply enough current so he replaces again with a TO92 8550. This makes no sense. Making code for the MBT8550 is Y2https://file.elecfans.com/web2/M00/64/43/pYYBAGMERKWABWMHABkK9bSKvGw303.pdf
Testing APC UPS without recommended batteries - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: August 05, 2022, 03:57:43 pm
content: I have couple of APC UPS (different models with different output power and battery requirements) without batteries and I want to test them if they are working I will buy new batteries for them.Can I use above the rated power for example if required battery is 12v 4A can I use 12v 8A?I have HP-6543 power supply can I use it instead of battery like setting 12v 4A on the power supply and use it as a battery?What other methods can be used to test such UPS.

author: agehall
author_rank: Frequent Contributor
timestamp: August 05, 2022, 07:10:15 pm
content: Yeah, the capacity of the battery won’t matter for testing.You can also use large capacitors to jumpstart the UPS - seen people on YT do this. But imho, it is easier to just hook up batteries.Do note that depending on the model of your UPS, you may have to go in and reset some variables. My APC UPS still thought I had 1 minute of runtime after replacing the batteries and had to have some internal setting changed before it would calculate the runtime correctly.

author: edpalmer42
author_rank: Super Contributor
timestamp: August 05, 2022, 07:34:02 pm
content: I've seen some APC UPSs that will appear dead if they don't have a battery installed. But if you connect a simple little wall wart, it starts up fine. It just needs a tiny amount of battery voltage to allow it to wake up.Once it starts up, you can talk to it, configure it, whatever. It might be able to provide voltage boost and cut functions if those don't need a battery. Some UPSs use the battery for voltage boost, some don't.Larger batteries are fine, up to a point. If you install a huge battery, you might burn out the battery charger circuitry since it would be pumping out maximum current for days trying to charge the behemoth.
testing applicance - Page 1
Forum section: electronics / beginners

author: mrrcomp
author_rank: Contributor
timestamp: October 17, 2023, 07:22:37 am
content: HII want to start measuring voltages on the DC side of a av reciever ., what can i put on the open lines connectors / solder points and under the circuit board that is hanging in mid air so that i dont accidentally touch or short circuit anything?Regardsmrrcomp

author: Gyro
author_rank: Super Contributor
timestamp: October 17, 2023, 10:56:57 am
content: It's not at all clear what you are asking, particularly around "open lines connectors". If you are trying to monitor points on the underside of a PCB and you don't want the risk of a probe slipping and shorting an adjacent track, the normal method is to solder on a short length of wire (snipped resistor lead) so that you can attach a clip type test lead. Always check that you have removed them afterwards.Having a board hanging in mid air while probing it is never a good idea, you should support it to prevent accidents. Is there actiually a fault with the AV receiver? From your post, I am worried that you are going to damage it.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 17, 2023, 12:54:53 pm
content: One way is to (temporarily) solder a shunt resistor into the circuit in combination with a two pin 2.54mm header. Soldering the shunt both ensures a solid connection, and that you can use your DMM on some other part of the circuit without disturbing power delivery.
[SOLVED] Testing AS6C4008 SRAM in a TL866 II ? - Page 1
Forum section: electronics / beginners

author: gmc
author_rank: Regular Contributor
timestamp: April 23, 2022, 11:44:27 am
content: Does anyone know if you can test Alliance AS6C4008 SRAM (DIP32) in a TL866 II+. The AS6C4008 does not show up in the list of chips in the software, but there is a 628512 which has the same pinout and is also a 512K x 8.(AS6C1008 SRAM tests ok in the TL866 as the 68128)I have a suspect SRAM but don't want to test it if it's not compatible and risk destroying it.Datasheet for the AS6C4008https://www.alliancememory.com/datasheets/as6c4008/

author: gmc
author_rank: Regular Contributor
timestamp: April 23, 2022, 07:58:20 pm
content: Found some post on another forum that said the 628512 can be used.Tested with that and it passed on the TL866.Hope this helps someone else in future who has the same query.