The circuit shown is from the 1977 GE semiconductor manual. More modern equivalent SCRs can be used. R1 must be wire type.
This circuit was suggested by Texas Instruments in a 1980s documentation. The transistor must be...
This circuit was taken from a popular 90's Electronics. The LDR is mounted next to the LED to feed...
This circuit was obtained in an Argentine publication in 1976. It consists of a series voltage...