Another of the many tachometer circuits we have on our site. This one is from the September 1976 Radio Elecronics magazine. The circuit is connected to the platinum contacts of a car or to a sensor.
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...