This dimmer for incandescent lamps using triac and an LF7237 IC was found in May 1985 Radio Electronics magazine. The circuit supports extension buttons.
Because it uses TTL integrated circuits, this siren must be powered by 5 V or as indicated with D1 to...
The correct connection of speakers and tweeters in a speaker to obtain better sound quality,...
The CMOS PLL used on this circuit is not very common. The circuit can be used to take out contact...