This circuit turns off a relay after a time determined by C1. The circuit was found in the December 1974 Radio Electronics magazine. The relay is rated according to the supply voltage.
This original 70s RCA circuit appears elsewhere on this site, including original RCA...
This circuit, which makes an astable multivibrator, was found in the March 1973 issue of Radio...
This circuit uses two unijunction transistors and only one capacitor, generating signals at a...