This circuit was found in a 1968 General Electric manual. The circuit is for 3 A motors but can be changed according to the SCR used. The SCR is type 106 and R1 is 10k.
This circuit is from a Radio Electronics from October 1963. The LDR and transistors are from the...
This circuit was found in an American documentation from the 80's. The transistor is a...
This circuit, found in documentation from the 1980s, uses an operational amplifier from that time....