We found this circuit in an Electronics Now from the 1990s. The circuit crashes when light strikes the sensor. Instead of the alarm a relay can be used to drive higher power devices.
This small-range MW transmitter can be used as a wireless microphone. The circuit is from an...
This single-transistor oscillator was found in Radio Electronics magazine from February 1962. The...
This source for common, non-high-power car radios can be used on the bench. It was found in a...