POWER SUPPLY DEVICE

摘要

The supply eliminates the unnecessary power consumption of the power supply by selectively driving the internal circuit. The supply device includes: (a) a voltage detector(40) which detects the secondary part voltage of the trans(T); (b) a comparing circuit(50) which determines the voltage or current feedback mode by comparing the reference voltage with the detector(40) output; (c) a mode switching block(60) which determines the battery(70) charge states by determining the threshold level. The mode switching block(60) contains a transistor which controls the reference voltage of the comparator(U1) according to the mode change signal.