Found in an Electronic Design from the 90s, this circuit measures the phase difference between two signals using an electronic multimeter. The circuit makes use of components of the time.
This circuit, found in an American publication from the 1970s, produces an audible tone in a...
This circuit was found in a 2006 publication. It can serve as the basis for a microcontrolled...
By adding a transistor to the output and some polarization features we can obtain a higher output...