Found in 1980s Electronic Engineering, this circuit uses common phototransistors as sensors. The circuit is CMOS using an integrated 4011.
This circuit is asymmetric with the mark-space relationship determined by R1 and R2. The diode can be a...
This basic Schmitt trigger was found in an American publication from 1968. The circuit uses...
This circuit is from a 1967 publication and applies to incandescent lamps up to 600 W. Triacs must be...