This buzzer trigger can be used for small alarms. We find it in an 80’s American documentation. The supply can be done with voltages from 3 to 18 V.
This circuit is placed between the instrument pickup and the amplifier input. The same version can...
This circuit triggers on a lamp when the sensor (a metal plate us touched). Up to 100 W...
We obtained this circuit from a 1993 documentation. The circuit has current and voltage ranges that...