We found this circuit in the June 1991 issue of Radio Electronics magazine. The integrated circuit is still available. The table gives the component values.
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...