This circuit was found in a 1967 Japanese documentation. It consists of a touch control system with two transistors from the time. The circuit uses a power source and sensitive relays.
This circuit is from the 1990 Motorola Linear Databook. The integrated circuit used is the LF355,...
This high impedance amplifier is from 1985 documentation by General Electronic. The amplifier with...
Based on the TCA6600 or TCA5500 this circuit was found in a 90’s European documentation. The...