This symmetrical four voltage source was found in a 1968 Motorola documentation. The circuit is of a type that was commonly used in that time amplifiers.
The frequency of this oscillator depends on the crystal used and has a threshold given by the...
This simple circuit does not use relays, directly activating an audio oscillator when the light...
This filter rejects 60 Hz signals and can be used as a hum filter in audio equipment, for example, at...