transistor

Discussion in 'General Electronics Chat' started by joni, Nov 4, 2009.

  1. joni

    Thread Starter Member

    Oct 4, 2009
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    transistor
     
    Last edited: Nov 13, 2009
  2. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
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    The collector is connected to the case of the part.

    Here is a data sheet for the part from ONsemi. If you look on the very last page, in small print under the table, it shows the connections.

    pin 1 base
    pin 2 emitter
    case collector

    http://www.onsemi.com/pub_link/Collateral/2N3055-D.PDF

    It certainly doesn't jump out at you...
     
  3. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
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    I looked again at the data sheet in the link you provided and the pinout is on the front page, inside the box with the part dimensions. It did not immediately jump out to me at first, which is why I looked at ONsemi.
     
  4. joni

    Thread Starter Member

    Oct 4, 2009
    39
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    transistor
     
    Last edited: Nov 13, 2009
  5. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
    864
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    Here is a link to the AllAboutCircuits book about transistors.

    http://www.allaboutcircuits.com/vol_3/chpt_4/index.html

    The specific transistor(s) that you have picked works like any NPN or PNP transistor, depending on which one from the data sheet you intend to use. You have the two pins for the base and emitter. For the collector, you need to electrically connect the case of the part to the circuit. All three connections are present.

    Does that answer your question or do you have something more specific in mind?
     
  6. joni

    Thread Starter Member

    Oct 4, 2009
    39
    0
    transistor
     
    Last edited: Nov 13, 2009
  7. bertus

    Administrator

    Apr 5, 2008
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    2,346
    Hello,

    The collector is connected to the housing.

    [​IMG]

    Greetings,
    Bertus
     
  8. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
    864
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    The entire outer shell of the device is connected to the collector of the transistor.

    The mounting hardware, screw and nut and washers can be used to connect a wire from the outer casing to the rest of the circuitry. The two holes in the wings are for the mounting hardware.

    Or, if you are making a PCB, the part decal should have a pad that allows for the physical connection of the shell to the wiring on the board. Some conductive paste may be necessary as well...
     
  9. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    There are sockets for TO-3 devices available (the 2N3055 is in a TO-3 package). They make connections easier, but you will need to use an insulating pad to keep the collector from shorting to the mounting surface.

    2N3055's are famous for inefficiency, so they get hot. They almost have to be mounted on heat sinks.
     
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