This circuit was found in an Elektor from the 90s. Next to the circuit we have a table with the delays obtained when the circuit is connected according to the positions of the selector switches.
We find in a Radio Electronics of the 90s this low noise amplifier that makes use of an uncommon...
This circuit for controlling high power in the AC network was found in a Motorola documentation from 1968....
This circuit from a 1978 American publication is used on vintage vehicles that still have contact...