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.
This circuit from a June 1957 Radio Electgronics is for oscilloscopes of the time with a maximum...
This simple receiver for listening on a crystal phone tunes the range of medium waves. The circuit...
This circuit in a receiver that allows the capture of distant stations with short waves. The...