This circuit is used to detect PLL signals from the 4046 IC. The circuit is from an Electronics Now from October 1994. The indication is made through LEDs.
This sensor circuit for currents of the order of nanoamperes was found in an American...
This circuit was obtained from a 1964 magazine and has some interesting features such as the input...
Suggested by a 90’s Radio Electronics, this circuit automatically activates the recording switch of an...