Found in an American documentation from the 90s, this circuit has a configuration that has been extensively explored in other articles on this site. The FET can be the MPF102 or equivalent.
This circuit uses a resonant reed relay to recognize the frequency of an input signal. Adaptations...
A divide-by-4 or two-bit binary counter can also be built using two flip-flops of the 4027 type as...
This circuit was found in a 2005 Linear Technology component manual. The circuit is full bridge...