This 555 IC circuit was found in June 1984 Radio Electronics magazine. This circuit detects a change in the signal and can power a relay or other warning system.
The given number circuit is used to activate the relay by interrupting the light beam that hits...
In the figure we have a simple and efficient way to obtain rectangular signals from an astounding 555...
This circuit, for 78xx series integrated devices, is suggested by Motorola in its 1990 Linear...