Found in a Popular Electronics from the 90s, this circuit can act as a transmitter for an audio link. The output transistor admits a higher power equivalent, depending on the LED.
The frequency of the signal produced by this oscillator depends on the amount of light falling...
The circuit presented is based on a mechanical tuning fork. The circuit is suggested by National...
This is a well-known RC oscillator configuration using a 741 operational amplifier. The circuit is from...