We found this circuit in the February 1987 issue of Radio Electronics magazine. It is based on an integrated RCA triac trigger available at the time. The circuit powers 4 incandescent lamps.
The circuit in the figure can be used to trigger a triac or even a comparator in a project that...
Suggested by a 90s Electronic Design, this circuit drains only 0.25 mA from its source. Listening...
Found in a 1960 Sylvania manual, this circuit can be implemented with a modern equivalent...