This circuit was found in the February 1983 issue of Radio Electronics magazine. It is a 4-digit circuit with dedicated integrated circuits, with no power supply indicated.
We obtained this circuit from an old Argentine magazine. The circuit originally uses germanium...
We found this circuit in an old English publication. The sensor is a common LDR. and the...
This circuit is from an 80's component manual. The components are from the time, but the circuit...