Do I need a resistor for relay power supply hack?

[1UP]

I've been using my hacked power supply for some time now...It's basically a power strip that has a relay wired inbetween the 120v line in, and the strip's power switch.  The switching part of the relay is hooked to the 5v lead and ground on one of the PC's unused hard drive power connectors.  So when the PC is switched on, 5v flows to the relay switch, closing the circuit for the power strip and switching on the 120v supply.

My question is, do I need a resistor in there somewhere?  I've noticed some symptoms with PC crashing that suggest the power drain is too high.  I know that other components need current-limiting resitors to prevent current overload, but should I need anything to limit the PC voltage pulled by the relay?

[Brax]

I've heard that it's important to use the 12v lead on that same power connector to get the proper 5v. Or the proper amperage or something. Ok, I don't know all the particulars but it's worth a try.

[BobA]

You do not need to limit the current to the relay if it is a 5V relay.
 A diode should be put in the circuit across the relay coil.  This would be placed so that current will not flow from the 5V to ground but it would allow any spikes generated by the relay coil to be sent thru the diode and not sent back to your power supply. A 1n4007 would be a good choice.


                   Diode
     +5V -------|<--------  GND
                |           |
                 [Relay]
                    Coil

BobA