Switch a 12 VDC circuit from a 0.6 volt signal
Consider thisl note the output has only a WEAK drive ability.







simulate this circuit &ndash; Schematic created using CircuitLab

The circuit will provide almost rail-rail output, using the impulse
 coil, which I assume is just about a short (&lt; 100 ohms). 

Or you could use a comparator that accepts inputs as low as GND. Some older ICs with PNP inputs perform quite well.