Found in a 1964 publication, this circuit makes use of transistors from the time. It operates on frequencies up to 3 kHz.
The purpose of this PLL circuit that we found in the November 1986 Radio Electronics magazine is...
This circuit is intended for detecting 3 levels power grid voltage, and it can be adapted to...
This circuit, which provides a power of up to 3.5 W, can be supplied with voltages from 9 to 14 V....