This circuit is based on the light comparison of two LDR sensors. We found it in a 90s Popular Electronics. The transistor must be according to the indicator or load being driven.
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...