This 9 W amplifier with transistors from the 60's was found in documentation of the time. The output transistors must be mounted on heat radiators and the power supply is included.
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...