Identifying TO-220 Components

Discussion in 'General Electronics Chat' started by Qwazzerman, May 10, 2012.

  1. Qwazzerman

    Thread Starter New Member

    May 8, 2012
    My grandfather tinkered with electronics decades ago and I've recently Most of the parts are easy to identify. However, there are a little more than a dozen components that have me stumped. They're all in TO220 cases and only two have any kind of writing on them.
    I'd ask my grandfather but unfortunately his mind isn't what it used to be...
    I've got a multimeter with a transistor tester on it and I've positively identified (I hope) 4 bipolar junction transistors (by the fact that they only give a Bfe reading with one pin arrangement, no reading with two, and infinite with the final arrangement).
    I've attached a picture. The four in the top right corner are the bipolar transistors. Also, the second from the left (IT48), according to the internet, is supposed to be a TRIAC, assuming that H3775 is the date code meaning 37th week of 1975.

    The pins also vary slightly, as you can see by the picture.

    So my question: Is it possible to figure out what the rest of these things are with a multimeter (or two)?
    Also: do the drill marks signify anything?

  2. Bernard


    Aug 7, 2008
    I think it best to just throw them out as you would not pick one to use in a worthwhile project. Now if I could only use the suggestion for my own stach.
  3. takao21203

    AAC Fanatic!

    Apr 28, 2012
    You would need a good transistor tester,
    that actually puts the transistor in a circuit where it must work as an amplifier.

    And where you can switch the pins, instead of swapping wires, to identify configuration.

    I have not yet build such a thing for MOSFET.

    They could be anything, transistor = common, MOSFET, or TRIAC, Thyristor.

    Diodes you can identify with low pass voltages, 0.2V, high power types also use TO220. Usually double diodes if they have two pins.

    See attach for a transistor tester...
    Qwazzerman likes this.