This 555 IC circuit was found in the November 1994 issue of Radio Electronics magazine. The circuit can be powered by voltages from 12 to 24 V.
To operate with high input voltages using a 3-terminal voltage regulator such as the LM340-15, we...
We found this circuit in the October 1988 Radio Electronics magazine. The circuit is still current...
This audio signal relay was found in an American 1980s documentation. The relay is in accordance...