CN217607472U

CN217607472U - Improved overvoltage protection circuit

Info

Publication number: CN217607472U
Application number: CN202123417826.2U
Authority: CN
Inventors: 罗坚; 刘九龙; 肖帅; 王泉观
Original assignee: Huizhou Jinbaize Iot Technology Co ltd
Current assignee: Huizhou Jinbaize Iot Technology Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-10-18
Anticipated expiration: 2031-12-31

Abstract

The utility model provides an improved generation overvoltage protection circuit, including fuse, zener diode, thyristor, divider resistance spare includes parallelly connected first resistance, the second resistance that sets up, fuse, zener diode, divider resistance spare are established ties and are set up; the voltage stabilizing diode and the thyristor are arranged in parallel. The utility model discloses effectual protection load circuit avoids the load to cause the device to damage the dysfunction because of voltage fluctuation. Meanwhile, the damage of the device of the CROWBAR protection circuit is reduced, and the maintenance and device purchase cost is reduced.

Description

Improved overvoltage protection circuit

Technical Field

The utility model belongs to the technical field of the voltage protection circuit, concretely relates to improved generation overvoltage protection circuit.

Background

The CROWBAR circuit is an overvoltage protection circuit, and the design idea of the CROWBAR circuit is that when the power supply voltage exceeds a preset value, the power supply is short-circuited, and the power supply voltage is pulled down through the short circuit. Over-current protection devices such as fuses on the power supply path then act to cut off the power supply to prevent damage to the power supply.

The CROWBAR circuit has the function of monitoring voltage, and when the voltage exceeds a limit value, the silicon controlled rectifier is conducted to form short-circuit current to cause fuse blowing, so that the purpose of protecting a load circuit is achieved.

In the prior art, the following disadvantages exist:

1. the circuit is easily influenced by external interference to cause false triggering, so that the load circuit is powered off and works abnormally;

2. the voltage-stabilizing diode is easy to cause the damage of the branch voltage-dividing resistor after being conducted;

3. the absence of current limiting for the thyristor G-pole is likely to cause transistor damage.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides an improved generation overvoltage protection circuit.

The technical scheme of the utility model is that:

an improved overvoltage protection circuit is characterized by comprising a fuse, a voltage stabilizing diode, a thyristor and a voltage dividing resistance piece, wherein the voltage dividing resistance piece comprises a first resistor and a second resistor which are arranged in parallel; the voltage stabilizing diode and the thyristor are arranged in parallel.

The utility model discloses a theory of operation does: the large voltage can lead to the conduction of the voltage stabilizing diode, the voltage drop generated on the first resistor and the second resistor circuit can convey the gate pole of the thyristor, so that the thyristor is quickly turned on, the surge or continuous abnormal voltage is quickly absorbed, a large enough current is generated at the same time, the fuse is quickly fused, the power supply is disconnected, and the purpose of protecting the load is finally achieved.

Further, the circuit also comprises a peak absorption circuit, and the peak absorption circuit is arranged in parallel with the thyristor.

Further, the spike absorption circuit is arranged in parallel with the voltage division resistance member.

Further, the spike absorption circuit comprises a third resistor and a capacitor which are arranged in series.

Further, the high-voltage power supply further comprises a fourth resistor, and the fourth resistor is connected with the thyristor in series.

The fuse, the diode and the load resistor are sequentially connected in series.

Furthermore, the diode is respectively connected with the voltage stabilizing diode and the thyristor in a parallel connection mode.

Furthermore, the first resistor and the second resistor are both metal oxide film resistors. The metal oxide film resistor is made of special metal or alloy as resistor material and is formed into oxide resistor film on ceramic or glass by vacuum evaporation or sputtering process, so that the current can be limited to required value and has excellent current limiting effect.

Through the utility model discloses, when the circuit voltage that takes place lasts and is higher than operating voltage, this circuit can reach the purpose of protection back stage load through drawing through the thyristor fast. Meanwhile, under the abnormal condition, only the fuse is fused during the circuit protection, and after the fuse is replaced, other circuits can be repeatedly used, so that the cost of damaging and replacing other devices except the fuse is reduced.

The utility model discloses can play fine zener diode branch road guard action. When the voltage stabilizing diode is conducted, the voltage on the branch voltage dividing first resistor and the voltage on the branch voltage dividing second resistor suddenly rise, so that the resistors are easily damaged; and the utility model discloses a parallelly connected form increase discharge capacity of two resistances of first resistance and second resistance adopts the metal oxide film that impact resistance is excellent as current-limiting resistance simultaneously.

The utility model discloses can play fine thyristor protection. Because the gate pole of the thyristor has limited same-current capability, the fourth resistor connected in series with the gate pole is used for limiting current in the process of switching on the thyristor, and the irreversible damage of surge inrush current to the thyristor is prevented.

The utility model discloses can play fine mistake proofing touch guard action. The CROWBAR circuit does not act under the normal working state of a power supply, but the circuit often has some uncontrollable interference pulses which may cause the wrong conduction of the thyristor, so that a peak absorption circuit formed by connecting a third resistor and a capacitor in series is added at the gate level of the thyristor, and the safe and stable operation of the circuit is ensured.

The beneficial effects of the utility model reside in that:

the utility model discloses effectual protection load circuit avoids the load to cause the device to damage the dysfunction because of voltage fluctuation. Meanwhile, the damage of the CROWBAR protection circuit is reduced, and the maintenance and device purchase cost is reduced.

Drawings

Fig. 1 is a schematic diagram of the circuit structure of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1

An improved overvoltage protection circuit is characterized by comprising a fuse F1, a voltage stabilizing diode D1, a thyristor V1 and a voltage dividing resistance piece (not labeled), wherein the voltage dividing resistance piece comprises a first resistor R1 and a second resistor R2 which are arranged in parallel, and the fuse F1, the voltage stabilizing diode D1 and the voltage dividing resistance piece are arranged in series;

the voltage stabilizing diode D1 and the thyristor V1 are arranged in parallel.

Further, the circuit also comprises a peak absorption circuit RC, and the peak absorption circuit RC is connected with the thyristor V1 in parallel.

Further, the spike absorption circuit RC is connected in parallel with the voltage dividing resistance member.

Further, the spike absorption circuit RC includes a third resistor R3 and a capacitor C1, which are connected in series.

Further, the high-voltage power supply also comprises a fourth resistor R4, and the fourth resistor R4 is connected with the thyristor V1 in series.

Further, the fuse protector further comprises a diode D2 and a load resistor R, wherein the fuse F1, the diode D2 and the load resistor R are arranged in series.

Further, the voltage stabilizing diode D1, the thyristor V1 and the diode D2 are arranged in parallel.

Furthermore, the first resistor R1 and the second resistor R2 are both metal oxide film resistors.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art. It should be noted that the technical features not described in detail in the present invention can be implemented by any prior art.

Claims

1. An improved overvoltage protection circuit is characterized by comprising a fuse, a voltage stabilizing diode, a thyristor and a voltage dividing resistance piece, wherein the voltage dividing resistance piece comprises a first resistor and a second resistor which are arranged in parallel;

the voltage stabilizing diode and the thyristor are arranged in parallel.

2. The improved overvoltage protection circuit of claim 1 further comprising a spike snubber circuit, said spike snubber circuit being disposed in parallel with the thyristor.

3. An improved overvoltage protection circuit according to claim 2 wherein said spike absorbing circuit is disposed in parallel with a voltage divider resistive element.

4. An improved overvoltage protection circuit according to claim 3 wherein said spike absorption circuit includes a third resistor, capacitor arranged in series.

5. The improved overvoltage protection circuit of claim 1 further comprising a fourth resistor, said fourth resistor being arranged in series with the thyristor.

6. The improved overvoltage protection circuit according to claim 1 further comprising a diode and a load resistor, wherein the fuse, the diode and the load resistor are connected in series in sequence.

7. The improved overvoltage protection circuit of claim 6 wherein said diodes are connected in parallel with a zener diode and a thyristor, respectively.

8. The improved overvoltage protection circuit of claim 1 wherein said first and second resistors are metal oxide film resistors.