This circuit was found in the 1992 Radio Electronics Handbook. It is used to test VCR recording heads. It can also be used for other purposes.
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...