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 low impedance circuit was found in an Electronic Design from the 90's. Operational amplifiers admit...
This circuit makes use of an old operational one to generate clock signals that depend on the...
This basic version of the timer with the 555 was found in documentation from the 1980s. The relay...