Query about RELAY parameters.

Discussion in 'The Projects Forum' started by bishshoy007, Mar 12, 2012.

  1. bishshoy007

    Thread Starter New Member

    Mar 12, 2012
    I am trying to build a circuit that can automatically switch my computer on and off in a

    specific time interval. I am using relays that would be placed in between the mains supply

    and my computer setup. The programming part is over but I need suggestion buying the relay. I

    know it should have a voltage rating of 230V (AC), but what should be the current rating? How

    much peak current does a computer (including monitor, 5.1 speakers and 400W smps(i.e the

    CPU)) draws at maximum load. I just need a general idea. Please help !

    My Setup :

    20'' LCD = 40W max
    5.1 speakers = 78 W max
    SMPS = 400W (this drives the entire CPU)
  2. #12


    Nov 30, 2010
    I don't know what the instantaneous start up current of a switch mode power supply can be, but it's large. When I turn my 32" CRT television on, the lights dim for part of a second! I'd choose a relay sized for the power line circuit breaker, like 15 or 20 amps in the U.S.

    Your mention of 230 Volts tell me you aren't in the U.S. Go check the circuit breaker (or fuse) and get a relay that can handle that current.
    Last edited: Mar 12, 2012