What are some good $20 transistor testers? - Page 1
Forum section: electronics / general

author: Evil Lurker
author_rank: Regular Contributor
timestamp: March 05, 2015, 08:32:51 pm
content: I found the thread last night about the $20 testers and skimmed a few pages of it. If I am thinking correctly they don't just do transistors, they do inductance and capacitance as well. I have seen a few of these things in action on places such as youtube and for the most part they seem fairly accurate, close enough for anything that I do. Can anyone recommend me a particular model from a seller?

author: JoeO
author_rank: Frequent Contributor
timestamp: March 05, 2015, 09:31:23 pm
content: Some are well constructed, some are not.You should be looking for one that has the ATmega328 in a DIP package and is in a socket.Also, the LCD display should be on standoffs that are screwed to the LCD display and the bottom board.I do not have one from this vendor but one like this:http://www.ebay.com/itm/Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter-MOS-PNP-NPN-R-C-L-M328-/200960094152?pt=LH_DefaultDomain_0&hash=item2eca27afc8

author: Evil Lurker
author_rank: Regular Contributor
timestamp: March 05, 2015, 09:53:57 pm
content: Quote from: JoeO on March 05, 2015, 09:31:23 pmThanks, that helps out a whole lot right there... I'm assuming the reason for having the Atmega as a discreet DIP package is to be able to upgrade/mod the firmware and/or replace it in case something happens to the tester correct? I like the idea of having a removable screen as well if I ever wanted to use it on my Arduino board.From what I have seen these things are some amazing devices for what they cost... I don't think I could even buy the individual components to build one for what a complete unit sells for.

author: JoeO
author_rank: Frequent Contributor
timestamp: March 06, 2015, 02:31:56 am
content: Quote from: Evil Lurker on March 05, 2015, 09:53:57 pmYes, by getting the unit with the DIP socketed 328, you can take it out and use another 328 to test new/improved code. Also, if you connect up a charged capacitor, you can blow out the 328.Don't over write the code for a working 328 until you have a new version running on a different 328.You are correct, you can't assemble one for the cost to buy one.

author: eas
author_rank: Frequent Contributor
timestamp: March 07, 2015, 10:05:02 pm
content: I bought three, different ones, and someday I may even post the comparison video I started.In the meantime though, my favorite isthis EZM Electronics Studio GM328. Its the graphical screen variant of the one JoeO linked to above. The firmware seems like a recent version of the open source firmwares with few if any customizations and most/all of the options enabled. As mentioned, it uses a socketed processor, for easy experimentation with different firmwares. I've purchased a few items from the seller and they have always shipped quickly and packed things well.I also tried a Fish8840 version (red PCB, transformer logo). No telling what version of the firmware it is using, but it is missing a number of features, and also has a design issue that wastes battery.The final version I tried was from 91Make with Efan modified firmware on a yellow PCB. I thought the graphical display had the best information design, but it also didn't enable some features of the original firmware.Both of these are mostly SMD components.

author: richfiles
author_rank: Regular Contributor
timestamp: April 24, 2016, 06:35:30 am
content: I know this is an old thread, but I didn't see any other threads not he topic, so why not.I was looking for one of these testers and came across a new version.http://www.ebay.com/itm/2016-EZM328-transistor-tester-ESR-table-frequency-meter-square-wave-genera-/172129915560So the big changes, is this one seems to have a footprint similar to the SMD version, but uses the DIP parts, with the LCD folding over the DIP components. It uses the revision V1.12K software, running on an M328 DIP chip. The LCD is socketed, and held by a pair of screws. It uses metal film resistors. There are two keyed header sockets. A three pin socket brings out test pins 1, 2, and 3 to a set of mini grabber style flying lead probes. I think the other header is for a the frequency generator. The test button is not a pushable rotary encoder, and I think it can be used to scroll through different modes rapidly. Still uses the same style ZIF socket, and is powered by a 9 volt battery. Price is higher than some of the other models, at $23 USD.Graphically, the software looks similar to the EZM model that was suggested last year.Anyone try one of these new model yet? I'm considering dropping some cash down on one. It's only about $5-8 more than the older models.

author: R005T3r
author_rank: Frequent Contributor
timestamp: April 24, 2016, 09:54:46 am
content: what about making one by yourself? Don't seem very complex...

author: richfiles
author_rank: Regular Contributor
timestamp: April 24, 2016, 06:54:22 pm
content: Actually, Search had failed me. I have NO idea why the megathread below did not even appear in my search!$20 lcr esr transistor checker projectThat is apparently the real thread where discussion of these devices is actively going on. Probably be wise to let this old thread be and move any new discussion over there! I only necroed this thread cause search results were a lie.Anyway, as for why not build it... Cause for $23 I can get all the parts, assembled, and on a proper PC board. I've only ever hand made etched PC boards, and as such, have zero knowledge or experience on CAD based PC board design. I doubt I could even buy the parts for what some of these sell for! $23 is simply the most efficient use of my time, for the best resulting product. I could go as little as around $13, but I'd rather get a model with a better interface and more options. I'd rather do the projects Iwantto build, rather than use what would definitely be far more than $23 in equivalent value for my time to make something I can easily buy. It's simply more efficient for me to buy it.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 24, 2016, 09:20:32 pm
content: If you want to follow along with the improvements on the tester, or add your own improvements the other thread is great. In other words if the tester is your hobby that thread and the advice presented here is spot on.If you are doing other things in electronics I would recommend one of the ones that comes already packaged in a case. You can check parts, sort your salvage gear, monitor changes over environment and all sorts of things without worrying about dropping a wire across a couple of pins or any of the other problems. In a couple years when the guys doing it for a hobby have developed some new feature you find appealing you go back on Ebay and spend another few dollars on the current version.I can't recommend a current vendor because mine is more than a year old and I don't remember where it came from, but for this kind of use there are a great many good choices.