4093 NAND & IRF510 Pulldown resistor???

Discussion in 'The Projects Forum' started by electronice123, Jul 15, 2010.

  1. electronice123

    Thread Starter Active Member

    Oct 10, 2008
    I am trying to build a simple pulsing circuit.

    I am using a 4093 NAND logic to pulse a IRF510 FET. The NAND has an input v of 12V, output will be about 12 as well.

    The threshold for the IRF510 gate is 2-4V.

    I have read about pulldown resistors, but don't quite understand them???

    Is a pulldown resistor what I need to bring the voltage to threshold voltage range of 2-4V?

    How do you determine the resistance needed to do so, or do I need a voltage divider?

    Or do I even need to worry about it since the IRF510 Vgs max is 20V?

    My other question is how do I determine the resistor needed between the 4093 NAND output and the IRF510 Gate???
    Last edited: Jul 15, 2010
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    The threshold voltage is a point at which the FET just starts to conduct. You want to raise the gate voltage right up to 12 volts to turn it on. The faster, the better. You should place a small resistor in series with the gate to suppress oscillations - about 100 ohms is good.
  3. electronice123

    Thread Starter Active Member

    Oct 10, 2008
    OK.....Thank you beenthere...Your knowledge has helped many.
    I appreciated it very much!