The main feature of this circuit found in an old American publication is that it is powered by the very signal it converts. The transistors are of the time and can be replaced by current types.
This circuit appears on the site in several variations depending on the source. This is from a...
This counter performs the same function as the 4020, but includes an internal oscillator. The...
Found in a 1968 Electronics World, this circuit uses operational amplifiers from that time. |...