This TTL shield with high level logic is from the LM111's own 80's manual. The integrated circuit is no longer easily found, but the circuit can be adapted to use modern equivalent operational amplifiers.
Incandescent lamps and heaters can be controlled by a low power switch using this circuit. The...
August 2016 - It can be found at Mouser Electronics the new sensors light to digital OPT3002 from...
This alarm uses several sensors that directly trigger a sensitive relay. A larger relay can be...