2 DC UNINTERRUPTABLE POWER SUPPLY FOR SMALL SECTOR BASE STATION AND CHARGING METHOD FOR SECONDARY BATTERY IN THE DC UNINTERRUPTABLE POWER SUPPLY

摘要

According to the present invention, a DC output type uninterruptable power supply device for a small sector base station includes: an AC input part connected to prevailing AC power; a rectification part rectifying the prevailing AC power outputted from the AC input part into a DC voltage; a transformer converting the voltage outputted from the rectification part; a power supply part including a switching transistor coupled with a first coil on a primary side of the transformer, and supplying power to a main coil on a secondary side of the transformer and an intermittent charging coil on the secondary side in accordance with the operation of the switching transistor; a PWM signal generation part receiving a sensing signal corresponding to a current flowing in the switching transistor and a feedback voltage corresponding to a first voltage generated on the main coil; a power failure detecting part placed between an earth and the output of the rectification part, and outputting a power failure detection signal by using the voltage outputted from the rectification part; a small current charging part placed on the side of the output of the main coil on the secondary side in the transformer, and continuously supplying a small current to a secondary battery; and an intermittent charging part placed on the side of the output of the intermittent charging coil on the secondary side in the transformer, and supplying an intermittent charging voltage to the secondary battery in response to an intermittent charging control signal. Therefore, the power supply device is capable of extending the lifespan of a secondary battery by applying an intermittent charging method.