Found in a 1970 EEE, this circuit uses general-purpose transistors of the time. Transistors support equivalents and the ramp time ranges from 0.1 seconds to a few seconds, depending on C1.
This is a circuit with a period component that consisted of a voltage reference. The circuit is...
This experimental circuit was found in a technical publication from 1976. The diode can be of...
Tone controls for audio applications can also be considered filters that must attenuate certain...