This servo circuit was found in 1969 Motorola documentation. Integrated circuits and transistors are types of the time, hard to find today.
This circuit was found in a 1970 IEEE publication. The circuit functions as a voltage controlled...
Found in a documentation from the 90s, this circuit limits and amplifies a voice signal in the 800...
This gas sensor circuit was found in July 1976 Radio Electronics magazine. The TGS sensor was a...