Leftyretro
New Member
hi! I'm looking for a reverse polarity protection circuit diagram can any body help? it needs to be able to handle at leas 25 amps at 12 volts DC. any suggestions please.
Well I like the suggestion that JimB made a few posting back. Have the main power route through the normally open contacts of the relay to the circuit to be powered. Put a diode in series with one of the coil contacts. The relay will only close with correct polarity is applied and will then transfer the high current to the load through it's contacts. The relay can be mounted externally or if the equipment is large and important enough, the relay and it's coil diode can be mounted internally.
12vdc automotive relays can often be found at very reasonable prices as this example:
12V SPDT 30 AMP AUTOMOTIVE RELAY | AllElectronics.com
Lefty