We found this circuit in the October 1996 Electronics Now magazine. The circuit uses LDRs as sensors and drives relays. The relays must have voltages according to the power supply.
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...