We found this circuit in a 1964 Electronic Design. It divides the frequency of a 20 MHz signal by 2. The circuit uses a transistor from that time. Details of the coils were not given.
This circuit generates interval signals controlled by a light sensor. The basic time of the sound...
This 1968 Mullard circuit detects fire by smoke using LDR-type sensors. The circuit makes use of...
With this circuit it is possible to generate 3-phase rectangular signals from a clock signal. The...