Dynamic thermal protection type overvoltage protector

Abstract

The invention relates to a dynamic thermal protection type overvoltage protector. The protector is characterized in that a power input end is connected with a piezoresistor YM2 in parallel and is connected with a resistor R1 in series; the series-connected resistor R1 is a temperature sensitive PTC (Positive Temperature Coefficient) resistor, namely a restorable fuse wire; the power input end is also connected with a controllable load circuit (1) in parallel; the controllable load circuit (1) consists of a controllable load L, a trigger current limiting resistor R2, a transient suppressor D1, a bidirectional controllable silicon Q1, and an anti-interference resistor R3 and a piezoresistor YM3. The controllable load circuit (1), the piezoresistor YM2 and the resistor R1 are all manufactured to be functional modules and mounted into a shell, the leading-in terminals of the functional modules are connected with a power supply and the leading-out terminals of the functional modules are connected with the load. The overvoltage protector can be widely applied to low-power single-phase load circuits, such as home appliances, industrial control instruments, electric power detecting instruments and the like, and has the advantage of limiting the load voltage within a protection voltage range in case of over voltage, without affecting the normal operation of the load circuit.

Description

technical field [0001] The invention relates to an overvoltage protector, in particular to a protector for realizing the overvoltage protection by dynamically adjusting a thermal element when heated. Background technique [0002] At present, there are various devices and circuits in the overvoltage protection circuit of instruments and equipment, such as transient suppression tubes, varistors, thermistors and other devices, which can be used in overvoltage protection circuits. However, most of the overvoltage protection circuits will cut off the power supply or disconnect the load circuit in the overvoltage state, such as varistors, transient suppression tubes, etc. When used in conjunction with a resettable fuse, that is, a PTC thermistor, the overvoltage protection circuit itself In the case of overvoltage, it will be damaged, and the equipment cannot continue to work when the voltage returns to normal. CN1039934A discloses the patented technology of "overvoltage protectio...

AI Technical Summary

Problems solved by technology

However, most overvoltage protection circuits will cut off the power supply or disconnect the load circuit under overvoltage conditions, such as varistors, transient suppression tubes, etc. In the case of overvoltage, it will be damaged, and the equipment cannot continue to work when the voltage returns to normal. CN1039934A discloses the patented technology of "overvoltage protection circuit" of an American company, which belongs to this situation.

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