This circuit from a Radio Electronics from December 1974 was used in color televisions of the time. It serves as a reference for restoration work. The circuit is of the ultrasonic type.
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...