This circuit was found in a 90s Popular Electronics. The sensor can be any phototransistor.
This transmitter sends its signals to a MW radio over a distance of a few meters. The antenna must...
With each clock of the 555 (negative transition) the 4013 (flip-flop) changes state by activating the...
This inductively coupled oscillator was found in an American documentation from the 90's. The...
