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looking for transistor

MatthewMatthew Posts: 200
edited 2005-03-07 15:42 in General Discussion
Hey. I'm looking for a transistor that can handle about 2 amps at 9v. Any suggestions?

Comments

  • upand_at_themupand_at_them Posts: 61
    edited 2005-02-28 01:13
    You're just switching a current?· Check out the transistors section of Glitchbuster (http://glitchbuster.com/#xstrs).· I'm using the IRL520N MOSFET to switch 1.5 amps, but it can handle up to 10A.· Depending on your demands you might need a heatsink.

    Mike
  • MatthewMatthew Posts: 200
    edited 2005-02-28 04:01
    Mike, thanks for the tip. What was your application?
  • upand_at_themupand_at_them Posts: 61
    edited 2005-02-28 22:57
    I use the IRL520N to switch current to a nichrome wire.· It's a weather balloon cutdown to jettison the balloon remains once it bursts.· With 1.5 amps the MOSFET doesn't even get hot, but I'm only using it·for the 10-15 seconds.· And the gate is logic level; you can hook it right up to a Stamp I/O pin.· The only other component I have on it is a 47K pulldown resistor, to keep it switched off when there's no input at the gate.

    Mike

    ·
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2005-02-28 23:05
    Matthew,

    Just out of curiosity, where are you getting a 9V supply of 2A? ....Sounds odd

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Beau Schwabe - Mask Designer III

    National Semiconductor Corporation
    (Communication Interface Division)
    500 Pinnacle Court, Suite 525
    Mail Stop GA1
    Norcross,GA 30071
  • CharlesCharles Posts: 3
    edited 2005-03-01 01:56
    How about the old standby pass transistor, 2n3055? It ought to handle that current quite well without a heat sink even.
  • MatthewMatthew Posts: 200
    edited 2005-03-01 05:53
    Mike, that sounds cool. I'm using it to ignite ematches for an ejection charge in a rocket! It should take less than half a second to burst.

    Beau, I'm getting the power from a Panasonic 9v N-6PT.
  • MatthewMatthew Posts: 200
    edited 2005-03-01 05:53
    Charles, I have noo idea. I'm just a newbe!
  • upand_at_themupand_at_them Posts: 61
    edited 2005-03-01 15:54
    If you're only switching on for a few seconds you can get away with the IRL520N without a heatsink.· Actually, any TO-220 case device is going to be able to handle the load.· The 2N3055 is a TO-3 case, which is a bit bigger, but it will still do the job.· The small plastic TO-92 case devices are only good for a couple hundred milliamps.· And the small metal can TO-18 devices are good up to about 800mA.

    Mike
  • Jonathan AllisonJonathan Allison Posts: 96
    edited 2005-03-01 16:56
    What about a TIP-120?

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    Johnny
  • MatthewMatthew Posts: 200
    edited 2005-03-07 03:00
    Mike, may you explain the schematics you used for that IRL520N MOSFET?

    Thanks,
    Matthew
  • upand_at_themupand_at_them Posts: 61
    edited 2005-03-07 03:09
    There's nothing to know about the IRL520.· Gate goes to the Stamp or PIC I/O pin, Drain to the current source that you want to control, and Source to ground.· And to keep the Gate from floating use a pulldown resistor, about 47K will do.

    Mike
  • KenMKenM Posts: 657
    edited 2005-03-07 03:24
    Is this what you are looking for?
    IRL520.JPG
    352 x 305 - 28K
  • MatthewMatthew Posts: 200
    edited 2005-03-07 04:19
    Okay! Thanks a bunch guys!
  • upand_at_themupand_at_them Posts: 61
    edited 2005-03-07 14:15
    Thanks for posting that schematic, Ken.· I don't have any drawing tools on my PC.· What did you use?

    Mike
  • KenMKenM Posts: 657
    edited 2005-03-07 15:42
    Free pcb layout software and schematic drawing can be found at www.expresspcb.com

    k
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