Found in an Electronics World of 1966 this circuit can be made with current power transistors. It causes colored lamps to flash to the rhythm of the audio signal applied to the input.
This conventional 4 channel circuit with the 4017 and 555 was found in the November 1991 Radio...
Found in documentation from the 1980s, this circuit makes use of discrete components of the time....
This circuit was found in a Popular Electronics of the 90s. The resistor R4 determines the load...