This small regulated power supply was found in a 1963 General Electric documentation. The special zener diode transistor can be replaced with an equivalent discrete configuration.
A touch or the simple approach of the sensor (metal plate) causes this circuit to emit a sound...
This damped oscillator generates percussion sounds played on a small amplifier. The circuit mimics...
This is an amplifier circuit from the 1960s using Sanyo's SK003 15W hybrid module. The hybrid...