This alarm oscillator was found in the December 1974 issue of Radio Electronics magazine. The power transistor must be equipped with a good heat sink. The Frequency basically is given by C1.
This circuit was found in an English magazine from 1983, but it can be assembled with BC548. The...
This circuit tunes MW radios to apply the signal to a good audio amplifier. The circuit is from an...
The cascade connection of two flip-flops allows division by 4, as shown in the figure. Note that...