This circuit is from a Radio Electronics from February 1959. The circuit has a speaker output and good sensitivity. Power is supplied from a 9 V battery.
This TTL trigger circuit with the 7400 can be used as a signal conditioner in an input shield for...
This circuit can be adjusted between 0.2 and 2 V to trigger with chosen voltages comparing them with...
With this circuit (shield) we can control a load from 500 mA to 1 A, depending on the transistor, using a...