This 100 second timer was found in the September 1992 issue of Radio Electronics magazine. The circuit has two timing ranges and time adjustment at R6.
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...