This UPS circuit was published in the March 1985 issue of Radio Electronics magazine. The components used are still common, although some may be difficult to obtain.
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
This circuit, in fact, what it does is a reactivation of the batteries through a brief pulsating...
This circuit, for signals up to 1 MHz, is based on an RCA operational amplifier. The circuit was...