I'm trying to integrate a key-fob type R/C, with an electric golf buggy. The key fob has six momentary "on" buttons that can activate six independent relays on the receiver side. Press a button and a relay is activated; release the button and the relay releases. Only one button at a time can be active.

My intention is to activate the drive motor on the buggy with a soft start and and a delayed off cycle of 5, 15, 30 seconds and E-stop, per respective key-fob button. The remaining two buttons would be used for steering activation. The motor is 12vdc, 30A, brushed.

Attached is a circuit I drew up after gleaning parts of it from different internet sources.

What I would like to know is if this an effective circuit setup? Perhaps there already exists a circuit that has solved this scenario. Any helpful comments would be appreciated.

 

Why don't you just take out the existing relays and use the MOSFET to switch without all those useless components. If you want to isolate then just try solid state relays instead.