How to use TO-3 transistor

Discussion in 'General Electronics Chat' started by HaPPy_BoY, Jan 6, 2011.

  1. HaPPy_BoY

    Thread Starter Member

    Dec 5, 2010
    36
    0
    Hi guys, i have some 2n3055 transistor TO-3 package. It has only 2 pins; base and emitter. The "tab" is the collector. So let's say i want to use it in a circuit such as attached. How do i connect with the collector or is the tab grounded ?
     
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,766
    928
    They are usually mounted on a physically isolated heatsink inside the chassis. The heatsink will have voltage on it in reference to the chassis ground. The case of the transistor, as you guessed, is the missing connection.
     
  3. nomurphy

    AAC Fanatic!

    Aug 8, 2005
    567
    12
    Use a screw, nut, and wire on a ring lug to connect to the xstr case. An internal tooth lock washer is also useful for maintaining the connection between the ring lug and the case.
     
  4. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,000
    1,512
  5. HaPPy_BoY

    Thread Starter Member

    Dec 5, 2010
    36
    0
    I see . I just need to connect a wire to the case.

    So, just curious, if the collector is not connected, is it grounded by default ?
     
  6. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,766
    928
    if it is in contact with a grounded surface - it is.
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    If you get a socket for the T)-3 can and use an insulating washer, then the transistor can be placed on a grounded heat sink or case, but still have a voltage present on the collector. If that voltage is dangerous, then it is also possible (or was) to get a plastic insulating cover to protect users.
     
Loading...