good transistor tester in the <300$ range - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: September 26, 2024, 10:02:46 am
content: What is a good transistor tester in the <300$ range?Is there something nice like a DE-5000 quality device available?Mainly for repair testing for rarer transistors

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 26, 2024, 10:18:11 am
content: Instead of "transistor tester", search for "transistor curve tracer". There are a bunch of DIY methods out there, One of the simplest is use of a dual channel function generator and an oscilloscope. The siggen tenerates a stepped sawtooth and a triangle for each step of the first signal.But maybe you should start with defining better what parameters of the transistors (and for what types of transistors) you want to test. You can test quite a lot with a power supply, a breadboard, two DMM's and a few passives.On the top of the line you would have two SMU's, but that's not going to work out for your budget. And even with those you're still limited to pretty low frequency measurements. When you build the classical transistor amplifier with 4 resistors, you can test amplification on every frequency the rest of your equipment can manage.

author: watchmaker
author_rank: Unknown
timestamp: September 26, 2024, 10:49:20 am
content: Quote from: coppercone2 on September 26, 2024, 10:02:46 amFor ready to go with lots of documentation, not sure the Heathkit Curve Tracer can be beat for that price. $300 should buy one immediately, but if you wait you can get them for under $150 shipped in US. Virtually all the test parameters are adjustable.I did successfully(after much aggravation) build the ThaiKit, but final cost was about $125 and it only supplies up to 15 v. No good for power transistors. But curves match my HK. I even put a USB scope on the box and I do keep it on the bench for quick checks.

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 26, 2024, 10:57:55 am
content: You should have a look at the "Peak Atlas" devices:https://www.peakelec.co.uk/acatalog/dca55-atlas-dca-semiconductor-analyser.htmlThey´re still very affordable, but provide quite a lot of detail information about the tested transistors. It´s hard to not compare them to the ubiquitous Atmel-testers, but if you compare they deliver much more detail information and some even are capable of basic curve tracing - together with a computer.

author: iet
author_rank: Frequent Contributor
timestamp: September 26, 2024, 11:12:41 am
content: Quote from: coppercone2 on September 26, 2024, 10:02:46 amGive an example of such transistors.

author: coppercone2
author_rank: Super Contributor
timestamp: September 26, 2024, 09:08:29 pm
content: idk man like germanium and obsolete stuff? There is always something that comes up and it costs like $30 to buy a new one. I dont' remember my last project but with the 6177 current source it was starting to drive me crazylike a HP part # without a N equivalentThe Atlas looks interesting. Yeah I was thinking about a battery powered portable unit. The heathkit is a beast. That looks like what you need to really match some transistors. I just wanna detect if something is reallllly bad, because I had circuits so funky I figured every single part must be bad (the measured values were just totally bogus).

author: wobbly
author_rank: Regular Contributor
timestamp: September 27, 2024, 09:59:36 am
content: @Phil1977,+1 for the Peak products. I have a DCA55 myself and it's a great tool. The company has a reputation for excellent customer service too, here's a typical example:https://youtu.be/4dxwOpe0vE0?si=xNq_p-IRzXAmSDg3I didn't know they had an advanced one with a curve tracing feature! Must...resist... buying more...test equip-........ Transaction complete!

author: HarryDoPECC
author_rank: Regular Contributor
timestamp: September 27, 2024, 12:40:35 pm
content: I have wondered about this (no affiliation):https://electron.plus/collections/curve-tracerIt's PC-hosted so there is that hassle-factor but looks to do up to 100V at some amps, so quite capable for the price. I have a similar problem with vintage transistors, often unmarked or no data available, so curve tracing can be very helpful to try to define substitutes.Anybody got one/tried one??

author: iet
author_rank: Frequent Contributor
timestamp: September 27, 2024, 04:20:44 pm
content: Quote from: coppercone2 on September 26, 2024, 09:08:29 pmWith this simple device and DMM, you can check germanium transistors for leakage.http://www.geofex.com/article_folders/ffselect.htm

author: coppercone2
author_rank: Super Contributor
timestamp: September 27, 2024, 06:32:43 pm
content: I hate it so much I don't want to plug anything in other then the component, that needs multimeter hookup etc. I want a piece of test equipment not a project, its a pretty serious capability to have transistor measurement equipment that is well designed and purpose built

author: iet
author_rank: Frequent Contributor
timestamp: September 28, 2024, 07:57:51 am
content: Quote from: coppercone2 on September 27, 2024, 06:32:43 pmI understand you well. I am also interested in methods and devices for testing transistors. One of the unpleasant problems with transistors and diodes is leakage. It is more noticeable in germanium transistors than in silicon ones.Today I saw an answer about what device measures and takes into account leakage in germanium transistors. In my opinion, this is what you are interested in.Q. Is the DCA75 ok with germanium transistors, can it measure leakage current and does it take into account the leakage current for its gain measurement?A. Yes. The DCA75 will detect the germanium (or silicon) type of semiconductor. It will measure leakage current and it takes that leakage into account when measuring gain (unlike most multimeter hFE measurements).https://www.peakelec.co.uk/acatalog/dca75-dca-pro-semiconductor-analyser.html#SID=24

author: coppercone2
author_rank: Super Contributor
timestamp: September 28, 2024, 08:03:10 am
content: niceI have to replace 4 more transistors that are fried in 6177, test it, if it still does not work I get the testerThey were maybe working, but my hand slipped, 3 diode and 4 transistor got whacked, I damaged it a few months ago during my last attempt.I think the y all measured diode test OK before, but maybe if I replace them flat out now, because their broke, it might work

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 28, 2024, 12:46:21 pm
content: The main drawback of the Atlas seems to me that it only works well for small signal transistors. If you need larger current or voltage, you need something else.But for small germanium types it may be just right.

author: Gyro
author_rank: Super Contributor
timestamp: September 28, 2024, 12:51:57 pm
content: It is a shame that it can't squeeze out a little more power when it is being USB powered, rather than when it is running on the internal AAA cell. A bit of a missed opportunity (although I suspect that it is component limited).

author: iet
author_rank: Frequent Contributor
timestamp: September 28, 2024, 05:18:04 pm
content: I am looking at the Atlas 55. There is an opportunity to buy it cheaper, that is, one that has already been used. So far I do not really understand how it determines a leak, or rather, to what extent. And it seems that there is nothing to compare it with yet. Otherwise, everything is as usual - good/bad, etc.I found about the leakage current in the datasheet. This is good.https://www.peakelec.co.uk/downloads/dca55-datasheet-en.pdf

author: wobbly
author_rank: Regular Contributor
timestamp: October 01, 2024, 06:16:17 pm
content: MyPeak Atlas DCA75 Proarrived todayMy previous experience with their gear is limited to owning the DCA55 (for many years since I bought it from Maplin's probably 15 years ago!).The'55is a nice bit of kit and lasts a long time on a single 12V cell.The'75has all the capabilities of the '55 but also has improved analysis of Zener diodes and now supports 3-pin voltage regulators too!I tried a bunch of regulators from my parts bin and it did a good job with all of them. Even a VLDO (ST brand L4941 IC that I desoldered from a Cumana external 3.5" floppy drive circa 1988!). Managed to measure the drop-out voltage to be 0.1V at minimum current (about 4mA), compared with 0.2V in the datasheet for that component, IMHO that's pretty decent performance (I'm no expert though).Given an LM317 it correctly recognises the pinout and reports that the output voltage is 1.249V (which is pleasingly close to the IC's internal reference of 1.25V).The device is particularly verbose about Darlington transistors, such as a TIP125. The attachments show the device showing page 1 of the analysis of the TIP125 and then the following 3 pages which are accessed by scrolling using the right-hand button.Then there's the curve-tracing feature. This is pretty slick! The final attachment shows the same Darlington transistor's Ic/Vce curve. You'll notice that the analyser's stimulus voltage is limited to 12V. Given that it runs from a single AAA alkaline (Duracell branded) cell this is not too shabby.It does take a little while to generate the graphs ; which is fair given that it's a low-power battery driven unit. But it's rather pleasant that the Windows software draws the graphs on-screen in real-time as the unit streams the data out! Very nice feature. You can stop a trace if you want to re-adjust the settings and start over without waiting, that's really neat.When running from USB, the device takes it's power from USB and not the alkaline cell. And it does not auto-power off when on USB power. That's a nice feature. When not connected to USB the auto-off time is perhaps a minute or so, which is a good compromise.I'll be using this quite a bit in the coming weeks so I'll update my opinions accordingly.The hardware itself is good quality, decent materials etc. The software is good and quite flexible, with several ways to export the data.And the manual is very good also. The USB stick that comes with it has the Windows software on it. The manual has copious instructions to guide you around any issues that may arise. I didn't have any issues at all (Win10, latest).Bloody brilliant bit of kit! With limitations of course. But it's a tiny device which runs from a cheap battery and has some cool and quite exotic features.

author: nfmax
author_rank: Super Contributor
timestamp: October 01, 2024, 06:48:36 pm
content: My DCA75 also arrived today. I’ve had a quick play with it and I am impressed too! It recognised an OC28 I have had in the junk box since the early ‘70s, and some triacs, which I didn’t think it would. I haven’t tried the PC software yet, but if it is as good as the instrument firmware, it should work well. The test hooks are apparently designed to minimise the chance of shorting between transistor leads, which shows attention to detail. The case is nicely made, too.

author: wobbly
author_rank: Regular Contributor
timestamp: October 01, 2024, 07:00:00 pm
content: Yeah, they have really upgraded the capabilities a lot since the '55 unit. I feel a bit guilty now - what will I do with my trusty old DCA55? The '75 completely supersedes it in every way as far as I can tell.I think this DCA75 Pro will end up velcro'ed to the side of my PC tower - I think it's that useful!Another trace - this time from the venerable 2n3904...

author: Smokey
author_rank: Super Contributor
timestamp: October 01, 2024, 08:18:11 pm
content: It's a little slow and low resolution compared to a real solution, but you can pretty easily script a dual channel power supply (dp832) and get vi curves. It's limited by the 1ma resolution and command update rate, but it works for a lot of stuff, especially bigger power devices.

author: Gyro
author_rank: Super Contributor
timestamp: October 01, 2024, 08:32:48 pm
content: Quote from: nfmax on October 01, 2024, 06:48:36 pmThe cost of reversing the effects of physical abuse is pretty reasonable too...https://www.peakelec.co.uk/acatalog/dca75-accessories.html

author: coppercone2
author_rank: Super Contributor
timestamp: October 27, 2024, 02:35:25 am
content: i bought it im not going to be terrorized by zener diodes and small transistors anymorethey makina me a fuckin crazy

author: coppercone2
author_rank: Super Contributor
timestamp: October 27, 2024, 02:41:42 am
content: I thought about it.Ima desolder the diode, clean it up, get a fucking bread board, a power supply, a multimeter, then promptly drive my car into a lakeor hook it up a little tester

author: factory
author_rank: Super Contributor
timestamp: October 27, 2024, 06:02:33 pm
content: Quote from: coppercone2 on October 27, 2024, 02:35:25 amCan't be any worse than this one.Even has live heatsinks on the back.David

author: coppercone2
author_rank: Super Contributor
timestamp: October 27, 2024, 06:54:07 pm
content: that is like if you shrunk the everlook hotel down by a factor of thousands

author: coppercone2
author_rank: Super Contributor
timestamp: November 03, 2024, 12:13:28 am
content: ok it seems to beep and correctly identify transistors no matter how you hook it up

author: coppercone2
author_rank: Super Contributor
timestamp: November 03, 2024, 06:02:05 am
content: are the heat sinks on the back acutally live or do you mean the transistors body?The insulator is easy enough, but isolating a hot transistor is more difficult. I have little white covers from some old Digimatic or some thing calibrator. It had this shit, and the answer was little plastic covers over the transistors. I think they were a bit smaller then TO-3 though? (that unit had the switches like 'welded' to the PCB and when traces started delaminating i threw it out, and there was green shit growing through all the wires, and the chassis looked super burned up, I think batteries leaked on top of it a long time ago or something, I thought the PCB might be compromised).However, if you use those white covers, they can hide a broken solder lug. It had a solder lug that was bolted to transistor body with the white cover on top. The lug fractured, but it got pinned down under the white cover, so there was a broken circuit but it looked like the solder joint was intact! Odd to see a lug fracture like that too on the neck between the hole and the solder joint. I wonder if the cover had something to do with it, but its hard to imagine why pressing it with plastic would make it break there.The white cover should have a brass insert in them, embedded, so you just screw it on from the back and it insulates the whole transistor. It also might have a few little air holes for some reason.In any case, I would advise you to clamp the lug through the bolt on the back side with some spacers, instead of clamping it between the transistor and the cover, because while I can't explain WHY, I have a bad feeling the lugs don't like being clamped by that plastic. maybe it got too hot and moved around too much and stressed it some how.This looks similarhttps://www.newark.com/keystone/4632/power-transistor-cover/dp/97H7266https://www.cariatielettronica.eu/gb/other-series/5769-2-pezzi-cover-case-calotta-di-protezione-per-transistor-in-formato-to3.html

author: coppercone2
author_rank: Super Contributor
timestamp: November 03, 2024, 06:47:14 am
content: it identifies a NIR laser as a LED

author: factory
author_rank: Super Contributor
timestamp: November 03, 2024, 01:58:44 pm
content: Quote from: coppercone2 on November 03, 2024, 06:02:05 amYes those three heatsinks are live, along with the transistor cases, given that this is a 300V 100mA current source and those are the regulator transistors this is not good.They will get relocated back inside the PSU when I've sourced some ceramic TO-3 insulator, as some previous owner lost the boron nitride insulators. Probably need to rewire that part when I move them, as it's quite a mess.These are what I've found so far.https://www.ebay.com/itm/233510502749David

author: Gyro
author_rank: Super Contributor
timestamp: November 03, 2024, 02:30:00 pm
content: Quote from: coppercone2 on November 03, 2024, 06:47:14 amA laser diode is an LED until it reaches the 'LASEing' current threshold.

author: factory
author_rank: Super Contributor
timestamp: November 03, 2024, 03:54:23 pm
content: Quote from: Gyro on November 03, 2024, 02:30:00 pmIt can also identify stabistors as LEDs, for obvious reasons.David

author: David Hess
author_rank: Super Contributor
timestamp: November 03, 2024, 05:23:08 pm
content: Syscomp Electronic Design makes a 1 amp 30 volt USB curve tracer if you can figure out how to buy it:https://www.syscompdesign.com/product/ctr-201/

author: coppercone2
author_rank: Super Contributor
timestamp: November 03, 2024, 05:53:34 pm
content: Quote from: factory on November 03, 2024, 01:58:44 pmLol for some transsitor those ceramic heat sink are shenanigans. The boron nitride ones I had on the 6177A disintegrated. The ones on the 6181C #1 and 6181C #2 crumbled a few edges but they were mostly OK. So I was happy to reuse them.However, I did do all the repair stuff on the 6177A where the boron pad disintegrated and replaced it with alumina pad. It did not fit in the square hole. Alot of the alumina pads you can get are too big. I had to trim them with a diamond wheel dremel after marking them in the shop.I also previously run into problems where alumina insulators were too thick to fit in HP stuff, so I had to replace all the bolts, but in your case the bolts look like they should be thrown away. And in another case, they were too thick, and the part leads were bearly accessible. I forgot where that was. Its a problem when its PCB mount and not wire mount. But that happens when you replace mica with alumina.I think it might be possible to make a boron nitride pad, if you have a semiconductor silicon saw and some moneyhttps://www.amazon.com/Heloawei-Ceramic-Rods-Nitride-Diameter/dp/B0BWNLLQ7V?th=1I got really pissed, because its a nice material. I am sure you can get it cut at a higher end machine shop because its dimensionally simple. It might not be such a advanced operation as we think, as long as they regularly make similar stuff. But I have a feeling they usually use heat to make these, instead of machining them, but it might be a option.If you are not familiar with it, the boron nitride pad is actually ROUND, and they have a fiberglass 'cutout' that goes around it to match the transistor outline. So all you really need is the right shape BN round disk with 2 holes, and a custom PCB cut out. The BN is not the same shape as the alumina pad, which is all inclusiveI don't know why, but I suspect that someone did not lose it, it actually disintegrated. Mine turned into like 10 pieces as soon as I undid the screws. I thougth maybe they tighten it good in factory, and the aluminum casting has a memory / mind, and over the years it warp and smash the insulator. I heard some castings behave strangely.you might want to check out that heat sink with some dye to see if its flat too. so you don't break more pads

author: factory
author_rank: Super Contributor
timestamp: November 04, 2024, 08:49:03 pm
content: That explains a lot, I was wondering why the picture from the 6186C had PCB type material showing, the ceramic pad being round explains that. There is some flexible PCB mixed in there too, that is long gone on mine. The PCB on the other side is only found in the 6186C, it contains a bunch of Zeners.This is what this 6186B is like inside, the surface of the heatsink will need work, as there is some corrosion, it's a pity there is a hole that the wiring is going through, that shouldn't be there, it's more work of the 'phantom tape bomber' responsible for the other bodgery.According to fischerelektronik, these aluminium oxide insulators cut be laser cut, not sure normal machining would be a good idea, it's too easy to break.There is another grade on boron nitride that is much harder to break (grey color), used for the lathe tips at work, a 5mm cut will shatter them eventually.Those 12mm diameter tips are approx £300 each.No idea how much amazon are pricing the regular grade at, as the geo-blocking is active for the link you added.No one seems to make the round TO-3 pads. Originals were HP #0340-0411, boron nitride part #H-4001, made by Union Carbide Corp.https://www.fischerelektronik.de/fileadmin/fischertemplates/download/Katalog/heatsinks.pdfhttps://www.mouser.com/catalog/specsheets/Aavid_Board-Level-Heatsinks_Cat.pdfDavid

author: coppercone2
author_rank: Super Contributor
timestamp: November 04, 2024, 10:02:18 pm
content: Its hexagonal pressed BN right? not CBN? One is ALOT softer. They could think you mean CBN. If its CBN then you probobly need lasers... its going to work like complete shithttps://www.bn.saint-gobain.com/products/machinable-ceramics#I have seen the darker color BN pads in the shape of the Alumina pads I think, in more serious equipment (navyish)EH I think you can cut it with diamond if you have a big wheel and its cooled well. Its just a massive pain in the ass and probobly pretty expensive to cut compared to a laser. Those places are VOLUME. No one likes it when a $30 tool makes 1 cut. There are like 4 different types of diamonds. You can get fully sintered (solid diamond bearing material), plated, plated and layered or brazed. (and all that in CBN too) And they have single crystal diamond tools and polycrstaline diamond tools for lathes (the single crystal looks like a ring diamond, and those can be low quality yellowish or high quality clear). And there is probobly more options. Its a bitch to find these diamond cutters... alot of people don't know they exist. Best bet would be to find one of the better ones and show it to someone, because likely they are thinking "there is no way a 2 layer plated diamond can do this" (cheap ass tile saw type thing) but it might not be the case for a 5 layer plate or a diamond matrix/composite (engineering cutter for $100)The heat sink will cleanup some what if you ultrasonic it with alnox from experience. The area under the transistors is usually much better quality (fly cut maybe) then the back side. Usually its painted on the air heat exchange side. If its actually nice and you want to clean the rest, put some tape over that to protect it from the chemical action for the long duration cleaning, you can clean it for a short period of time without the tape at the end before washing.Maybe this bad boy, if you can get it in like 1/8 inchhttps://www.hisglassworks.com/6-inch-x-3-8-inch-100-grit-sintered-diamond-straight-edge-wheel.html10mm diamond depthMost people think of 'plated' diamond (microns) not milimeters.If you have the stomach to find it herehttps://ukam.com/diamond-cbn-wheels-with-smart-cut-technology/then you would need to lap it on diamonds.If their not perfectly uniform between cuts, who cares, just mill the PCB to make it a little thinner. transistor to transistor variation in heat spreader thickness is irrelevant, it won't do shit if its 0.01 inches spread between 4 transistors. The PCB is easy to adjust in thickness. They just need to be flat and close. It would probobly mean lapping.But honestly, lasers are getting common. Maybe its alot cheaper to not do it yourself.

author: coppercone2
author_rank: Super Contributor
timestamp: November 04, 2024, 10:19:41 pm
content: but the alumina are not hard to cut, I did them free hand with a dremel.YOu clamp it to the heat sink with some washers without the transistor, and just cut along the heat sink to make it fitI the first one break a little before I got a hang of it. But otherwise they cut nice and smooth, just had a little bit of a goofy appearance (I used a dremel brand diamond wheel)