We found this transistorized circuit in a 1985 documentation. The circuit can operate with voltages from 9 to 12 V and the adjustment of the operating point or input sensitivity is done in P1.
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...