| 摘要 |
PROBLEM TO BE SOLVED: To provide an uninterruptible power supply which can prevent an overdischarge of a DC power supply, and has high reliability.SOLUTION: In a discharge circuit in which a lithium ion battery formed by a plurality of cells as a DC power supply is used, and discharges them, an uninterruptible power supply comprises: a discharge voltage comparator which outputs 1 when the discharge voltage exceeds an overvoltage level due to an output of a discharge voltage detection circuit; and a discharge final voltage comparator which is constructed by AND element comparing an inverted output of the discharge voltage comparator and the output of a gate signal generation circuit, blocks a submission of a signal for driving the discharge circuit when the discharge voltage exceeds the overvoltage level, and outputs 1 in a circuit submitting the signal for the inverter driving, when a battery voltage is lower than a discharge final level due to output of the battery voltage detection circuit, is constructed by the AND element for comparing the inverted output of discharge final voltage comparator and the output of the gate signal generation circuit of inverter, and blocks the signal for driving the inverter when the battery voltage is lower than the discharge final level.SELECTED DRAWING: Figure 1 |
