Control circuit with functions of maintaining time prolonging and undervoltage locking

The utility model relates to a control circuit capable of prolonging holding time and under-voltage locking. A converter is mainly composed of a transformer, a first diode, a control unit, a second switch unit, a first switch unit, a booster circuit, an energy storage capacitor, a third switch unit, a rectifying circuit, a voltage regulating resistor, an under-voltage locking circuit, an output circuit and the like. Therefore, no matter whether a user has a customized undervoltage locking voltage or not, the user can have the same holding time, and the practical effect characteristic is increased in overall implementation and use. 一种兼具延长维持时间及欠压锁定的控制电路，其主要是令转换器分别由变压器、第一二极管、控制单元、第二开关单元、第一开关单元、升压电路、储能电容、第三开关单元、整流电路、调压电阻、欠压锁定电路、输出电路等所组成；籍此，不论使用者有无自订欠压锁定电压，皆能拥有相同的维持时间，而在其整体施行使用上更增实用功效特性。