This circuit with its light source was found in American documentation two years 70. Or transformer of the type found in small transistor radios of the time. The transistors are general-purpose.
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...