This circuit for incandescent lamps was found in the February 1972 Radio Electronics magazine. The triac is rated according to the lamp power and the sensitivity adjustment is made in R1.
Found in an American publication on transistors from the 60's, this circuit uses a transistor...
This circuit is from a 1974 Ferranti transistor manual. Transistors are general-purpose types at...
This circuit for automotive use was found in 90s American documentation. It is possible to monitor...