Novel frequency conversion power source protecting device

Abstract

A protective device for a variable-frequency power supply comprises a power resistor, a relay and a negative temperature coefficient thermistor, wherein the power resistor and the negative temperature coefficient thermistor are connected in series between the power supply and an integrated circuit; the relay is connected in parallel with the power resistor and both ends of the negative temperature coefficient thermistor; and a capacitor is connected in parallel with the integrated circuit. The invention includes the resistor satisfying the requirements of a rectification circuit, thereby effectively preventing overvoltage and overcurrent, protecting the capacitor and shortening the charge time.

Description

technical field

[0001] The invention belongs to the field of electrical engineering, and relates to a power protection device, in particular to a frequency conversion power protection device. Background technique

[0002] With the increasing development of electronic technology, variable frequency power supply has been widely used, and the protection device of variable frequency power supply has also attracted much attention. figure 1 As shown) is only composed of a power resistor 11 and a relay 12, and most of them have problems such as that the charging current of the capacitor 14 is still relatively large at the initial stage of power-on; as the voltage of the capacitor 14 increases, the charging current of the capacitor 14 gradually decreases, which makes the charging time longer. .

[0003] and from figure 2 It can be seen that the choice of resistor size has different effects on the rectifier circuit:

[0004] 1) At the initial stage of capacitor charging, the capa...

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