I want a relay that will switch toggle on/off mains power of 240V AC Australian power. (I don't know the amps) The power that will decide whether or not to allow the mains power to flow will be 5v DC. I don't know the amps but it will be very small. It will be driven but the USB connection from a laptop.

 

It all depends on the current, and the type of load (resistive, inductive, high inrush) etc..

 

I think in this case, it would be wise to use a relay rated as the fuse or circuit breaker that feeds the circuit.

@chris64 , what specific information are you looking for? (how can we help?)

 

Digi-Key Part Number 2371-SR1-1220-N-ND ~$18.ooUS . .