This astable multivibrator has an active cycle of 30,000: 1. We found it in a 1970 EEE. The components used are from that time.
This timer circuit uses a unijunction programmable transistor. The time is given by the capacitor and...
This circuit identifies the holes in a card with 8 bits of definition and was found in a 1995...
This simple circuit with LDR was found in the Radio Electronics magazine of July 1992. Any...