This circuit was found in Radio Electronics from the 90s. The CMOS integrated circuit is a PLL not easy to obtain today. The output stage can be exchanged for another one with greater power.
This circuit of a 1978 American publication monitors a telephone line by triggering a relay. The...
This circuit includes a power stage with an integrated circuit that is uncommon today. Equivalents can be...
We found this oscillator in an integrated circuit manual from the 90's. The circuit shows how to...