Ensuring low amps on switch

I have a switch that i wish to install in my car.  I want to use it to drive a realy.  It says that 11MAmp is nominal and .5 amp is max.  If i hook one lead of my switch to the battery and the other to ground (with the relay in-line some where) how do i know i wont burn out my switch?  Do i need a half amp fuse?  Do i use ohms law? 14.4V/1050 = .0137142 - does this mean the switch sould only draw .01 amps?  Thanks for the help!

The switch does not draw down any current. The switch idealy should not have any resistance. It does however have a maximum current handling, which you have already noted.

The power source should always be fused within 18" of the source.

Regards

EVIL Teken . . .

Thx for the reply.  I have a 15amp fuse on the power supply.  What will determine the amps going across my switch?  Will the amps just be real low because the reisitance of the wire and switch are so low?  I am confused as to what factor determines the amps in a circuit.

I think you need to understand the basics first. Current is drawn down when a load is placed on the circuit(s).

So if what ever device consumes / draws down as a load will determine the actual current.


The reason you are using a relay and a switch is two fold. One, the relay will be doing 100% of the current tranfer.

So, depending upon the value of the relay which you select, whether it be 20, 30, 40 amperes. This is what dictates the maximum current the circuit can operate.

Obviously proper wiring length, diameter, and fusing all play a role.

The second reason for the relay is to isolate the user from high current. All the switch does is turn on-off the circuit.

Now you may very well buy a 20 ampere switch to do the exact same thing as a relay. But understand you will not have the benefit of a relay in isolating you and the circuit, also that high current source will be in the cabin with you.

I hope that helps.

Regards

EVIL Teken . . .