This circuit is from the 80's but uses common components today. The relay is voltage sensitive according to the power supply used. Transistors may be general purpose types.
This circuit was found in Raytheon's 1967 documentation. The circuit uses an operating of the era,...
This small two-transistor amplifier was found in the April 1994 issue of Electronics Now magazine. This...
This circuit is from the 1990 Motorola Linear Databook. The circuit can be applied to other...