This circuit was found in a 1967 US publication. In it we have the implementation of a ring counter using only relays. Relay free contacts can trigger indicator lamps or LEDs.
Using an LDR, this Philips circuit directly activates a relay when light strikes the sensor. The...
This two-tone decoder has a bandwidth of 24%. The circuit is from a 1994 Electronics Now. The...
This series LED circuit was found in the February 1992 issue of Radio Electronics magazine. The...