V-I Curve tracer / Component tester - Page 1
Forum section: electronics / general

author: Veketti
author_rank: Regular Contributor
timestamp: January 25, 2025, 08:11:07 am
content: Dear All,Does anyone know is there available ready made connection box that can be utilized with Oscilloscope and Waveform Generator to test components in PCBA directly? So basically a box which has lead for waveform generator, leads for oscilloscope channel 1 & 2 and probes for DUT. Also needed internal connection and the 10ohm resistor. This setup is easy to build on breadboard to test leaded diodes etc. but not applicable for testing components on pcb..Thank you

author: andrewtaylor
author_rank: Contributor
timestamp: January 25, 2025, 09:09:16 am
content: The sophisticated ready Made Box ist Sold as e.g. Huntron TR. 1000 and 2000 Models. Clones from CN are available too.The poor man soltuion ist called Octopus circuit, Google gives an Impression. Soldering the 6 components and Put in Box: ist No Rocket sciencen

author: Smokey
author_rank: Super Contributor
timestamp: January 25, 2025, 09:16:43 am
content: Quote from: andrewtaylor on January 25, 2025, 09:09:16 amwow. Huntron Tracker 2000s are over 1K on ebay. for a thing with a CRT.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: January 25, 2025, 09:43:27 am
content: Hello Veketti,Quote from: Veketti on January 25, 2025, 08:11:07 amReady made no, but a schematic to build it as DIY device (see also the attached zip file) :https://www.radiomuseum.org/images/schematic-medium/hameg_gmbh_frankfurt/component_tester_hz65_3_486692.pngQuote from: Smokey on January 25, 2025, 09:16:43 amYes, unfortunately, their price skyrocketed these last years. But there's a reason beyond the basic 'vintage' effect.The CRT version is plainly able to display some weird but meaningful oscillations showing variable (multiple) traces intensities. Also, interesting discontinuities (e.g. tunnel diode) are clearly visible.An LCD display device is just inadequate to show such singularities.

author: Smokey
author_rank: Super Contributor
timestamp: January 25, 2025, 09:45:10 am
content: Quote from: timeandfrequency on January 25, 2025, 09:43:27 amgotcha. and vinyl sounds better too, right?

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: January 25, 2025, 10:00:57 am
content: Quote from: Smokey on January 25, 2025, 09:45:10 amDid you have both versions (CRT and LCD) of the trackers in your hands for a faithful comparison ?

author: kripton2035
author_rank: Super Contributor
timestamp: January 25, 2025, 10:43:13 am
content: this is the low cost option, ready built.https://www.aliexpress.com/item/1005007169046145.html

author: Veketti
author_rank: Regular Contributor
timestamp: January 25, 2025, 01:26:55 pm
content: Quote from: kripton2035 on January 25, 2025, 10:43:13 amWow! Don't even need the waveform generator, just Oscilloscope. This is perfect and affordable price too. Ordered one of these, thanks!I see maybe the CN clone is for example ASA Tracker-3000. Looks to have lots of features, but it aint cheap +500€/$ price range. Didn't find any review of that, but it's ok as it's bit too pricey for me.I know those Huntrons, but agree with Smokey, that they're expensive for that kind of vintage devices. If it were 200$/€ I'd consider.

author: RAPo
author_rank: Super Contributor
timestamp: January 25, 2025, 01:43:14 pm
content: There is anew version with built-in display;-)Quote from: kripton2035 on January 25, 2025, 10:43:13 am

author: kripton2035
author_rank: Super Contributor
timestamp: January 25, 2025, 02:35:19 pm
content: Nice, but it seems very new as I can't find any video online about it...

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: January 25, 2025, 06:07:00 pm
content: Quote from: RAPo on January 25, 2025, 01:43:14 pmThe product page talks about one unique voltage range : 4VReally ?If correct, this would be a serious drawback.Quote from: kripton2035 on January 25, 2025, 10:43:13 amI spotted a similar model about a year ago.This one has four voltage ranges : 0.6, 4, 8 and 16 V, which is quite versatile.However, higher voltages are sometimes useful for Zener and Transil tests and also to detect semiconductors that show up partial breakdown failures.All these models feature an internal sine generator with selectable current limiting resistor.The additional variable level synchronous pulse output, if available, is mainly used to test 3-legged semiconductors in off-circuit test mode.

author: mawyatt
author_rank: Super Contributor
timestamp: January 25, 2025, 06:20:50 pm
content: Here's some links some may find interesting.https://www.eevblog.com/forum/testgear/fooln-around-with-dso-awg/https://www.eevblog.com/forum/projects/dso-awg-based-curve-tracer/We haven't completed the above (yet), however should be an interesting project for someone with an interest.Best

author: Veketti
author_rank: Regular Contributor
timestamp: January 26, 2025, 10:17:43 am
content: I ordered the "professional" version which has four different test voltages. I assume it's safe to use the 4V for for 3.3V components as well? It seems these come without any instructions but there seems to be few instructional videos in YT, but unfortunately in Spanish and Russian. Fortunately English captions were available so that's pretty clear how it works.But none of the videos were describing how to use the user: timeandfrequency mentioned pulse output (I think the lower right hand corner blue button in the picture). Can anyone decribe how that is used to test components?

author: RAPo
author_rank: Super Contributor
timestamp: January 30, 2025, 03:58:59 pm
content: The blue connection and buttons are for testing two components at the same time.First, set the parameters for one component, hooked up to red and connector black this is the reference componentNext, pick the component you want to test and connect it to the blue connector and the black connector just next to it.Then press the A/B button.This multiplexes the reading from the red and blue connection.The right blue button regulates the speed of the multiplex.Look at thisto see the switching in progress.Quote from: Veketti on January 26, 2025, 10:17:43 am

author: RAPo
author_rank: Super Contributor
timestamp: January 30, 2025, 04:11:51 pm
content: Yes really (my device just came in an hour ago) and yes a very serious drawback., 16V should be there.Quote from: timeandfrequency on January 25, 2025, 06:07:00 pm

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: January 30, 2025, 08:42:14 pm
content: Quote from: RAPo on January 30, 2025, 04:11:51 pmAt least, the description matches with what you get

author: Poroit
author_rank: Frequent Contributor
timestamp: January 31, 2025, 07:34:57 am
content: This one came up on the Repair Forum...."What More Can I do"

author: watchmaker
author_rank: Unknown
timestamp: January 31, 2025, 10:49:23 am
content: Quote from: kripton2035 on January 25, 2025, 10:43:13 amCouple $30 multi voltage tracer to the SC02https://www.aliexpress.us/item/3256805833382411.htmand you have a decent workable low cost unit.I have used the SC02 for a Thaikit w/Octopus but am relying on others about the V/I tracer itself.

author: RAPo
author_rank: Super Contributor
timestamp: February 01, 2025, 02:15:53 pm
content: Well, maybe we should start tinkering.The device has two 4.0V batteries.And a LD1117AG voltage dropper.If we can replace these to higher values there is some hope.I was looking for the pins that send the signal to the display, in the hope of tapering them off to BNC so we can also look at it on a (analogue) scope.Didn't find them, need some more time....Quote from: timeandfrequency on January 30, 2025, 08:42:14 pm

author: RAPo
author_rank: Super Contributor
timestamp: February 01, 2025, 04:04:57 pm
content: Added to my own post:A video using exactly this device in A/B mode is.Quote from: RAPo on January 30, 2025, 03:58:59 pm

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: February 01, 2025, 04:10:36 pm
content: Quote from: RAPo on February 01, 2025, 02:15:53 pmSure that it's worth improving this TE.If you can raise the AC test voltage the TE provides at its outputs, you will also have to add some attenuation on the X axis channel of the display.For these 'octopus' devices, the trace on the X axis (voltage axis) should always have the same width (which is close to the full screen width, or as wide as the graticule, if displayed). Of course, this is only true when there's no DUT connected to the output(s).If there's enough room, try to add a DPDT switch, so you can select between two ranges : one circuit will change the feedback resistor of the LD1117AG. The second circuit inserts an attenuator (= basic resistive divider) in the X channel measurement path.Update #1If the batteries (Li-ion I assume) are close to empty, you will have just a bit more than 5 VDC in the 2S configuration.I don't know if an in deep circuit analysis is feasible but as ultimate goal, it would be interesting to be able to separate the power supply of the sine generator (so that measurement voltage can be raised to 10 VACpeak or perhaps even 20 VACpeak by using asmall booster) from the supply of the processing assembly (probably 3,3 VDC).10 VACpeak (= 20 VACpp) sine waveform output is doable if the TL084 opamps are supplied with at least ± 15VDC (± 18VDC max).For 20 VACpeak (= 40 VACpp) output, an additionalhigh voltage opampis required. The low values series resistors must also be replaced by parts with higher power dissipation.*Update #2We started a deeper analysis of the TE circuit below,so several sentences in this post are no longer valid:- LD1117AG is a fixed value regulator : it's output voltage cannot be changed as easily as indicated here.- Presumably, there's a boost regulator after the Li-Ion batteries. So even close to empty, there should be enough voltage for the downstream circuits.

author: RAPo
author_rank: Super Contributor
timestamp: February 01, 2025, 04:48:59 pm
content: well, right now, the circuit is not working: pressing+keeping the on-button shows the LCD screen monetarily but with an off-scale low (in the sense of no green bars) bat. indicator. The battery themselves are full. I must have done something wrong/

author: Veketti
author_rank: Regular Contributor
timestamp: February 02, 2025, 09:22:04 am
content: Quote from: RAPo on January 30, 2025, 03:58:59 pmYes, I knew the A/B button but I meant this square wave button:

author: Kean
author_rank: Unknown
timestamp: February 02, 2025, 09:54:25 am
content: Quote from: Veketti on February 02, 2025, 09:22:04 amThe model RAPo bought was the one with the display which doesn't have that button.It seems the label on the button translates as "pulse". I suspect it changes the frequency at which it alternates between A & B measurements, which is what RAPo said.Quote from: RAPo on January 30, 2025, 03:58:59 pm

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: February 02, 2025, 10:52:11 am
content: Quote from: RAPo on February 01, 2025, 04:48:59 pmBummer, that's bad news.Lets make some checks on the internal power supplies.Remark #1: As I don't know your level of knowledge in electronics, here are some guidelines. But if you're experienced, you might find the below advices as unecessary or overkill.Remark #2: If you want to start a repair action, consider creating a dedicated thread in the 'Repair' section of this forum.At first glance, as I see no transformer on the PCB, I would say that all of the supplies should have the same GND.But it seems also that each battery has its own set of wires.So how does the PCB connect them together ? In // ? In series ? Or are they independant of each other ?I guess there are 4 regulators, but I can't read their markings :- a) theLD1117AGyou already mentionned; confirm the '50' voltage code (meaning 5 VDC output)- b) Just above the latter, the the part in theSOT223-4 packageis likely also a linear regulator- c) Towards the bottom, there's a SO8 part just above the '330' (33µH) inductor- d) Top right, there's another regulator/charger near the '2R2' (2,2µH) inductorIdentify each part, find their datasheets and check their output voltage.

author: RAPo
author_rank: Super Contributor
timestamp: February 02, 2025, 01:36:59 pm
content: I have some experience,The batteries come in with separate wires, but the - and + are connected.No universal ground from the usb-c connection.The LD117AG is a 50A81SMT2, the regulator above it is a 117m3,the SO8 near the 330uH is a an isolated DC/DCxl sem1 xl6007e1converter.I don't see a regulator near the 2R2.After some measuring, I think the indicated transistor is gone as a result of my looking around.Quote from: timeandfrequency on February 02, 2025, 10:52:11 am

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: February 02, 2025, 02:44:38 pm
content: Quote from: RAPo on February 02, 2025, 01:36:59 pmIndeed, it is not a regulator, it is actually a battery charger. Before knowing the chip's reference, guessing its' true functionality is only approximative.Top right there's the USB connector.Below, the 2R2 inductorThe square chip is a battery charger device :IP2326for a 2S Li-ion battery configuration.Quote from: RAPo on February 02, 2025, 01:36:59 pmInteresting to notice that there's an isolated DC/DC : this would mean that there are multiple GNDs on the board.On the datasheet of thexl sem1 xl6007e1, I only see application schematics where primary and secondary side have a common ground : there's no isolation. Even when a flyback transfomer is used in the 'SEPIC + inverting' mode. However, the circuit around the L1C winding in figure 7 could be modified to gain a truly isolated output.Could you figure out that the way the xl6007e1 is used in the 'NI-210SC' TE provides an isolated secondary side ?

author: Veketti
author_rank: Regular Contributor
timestamp: February 11, 2025, 03:56:12 pm
content: Finally got my NI-210G V-I Curve tracker. Few questions raised.1. with 4V and leads shorted the line is not perfectly vertical. Eg. compared to the 0.6V which is perfectly vertical. Other voltages are also straight vertical. Maybe this doesn't matter too much (please see first two pictures)?2. Measured transistors from defective BT speaker. One of the transistors gave bit weird trace like two different lines. Is this definition of faulty transistor or maybe something else (see the last picture)?Thank you

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: February 11, 2025, 05:00:09 pm
content: Hello Veketti,1. with 4V and leads shorted the line is not perfectly vertical.A not vertical trace means resistance : so for the range thats shows this behaviour, the probe/test leads resistance is not well compensated. Maybe there's a trimmer resistor inside thats needs some fiddling...2. One of the transistors gave bit weird trace like two different lineSeparated traces often means capacitante or TE output circuit is oscillating.Not realy relevant to declare the transitior as defective : it depends also on the junction your are actually measuring...What surprises me more is that the dual trace part is one division below the zero line, which means 'constant current' : and that's weird. Don't know if this is an artefact from the TE or if it has to do with the instrumented transistor. In the latter case, this could provide a slight evidence of defect.

author: Veketti
author_rank: Regular Contributor
timestamp: February 11, 2025, 05:55:53 pm
content: Ah, indeed capacitance. There was capacitor on that particular transistor base which showed those separated lines.Should the scope be in AC or DC coupling when using this? With AC coupling it drops one division below zero line.Edit: More info addedNo trimpots on the pcb to adjust the 4V compensation. However I noticed under microscope that the legs of the 16 pin IC on the bottom right side of the presumably MCU were badly soldered, so I resoldered them and tested it and the 4V looks pretty darn good to me now.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: February 11, 2025, 08:49:01 pm
content: Hello Veketti,So it was just an artefact that came from the setting of the oscilloscopeI would suggest you always select DC coupling.Because what I saw (in AC mode) was a constant negative current (while the voltage was varying) : onlyconstant current diodesshow up such a particular behaviour.Quote from: Veketti on February 11, 2025, 05:55:53 pmWow ! Kudos, you just fixed it, because the slanted trace meant the TE was defective on delivery.

author: Veketti
author_rank: Regular Contributor
timestamp: February 12, 2025, 07:12:20 pm
content: If I may continue little still, now that I've been playing around with it more. It seems that with the highest frequency 2kHz there is line separation even when the leads are disconnected. Does it mean that there are internal capacitance and whether it's normal to behave like this (see attached picture)? Would this be caused by bad design, inferior/bad components or something else?In which case you'd need this high frequency that lower frequencies wouldn't work?Too bad that the scope don't support ref when in XY mode. Is it normal for DSO's not supporting Ref in XY mode? Would be awesome on pcb to probe known good component and then press ref to get the waveform on display and then probe all similar components to see whether they match. Well there's the A/B function in curve tracer, but it's bit cumbersome as you run out of hands.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: February 13, 2025, 10:56:55 am
content: Hello Veketti,Quote from: Veketti on February 12, 2025, 07:12:20 pmThat's common on V/I trackers: at higher frequencies, the internal stray capacitances separate the trace. This is not to be considered as an issue.Higher frequencies are mainly used to test capacitors and inductances that display an elliptic trace.For these parts the possible values span over 9 to 12 orders of magnitude.So in order to see a nice ellipse (and not a flat one), you need to select an adequate frequency.Quote from: Veketti on February 12, 2025, 07:12:20 pmIt probably depends on the scope model, but I guess that the reference trace feature is not that common when using XY mode.On V/I trackers, the A/B function is dedicated to parts comparison.If you're short on hands^^, upgrade the provided probe set with someKlepsorminiature crocodile clips.

author: ME
author_rank: Frequent Contributor
timestamp: February 18, 2025, 02:26:48 am
content: why is the scan so poor the result is tiny and unusable?.

author: Veketti
author_rank: Regular Contributor
timestamp: February 21, 2025, 07:22:03 am
content: Quote from: ME on February 18, 2025, 02:26:48 amYou mean bad resolution? Well Siglent SDS800X HD -series don't really shine when it comes to XY mode. Or in other words, should I say that any analog scope beats DSO's in XY modeThis is partly the reason why I resurrected old Tek CRT scope..edit: Only disadvantage is taking a screenshot is bit more hmm old school.

author: ME
author_rank: Frequent Contributor
timestamp: February 21, 2025, 11:30:01 am
content: Just be aware, I brought one of those with the 24v wall wart, It sends dc only to the dut not like a tracker,it means having to reverse the probes, I got the one with the perspex cover cheap option.

author: Veketti
author_rank: Regular Contributor
timestamp: February 21, 2025, 04:10:35 pm
content: Interesting. Mine was supplied with 5VDC 4A wall wart. So it must step up the voltage. It would have been easier to step-down the voltage, so I wonder why it was designed to be supplied with 5V instead of 24V?

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: February 21, 2025, 09:56:37 pm
content: Quote from: Veketti on February 21, 2025, 07:22:03 amThat's exactely what I said earlier in this thread to@Smokey.But, I got noanswer to my last questionQuote from: ME on February 21, 2025, 11:30:01 amSeriously ?@Veketti's unit has only one voltage range, which is pretty dispointing and the version you bought only outputs DC ?What a scam !When I look at@Veketti's last (analog) screenshot on the TEK 2445, I'm quite sure that the output is AC.Quote from: Veketti on February 21, 2025, 04:10:35 pmProbably that 5V wall warts are easier to procure and cheaper, beacause it's the USB standard voltage.

author: Smokey
author_rank: Super Contributor
timestamp: February 22, 2025, 06:35:09 am
content: Quote from: timeandfrequency on February 21, 2025, 09:56:37 pmsure.. a crt can display real time persistence in a way that an LCD can't (natively), which is why you digitize everything at a high bandwidth and then take your time and display it on whatever method/medium you want. Hell, a high resolution digitizer using an etch-a-sketch as a display could be better than a CRT these days.(sorry, I had to reply.. I think that's the first time anyone has @ mentioned me and I got a notification)

author: Veketti
author_rank: Regular Contributor
timestamp: February 22, 2025, 07:08:54 am
content: Quote from: timeandfrequency on February 21, 2025, 09:56:37 pmI think you confused to member Rapo's display unit which has only one voltage range? Mine has 0.6V, 4V, 8V and 16Vedit: Attached the no load curves of all the voltage ranges at 400Hz. 0.6V seem to be all over the place. Scope can't trigger to it for some reason, but at least on this freezed frame the frequency matches. I removed the ground lead from the scope probe to minimize interference. I don't know what's going on.

author: RAPo
author_rank: Super Contributor
timestamp: February 22, 2025, 11:48:54 am
content: Well, mine is really kaputt. I don't buy a new one have the old Hameg component tester and a real curver tracer that must be enough.But when mine was working, it was a solid 4V.Quote from: Veketti on February 22, 2025, 07:08:54 am

author: Veketti
author_rank: Regular Contributor
timestamp: March 01, 2025, 07:03:13 pm
content: Does anyone know why some (ceramic) capacitors measured in circuit show dead short, but when measured by multimeter they're not short but instead have few hundred ohms of resistance? I quess this doesn't necessarily mean they're bad? Some same value capacitors does show as circle like capacitor should.

author: Grandchuck
author_rank: Super Contributor
timestamp: March 01, 2025, 07:49:45 pm
content: A shunt path is the likely reason.