This conventional relay light detector circuit uses a 741 as a voltage comparator. The sensitivity adjustment is made in R1. The supply voltage depends on the relay used.
This circuit was obtained in a 1986 documentation consisting of an active frequency divider for...
OSEPP makes available through Mouser Electronics a series of 100% Arduino compatible robotic kits. The...
We found this circuit in a 1977 National Semiconductor audio manual. The integrated circuit is the...