This circuit was found in the March 1995 issue of Electronics Now magazine. The circuit requires a symmetrical power supply, and the FET is a common general-purpose type.
In the figure we show a timer, this simple one with only one of the four gates of integrated...
This circuit is a sensor for photodiodes that can be used in optical couplers, encoders and other...
This crystal tester was found on a 90s Ham Radio. Transistors are commonly used. The circuit is for...