555 monostable V/S lm339 voltage comparator monostable

Discussion in 'General Electronics Chat' started by devalvyas, Jul 5, 2009.

  1. devalvyas

    Thread Starter Active Member

    Nov 11, 2008
    I am using lm339 voltage comparators in monostable mode in one of my projects and am also using 555 in monostable mode.

    the output of lm339 comparator goes to NAND gate and output of NAND gate triggers 555 timer and the 555 timer in turn operates a Relay.

    Now i have 2 voltage comparator spare on my lm339 ic and i was wondering whether i can use the spare comparators and make a monostable in place of using a separate 555 ic....

    what is the difference between 555 monostable v/s lm339 monostable?

    i am attaching my current schematics below...
  2. kammenos

    Active Member

    Aug 3, 2008
    They are both connected as monostable with same time right? That would be the same with maybe difference in dc characteristics on the output. That would be irrelevant though as you drive a transistor.

    P.S. You have a mistake in your circuit. The transistor is misplaced.