This symmetric 30 mA x 15 V power supply was found in the Ferranti transistor manual from 1974. Transistors are common types at the time.
This circuit separates the bass from the treble in an audio signal. The circuit is from a Hands On...
This circuit was obtained in a 1986 documentation consisting of an active frequency divider for...
We found this circuit in a Popular Electronics from 1992. It consists of a voice scrambler used in...