Surge restraint circuit

Abstract

The invention discloses a surge inhibiting circuit, which comprises the following parts: voltage input end, voltage output end, field effect pipe, transistor, capacitance, first resistance, second resistance, wherein the voltage input end connects the source pole of field effect pipe and launching pole of transistor, which also connects the leak pole of field effect pipe through first resistance; the integral electrode of transistor connects ground through the second resistance; the basic pole of transistor connects the integral electrode of transistor and grid and leak pole of field effect pipe; the leak of field effect pipe connects ground through capacitance; the leak pole of field effect pipe connects the voltage output end. The invention can inhibit surge voltage effectively, which reduces the power consumption of stable working effectively due to little inner resistance of transistor and also provides short-circuit load protecting function.

Description

technical field [0001] The invention relates to a power supply protection circuit, in particular to a surge suppression circuit. Background technique [0002] The power switch will generate surge voltage and surge current in an instant. If the surge voltage and surge current are too large, it will damage the electrical appliances or internal components of the power supply. The industry usually uses a negative temperature coefficient thermistor (NTC) to suppress the surge voltage, and uses the high resistance of the NTC at room temperature to limit the surge current. The value is reduced to reduce power loss. This method is simple and easy to implement, but the problem is that the performance of limiting the inrush current is affected by the ambient temperature and the initial temperature of the NTC. When the ambient temperature is high or the power-on time interval is very short, the NTC cannot limit the inrush current. The role of the surge voltage cannot be suppressed. ...

AI Technical Summary

Problems solved by technology

This method is simple and easy to implement, but the problem is that the performance of limiting the inrush current is affected by the ambient temperature and the initial temperature of the NTC. When the ambient temperature is high or the power-on time interval is very short, the NTC cannot limit the inrush current. effect, that is, the inability to suppress the surge voltage

[0003] Another surge suppression method commonly used in the industry is to use series current-limiting resistors. The advantages of this method are simplicity, high reliability, and allowing work in a wide range of ambient temperatures. The disadvantage is that there is loss on the current-limiting resistors, which reduces the Power Efficiency

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