This dimmer for incandescent lamps using triac and an LF7237 IC was found in May 1985 Radio Electronics magazine. The circuit supports extension buttons.
Old multimeters used a 22.5 V battery for high resistance measurements. If you have one, you...
This circuit has an opposite action to the previous one, triggering when light falls on the...
This circuit was found in a Popular Electronics from 1991. The transistor could be the BC548. The...