Adaptive Adjustable Inrush Current Limiter

Abstract

The present invention comprises at least a current limiting resistor, a voltage detection unit, an adjustment unit, a relay control unit, and a relay to form an adaptively adjusted surge current limiter. In particular, when the start-up time of a power supply unit including the inrush current limiter is less than the pull-in time of the relay, the adjustment unit will depend on whether a resistance voltage detected by the voltage detection unit exceeds a threshold value And output an adjustment signal to the relay control unit, so that the relay control unit controls the relay to perform a pull-in switching operation in advance. On the contrary, when the start-up time of the power supply device is greater than the pull-in time of the relay, the relay control unit will control the relay to perform the pull-in switching operation after a delay time has elapsed. In short, the inrush current limiter of the present invention can adaptively adjust the pull-in time of the relay according to the different start-up times of different power supply devices.

Description

technical field [0001] The present invention relates to the related technical field of power supply devices, in particular, to a surge current limiter coupled between an AC power supply and a main power supply unit (PSU). In particular, the inrush current limiter can adaptively adjust the pull-in time of its internal relay according to the specific start-up time of the matched PSU. Background technique [0002] The input end of the Switch Mode Power Supply (SMPS) is usually equipped with a bulk capacitor, which is used for filtering and rectifying the input AC power together with the bridge rectifier. However, this large capacitor will be equivalent to a short circuit when the switching power supply is turned on, thus generating a large inrush current. Therefore, the traditional approach is to use a negative temperature coefficient (NTC) resistor to suppress this inrush current, however this simple method has many disadvantages including: (1) the current limiting effect is ...

AI Technical Summary

Problems solved by technology

[0004] In more detail, when having figure 1 When a power supply unit (PSU) of the inrush current limiter 1' is in operation, if the startup time (Setup time) of the power supply unit is less than the pull-in time of the relay 12', the power supply unit will The relay 12' is activated many times before the pull-in action is performed, causing a large current to continuously flow through the current-limiting resistor, thereby causing the temperature of the current-limiting resistor to be too high, and finally causing the fuse of the power supply unit to be blown

[0005] As can be seen from the above description, the existing inrush current limiter 1' comprising the control unit 13' still has room for further improvement

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