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 obtained from an American technical manual from the 80's. The integrated circuit...
Found in a 1980s documentation, this amplifier features high common mode rejection. The operating...
This circuit is from a 1967 RCA documentation. Components can be replaced with modern equivalents. The...