555 reley switch timer

Discussion in 'The Projects Forum' started by l2adiant, Apr 16, 2013.

  1. l2adiant

    Thread Starter New Member

    Apr 16, 2013
    hello guys! i want to make a circuit that can switch ON and OFF a relay 4 time with adjustable delay from 2 to 5 second

    when i close the circuit it should start the count from 1 to 4 (ON/OFF) and then stop after this, when i reset then again it should count 1 to 4 and stop

    can u please help me?
  2. Georacer


    Nov 25, 2009
  3. tracecom

    AAC Fanatic!

    Apr 16, 2010
    To be clear, do you want to switch one relay ON for X seconds (X adjustable from 2 to 5) and then OFF for X seconds and repeat this sequence four times? Or are there four separate relays?

    If the adjustable time won't be changed too often, you could use two 555 circuits. The first would be in the monostable mode and would be adjustable from 8 seconds to 20 seconds. The second would be in the astable mode and would be adjustable from 2 to 5 seconds. This would mean that the first would go high, and thus enable the second. The second would pulse continuously as long as it was enabled. So, whenever the time was changed, both circuits would have to be adjusted. Is that acceptable?
    Last edited: Apr 16, 2013
  4. Mussawar


    Oct 17, 2011
    Hi, You can use a 555 Timer along with CD4017 counter. Attatch the 5th output (Q5) of counter with Clock Inhibit (C.E) pin (Please see the datasheet of CD4017 for pin configration). It should work fine for you. I'm already using it with my automatic self start power generator. 555 output will go to pin 14 of od counter and when it'll start counting. Q0,Q1,Q2...Q5. At Q5 it'll inhibit the counter and itt' stop counting. That's what you need. You can also use counter's reset pin for for your need.