Found in an Electronics World of 1966, this circuit makes use of FETs of the time. Modern equivalents can be used. The high voltage supply suggests its use with tube amplifiers.
The circuit presented is based on a mechanical tuning fork. The circuit is suggested by National...
In this circuit of Texas Instruments an incandescent lamp is used as a light source, and lenses are...
One touch of the push button S1 and the circuit LEDs shown in the figure start to flash rapidly. The...