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Power NPN transistor N344AB

Discussion in 'Electronic Design' started by slampen, Jan 1, 2011.

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  1. slampen

    slampen Guest

    My Peugeot 406 heater blower control module ceased to work the other
    day, and its power transistor is open. Must be an NPN since it is
    supposed to PWM the blower motor to earth (-12V).

    When searching N344* I find a lot of references to 2N344n.. (2N3440,
    2N3442... etc) but not this the exact version.

    I've uploaded an image of the 'fat' case here:

    Any suggestions to an equivalent for this..?

    Thanks and Happy New Year to all :)

  2. slampen

    slampen Guest

    Den 01.01.2011 12:45, skrev Greegor:

    This ought to be a high power NPN transistor. The heater blower motor
    is a powerful fan fused with a dedicated 40A fuse, so I suspect the
    current flowing through the transistor is at least 30A at full speed.

    The collector is connected to the fan and the emitter is connected to
    ground. When I short-circuit collector and emitter the blower runs at
    full speed.

    Can it be some kind of OEM type number?

    regards Geir
  3. TTman

    TTman Guest

    Try BUW48.....
  4. slampen

    slampen Guest

    Den 01.01.2011 13:17, skrev TTman:

    Fact or (wild) guess?

    I don't want to put in something which will be fried or might fry the
    CAN bus circuitry....

  5. TTman

    TTman Guest

    can't see that you need anything special.... this one is rated at 40
    amps.... there must be plenty more out there.
  6. Jamie

    Jamie Guest

  7. Jamie

    Jamie Guest


  8. Jon Kirwan

    Jon Kirwan Guest

    Nice catch! Shorting C and E by the OP to run the fan would
    actually be shorting D and S. I think the OP needs to look
    more at the base/gate drive part of the circuit, now.

  9. Jon Kirwan

    Jon Kirwan Guest

    .... assuming it was a TO-220/TO-247 style package.

    Did the OP say?

  10. Jon Kirwan

    Jon Kirwan Guest

    Never mind. I just looked at the posted image.

  11. Do you even READ a thread EVER... at all? You stupid ****?

    He showed us the failed part diagnostic, which proved the proper
    function of the "blower motor itself".

    Your lack of logic matches your incapacity to make "assessments" in any
    other realm as well. A root cause, in fact.

    You still need to receive yours, obviously. *THWACK!*
    Direct Hit firing solution resolved!

    Oh, darn! Usenet has no "Fire for effect" mode, or you would be
    vaporized by the laser from the "Real Genius" film! Or at least whopped
    upside da haed with a baseball bat or ancient shillelagh.

    The darndest thing though... if device number two is used, the urge to
    continue beyond the first whoppin' is irresistible!

    You're a brainless wonder. It would be fun to open up that skull
    cavity and prove it to be true.

    Ever see the first episode of "Lexx"?

  12. Jon Kirwan

    Jon Kirwan Guest

    The OP did write, "When I short-circuit collector and emitter
    the blower runs at full speed." Which, given Jamie's earlier
    comments and your additional post, looks like an N-FET and
    not an NPN, where the OP was shoring D to S, not C to E.

  13. Jon Kirwan

    Jon Kirwan Guest

    I hadn't even looked at your image, but Jamie had the wisdom
    to do that. I think Jamie has nailed it. If so, they are
    cheap and broadly in stock. This being the cheapest I could
    find quickly:

    To be absolutely sure before trying anything else, if you are
    still worried, you may need to take a measurement at pin 1
    and see what you observe regarding the driver when the system
    attempts to turn the fan on and off and post the information.
    Or else observe and comment what you see connected to pin 1.

    But it looks as though what you have is more likely an
    N-MOSFET. Particularly considering the discussion that
    Greegor uncovered.

  14. TTman

    TTman Guest

    If it's just a simple pwm, then NPN or N fet should work..... so long as
    there's a base resistor for NPN mode.
  15. slampen

    slampen Guest

    Den 02.01.2011 14:49, skrev Greegor:
    I thought that the whole thing is PWM regulated. Must be above 20kHz
    though becaus I have never heard an audible tone like with trains and
    other heavy electric motors...

  16. Jamie

    Jamie Guest

    It's the second number on the package.. which is a power fet and
    fits the app just fine..

    I've seen inverted numbers like this many times on packages.

  17. You asking that question makes it obvious that you should not even be
    anywhere near the electronics industry.
  18. slampen

    slampen Guest

  19. Jon Kirwan

    Jon Kirwan Guest

    I earlier posted a link to Future, where it is a dollar less
    I think.

    No accounting for shipping differences, though. And Digikey
    used to have a $25 minimum to skip another extra charge.
    Might still be policy.

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