This PLL with operational amplifiers was found in 1969 documentation. The configuration can be adapted to use modern components. The circuit has a gain of 15 V / V and can operate with 10 kHz signals.
This circuit is from a Radio Electronics magazine from December 1958. The indicator instrument is analog...
This circuit sends signals to a shortwave radio (range 3 to 7 MHz) at a distance of a few tens of...
This circuit was found in an Electronics World of 1968. It can be applied to any modern triac and...