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Thread: 7805 regulator heatsink

  1. #1
    voldemort
    Guest

    Default 7805 regulator heatsink

    Hi,
    I am building a highly compact bot. I have a 9V source, and I am driving a microcontroller with the help of ua7805 regulator. The controller drives two stepper motors (9V source) through two ULN2003s. My question is how essential is it to solder the regulator along with the heat sink? (As excluding it will really help me maintaining its compactness)

  2. #2
    voldemort
    Guest

    Default

    missed one tiny detail, the 9v source is a 9v battery.. is that feasible for the above load??

  3. #3
    Senior Member Cyborg
    Join Date
    Sep 2004
    Posts
    162

    Default

    Since your 7805 shall drive only the microcontroller the current drawn would be very less and it wont heat up.
    and since the source voltage is also 9v, (drop is only 4V)
    Hence there is no need of heatsink in this case.

  4. #4
    Guest

    Default

    hi this is pallav(pallav_engg@yahoo.com)

    you can avoid heat sink if the current output taken from the regulator is less than 100mA

    if load is more than that ,than inspite of using a external heatsink (like aluminium,etc) use a PCB integrated heat sink. On the pcb provide lagest(possible) copper area an connect it to the regulator tab.

    hope this will help you.

  5. #5
    Senior Member T-1000
    Join Date
    Jun 2005
    Location
    bangalore
    Posts
    325

    Default

    experts suggest to solder it in tat way....
    it is really needed..
    steppers draws a lot of current and u need to cool the regulator if u want it to work fine... else it might blow up{has happened with me}...

    so do use a heat sink..
    if u thought u r the only mad person on the planet.......u got serious competition here

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