This battery-powered 3-valve circuit was found in American documentation from 1947; Two batteries are used, one high voltage and one low voltage for the filaments.
This circuit was found in a 1966 EEE. It is intended for automatic switching of the measurement range of...
This circuit was obtained from a Popular Electronics of the 90s. The SCR is of any type and the...
This is the basic receiver for the CIR12025 that consists of the transmitter. The circuit is...