This sophisticated circuit for the 90s car was found in the 1993 edition of Radio Electronics Special Projects. It uses components that are still common today.
We found this circuit in a 1960 Sylvania transistor manual. The relay can be 12 V and C1...
The basic siren configuration shown in figure 1 activates a piezoelectric transducer and can be...
One flip-flop of the 4018 can be used as a frequency divider or counter as shown here. Frequency...