The main feature of this circuit found in an old American publication is that it is powered by the very signal it converts. The transistors are of the time and can be replaced by current types.
This 1995 circuit directly controls a triac. The triac, in turn, controls the external load. Times...
A divide-by-4 or two-bit binary counter can also be built using two flip-flops of the 4027 type as...
Using period transistors, this 10 W amplifier was found in Radio Electronics magazine from May...