Using a 106 series SCR, this circuit was found in the May 1971 Radio Electronics magazine. The quiescent current is very low and is given by the value of R1.
This circuit was found in a Popular Electronics from the 90s. The circuit uses a ceramic capsule as...
This circuit for link or alarm was found in the Encyclopedia of Electronic Circuits Volume 5 of...
This 15 W power stage was found in Radio Electronics magazine from August 1959. The transistors are the...