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.
We found this circuit in a year 2000 documentation. It must be powered by a voltage of 5 V as it...
This circuit was found in the February 1990 issue of Radio Electronics magazine. The circuit uses...
Voltage comparators, such as those in the LM139/239/339 series, consist of devices that can be...