555 / LM371 / Mosfet.

Discussion in 'General Electronics Chat' started by cjdelphi, Apr 26, 2009.

  1. cjdelphi

    Thread Starter New Member

    Mar 26, 2009
    I came across a youtube video where he was using a 555 some mosfets and a voltage regulator, so I got wondering, If i used a Mosfet from the pin out on the 555 and fed that output into the Voltage Regulator (with a couple of caps to smooth it out)

    Could the 555 / Mosfet be used as a PWM on a LM317 to supply power to the application without the thing generating so much heat? could the LM317 handle the pulses (but i'm thinking the cap would fix that) and would this kind of setup be more efficient than using the LM317 (Voltage Source 12v - 15vdc) because once the LM317 supplies anything more than 500ma (at 12v) to say 3 - 4vdc you can seriously cook food with it would a PMW from a 555 to the Regulator make it more efficient and actually stay cooler for longer and use less power?
  2. bertus


    Apr 5, 2008

    Do you mean a kind of "pre-regulation"?
    Can you make a drawing of what you have in mind?

  3. mik3

    Senior Member

    Feb 4, 2008
    Better to switch the output of the LM317 rather its input.