Mounting TO-204

Discussion in 'General Electronics Chat' started by Regected, Jun 10, 2009.

  1. Regected

    Thread Starter Active Member

    May 24, 2009
    30
    0
    What is the easiest way too mount and connect a TO-204 package? Is there a PCB/heat sink package on the market to make this simple? Also, could i just mount it to a heat sink with the pins sticking up, away from the heat sink?

    The device I'm trying to use is a 2n3055. The driving circuit is mounted on a buss board with wire leads for the 2n3055.

    Also, does anyone know the difference between the TO-204 package and the TO-3 package? I have parts from three difference manufacturers that appear to be physically the same, but are listed as different packages.
     
    Last edited: Jun 10, 2009
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Those used to be TO-3 packages. Try a Wakefield 680-125A or 641-A. The sinks have holes for the mounting screws plus the base and emitter leads. You can also find insulating pads so the heat sink isn't at case potential.
     
  3. Regected

    Thread Starter Active Member

    May 24, 2009
    30
    0
    So I just need to bite the bullet and solder my wires directly to the leads?
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Yes. The two leads are the base and emitter. The case is the collector.
     
  5. Regected

    Thread Starter Active Member

    May 24, 2009
    30
    0
    Thanks for the help. Think I'll just modify an old PII heat sink to fit all 3 transistors onto one location. Nothing to buy and would look cool.

    Any advice on the easiest way to solder to the leads?
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Not much magic involved - you wrap a bit of bare wire around the B - E leads and solder. It's nice to crimp a ring terminal to the collector wire and capture it under one of the mounting screws.
     
  7. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    You can get TO-3 sockets too, many of the old TV's had the PSU and H-out transistors on TO-3 sockets, likewise some old PSU's. I've got a nice little box of TO-3 mounting stuff here collected over 30 years.
     
Loading...