Uninterruptible power supply (UPS) second disconnection circuit and second disconnection method

Abstract

The invention relates to a UPS second disconnection circuit and a second disconnection method. the circuit comprises a plurality of dial switch I / O-N, the input end is electrically connected with a DSP chip, the output end is connected with a base electrode of an audion QN, an emitting electrode of the audion QN is grounded, a collector electrode is connected with one end of a relay JQN coil, the other end of the coil is connected with a power supply VCC end, a normally-closed contact 3 is connected with loads, and a public end 4 is connected with a UPS output end. The 0 position of the dial switch is set to be unlimited by UPS battery voltages, and the loads are disconnected after the UPS battery voltages are discharged. 1 position is set to be that the UPS output is disconnected with corresponding loads through the relay JQN when the battery voltages are reduced to respective thresholds. By means of the circuit and the method, power supply for secondary loads can be cut off automatically during outage of the mains supply, the circuit can be connected automatically after the mains supply is restored to be normal, and accordingly, the main load back-up time is prolonged; the circuit safety is reliable, the cost is low, and damage to the batteries due to discharging of large currents is prevented.

Description

technical field [0001] The invention relates to the technical field of UPS, in particular to a UPS secondary power-off circuit and a secondary power-off method. Background technique [0002] UPS, uninterruptible power supply, is a system device that connects batteries (mostly lead-acid maintenance-free batteries) with the host, and converts direct current into commercial power through modular circuits such as the host inverter. It is mainly used to provide stable and uninterrupted power supply to a single computer, computer network system or other power electronic equipment. When the mains input is normal, the UPS will stabilize the mains and supply it to the load. At this time, the UPS is an AC mains voltage stabilizer, and it also charges the battery inside the machine; when the mains is interrupted (accident power failure) , the UPS will continue to supply 220V AC power to the load through the zero-switching conversion method of the DC power of the battery immediately, s...

AI Technical Summary

Problems solved by technology

[0003] When UPS supplies power to loads, multiple loads are generally connected together. When the mains power fails, the delay time of important loads will be greatly shortened, seriously affecting the work of important loads, causing heavy losses, and even endangering personal safety.

[0004] In addition, when the UPS supplies power to multiple loads at the same time, it will be in a high-current discharge state for a long time, which will affect the battery life and may damage the battery in severe cases.

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