This circuit was found in the October 1989 issue of Radio Electronics magazine. It drives an auxiliary relay with the call signal for a possible louder bell.
This circuit is suggested by General Electric in 1966 documentation. The Triac must match the...
This circuit was suggested by Popular Elecronics from the 90's. The circuit has high input...
This circuit is nothing more than a turn signal for two alternating LEDs that can decorate a robot...