remote power on/off

Hey guys/ gals

I have installed a unit in my car that is on all the time. I would like to be able to turn it off and on, via a wireless remote control switch. Any ideas as to how i would begin to do this? i have the unit hooked up directly to my battery.

many thanks in advance

If the remote control unit has a positive voltage output, connect the red wire of your radio to that wire.  If it has a ground output you will neeed to use a relay as shown in the following diagram.

hello

Thanks for the quick response. However, i would like to keep this "unit/sensor" on all the time, but when i need to shut it off, i would like a wireless remote button to do this. Do you have any suggestions for a remote as well?

I think there's a 3 relay diagram on here (this site) that will do that. It's been nearly 15 years since I did pretty much the exact same thing for a different project. I'd have to draw it out but it only took 3 standard relays, one triggered, second stayed on and the last turned the second one off when the ignition was engaged.

How much current does the device pull?  How often do you need to turn it off?

You could go with a cheap keyless entry system or even a basic alarm system as long as it has an AUX output.  If you used the keyless system / alarm wouldn't matter, but it would give you a remote, a receiver, and a control channel to switch the load on and off.

The only thing that is hard to say is how to do the actual switching.  if you use a "standard" autmotive relay (like a Bosch) the current consuption will leave you with a dead battery.  If you can answer the questions above we may be able to find a solution.

I calculated about 58mA of current draw based on the info above.  You could use a 12vdc reed relay and a standard keyless entry system (with aux output) to do what you are trying to do.