The device listed at the link below automatically switch the output between either a 12V (really 13.8V) power supply or a battery depending of if the power supply is on. It says it "uses two 80 ampere Schottky diodes connected as an OR-Gate to isolate the battery and power supply from each other." My question is what is the or gate used for? I understand to diodes to stop the Power supply from sucking power out of the batteries when it is off, but have on idea what advantage an or gate would give.
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