This is the power step of the previous circuit. Output transistors must be mounted on good heat sinks. The circuit is from documentation from the 60s.
This circuit appeared in the July 1969 issue of Radio Electronics magazine. The sensor is an LDR....
This circuit was found in an American 80's documentation. The transistor is of germanium of the...
This old 4-channel circuit was found in the December 1994 Electronics Now magazine. The circuit uses...