Replacement Components!

Discussion in 'General Electronics Chat' started by bytraper, Oct 30, 2010.

  1. bytraper

    Thread Starter Active Member

    Sep 28, 2010
    126
    4
    Hi Everyone,
    Ive got a speed controller on a customers 24v e-bike that uses SDP85N03L 83A 30V N-Channel Logic Level Enhancement Mode Field Effect Transistors.

    We want to use a 36v motor and the only parts in the simple controller blocking this are the Mosfets which are 30v max and the 7808 regulator.

    Can anyone suggest similar, but suitable higher voltage replacements for these two components ??

    Regards,
    Byt
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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  3. bytraper

    Thread Starter Active Member

    Sep 28, 2010
    126
    4
    Thanks Sarge,
    that mosfet looks absolutely perfect and has a faster switching time too, so less heat!

    I understand what you mean by the powering from the battery closest to earth, but the battery the customer bought is a sealed expox(?) filled 36v lithium ion battery, so thats not an option.

    Cheers!
    Byt
     
    Last edited: Oct 31, 2010
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    OK, so get a 7805 regulator, and connect it between the 7808 and the battery. Then connect the 7805's GND pin to ground via a 3.3k resistor. That should make the 7805 output about 22.5v, give or take a volt.

    You will also need an 0.33uF cap from the input of the 7805 to ground, and an 0.1uF cap from the output to ground.

    This way, the voltage differentials will be split between the two regulators.
     
    bytraper likes this.
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