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Transistor/Cap Tester — Parallax Forums

Transistor/Cap Tester

ercoerco Posts: 20,256
edited 2014-05-22 03:04 in General Discussion
My "Buy It Now" finger is itchy and twitching to order this nifty little meter which apparently can do anything and everything. My hope is that it might make sorting transistors from my junk drawer a bit less tedious. Has anyone tried these or shall I be the first guy in the pool? Got a better alternative?

http://www.ebay.com/itm/Small-12864-LCD-Transistor-Tester-Capacitance-ESR-Meter-Diode-Triode-MOS-LCR-NPN-/321397318526?pt=LH_DefaultDomain_0&hash=item4ad4c5e37e#ht_2803wt_2349

There are others half the price with fewer features and a smaller LCD: http://www.ebay.com/itm/Transistor-Tester-NPN-PNP-Mosfet-Thyristor-Diode-Resistor-Capacitance-meter-RC-/171260971226?pt=US_Measuring_Layout_Tools&hash=item27dff308da#ht_3532wt_958

Comments

  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-05-21 10:50
    Those are quite nifty and seem like they would be a bit easier than a volt meter that has the testers on them.
  • RDL2004RDL2004 Posts: 2,554
    edited 2014-05-21 10:56
    I bought one of the cheaper ones (1602 LCD and no zif socket) a couple of years ago. It's very useful, even measures ESR. There is a long thread about them somewhere on the EEVblog forum. Apparently the software was originally written by a couple of guys from Germany.

    edit: found the thread:

    http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/
  • ercoerco Posts: 20,256
    edited 2014-05-21 13:44
    I just found this video, even the cheaper one looks very capable.
  • TorTor Posts: 2,010
    edited 2014-05-22 03:04
    It's well worth reading the whole 30-page thread on eevblog.
    @erco: The large-display variants are, from what I can tell, not the best choice. They are not compatible with firmware upgrades from the original German authors (who continue to upgrade and improve the functionality). The cheapest ones are not the best option either, because they use smaller microcontrollers with less flash. The more expensive ones with simpler displays (like the one in your video), with the Atmega328 processor, is better because the later firmware variants focus on that one and it's more capable. A variant like this one seems to match what's needed:
    o Atmega328
    o It's even in a socketed DIP form factor and can be replaced
    o There's a crystal
    o I can't tell which regulator is used. If you read that long thread they recommend an extra 2.5V reference voltage if a simple 5V regulator is used (not needed if a more accurate 5V regulator is used).
    o I can't see if it's possible to add a socket for reprogramming, but as the uC is socketed it can be done off-board in any case. Reprogramming is something you would want to be able to do I think.
    There are other sellers of what appears to be the exact same board, some of them will pop up if you look up that ebay link.

    -Tor
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