We found this circuit in the November 1992 Radio Electronics magazine. The circuit uses an LDR as a sensor and the transistor can be any general-purpose transistor.
This circuit was found in Texas Instruments documentation from the 1980s. The circuit has a Q less...
We have dozens of similar projects in articles and circuits on this site. This is from Radio...
This circuit provides a signal that is twice the frequency of the input signal. The circuit was...