We found this circuit in a Popular Electronics of the 90s. The circuit can be easily mounted today, as the components are common. The SCR can be the TIC106.
This circuit contains a voltage doubler that comprises two diodes and two capacitors, in order to...
Radio Electronics magazine published in a 90's issue this simple alarm that can use any general...
This circuit is from the time when slide projects were used. We find it in a 90's Wels’ Think...