Active with the output at the high level, this oscillator was found in November 1984 Radio Electronics magazine. The supply can be between 3 and 12 V and the output signal is rectangular.
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...