Other versions exist on this site from various publications. This one is from the Radio Electronics Experimenter from 1990. The bargraph circuit uses the UAA170.
This amplifier for small cassette tape players was found in an English documentation from 1969. The...
This circuit is intended to trigger a TTL door or flip-flip from a signal coming from an SCR....
We find this circuit in a 1980s documentation. The circuit can be applied to modern operators with...