CN202550494U - Field-effect tube overvoltage protection circuit - Google Patents
Field-effect tube overvoltage protection circuit Download PDFInfo
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- CN202550494U CN202550494U CN2012201202454U CN201220120245U CN202550494U CN 202550494 U CN202550494 U CN 202550494U CN 2012201202454 U CN2012201202454 U CN 2012201202454U CN 201220120245 U CN201220120245 U CN 201220120245U CN 202550494 U CN202550494 U CN 202550494U
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- 230000005669 field effect Effects 0.000 title abstract description 12
- 239000003990 capacitor Substances 0.000 claims description 23
- 239000003381 stabilizer Substances 0.000 claims description 11
- 238000001514 detection method Methods 0.000 abstract description 7
- 239000004065 semiconductor Substances 0.000 abstract description 5
- 230000001681 protective effect Effects 0.000 abstract description 2
- 230000002159 abnormal effect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 1
- 230000036581 peripheral resistance Effects 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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Abstract
The utility model provides a field-effect tube overvoltage protection circuit. The circuit comprises a rectification module, a high voltage detection and control module and a field-effect tube, wherein the high voltage detection and control module is electrically connected to the rectification module; a grid electrode of the field-effect tube is electrically connected to the high voltage detection and control module; a source electrode of the field-effect tube is electrically connected to the rectification module; and a drain electrode of the field-effect tube is used for connecting a load main functional circuit. A semiconductor field-effect tube is taken as a protective switch of the overvoltage protection circuit, and the high voltage detection and control module detects network voltage and outputs a control level to control the field-effect tube to be switched on and off, so that the main functional circuit is controlled to be closed or opened; the field-effect tube is a non-contact switch, mechanical action is eliminated, and spark is avoided, so that the field-effect tube overvoltage protection circuit is long in service life and high in safety; and the required power for driving the field-effect tube is low, so that energy is saved.
Description
Technical field
The utility model relates to a kind of overvoltage protection field, relates in particular to a kind of excess voltage protection that adopts the FET design.
Background technology
There is not excess voltage protection in the general electric equipment products mostly, as shown in Figure 1, in case electrical network occurs unusually, when voltage fluctuation raises, just have the situation generation that electrical equipment damages.
As shown in Figure 2; In order to address this problem; Some product has adopted relay J as protection switch, and the closed or disconnection in control circuit loop is when testing circuit detects the rising of electrical network abnormal voltage; Control relay cuts off the input power supply, raises and the danger of damage thereby protected the electric equipment products internal circuit to avoid the electrical network abnormal voltage.This relay J power is higher, can increase circuit power consumption to a certain extent, and this will cause energy waste, and the contact of relay J contact the time can produce spark, and reduce useful life relatively, has certain potential safety hazard.
The utility model content
The purpose of the utility model is to provide a kind of FET excess voltage protection, utilizes the protection switch of semiconductor field as excess voltage protection, and this FET is a noncontacting switch; There is not mechanical action; No-spark produces, and long service life is safe; And it is low to drive the required power of FET, saves the energy.
For realizing above-mentioned purpose; The FET excess voltage protection that the utility model provides; Comprise: rectification module, high pressure detect control module and FET; Said high pressure detects control module and is electrically connected at said rectification module; The grid of said FET is electrically connected at said high pressure and detects control module; The source electrode of said FET is electrically connected at said rectification module; The drain electrode of said FET is used to connect the load primary function circuit, and said high pressure detects control module and comprises: first diode, second diode, first filter capacitor, second filter capacitor, voltage-stabiliser tube, voltage reference chip, first resistance, second resistance, the 3rd resistance, the 4th resistance, the 5th resistance and the 6th resistance, said first diode be electrically connected at rectification module after the first filter capacitor forward is connected; Be connected to the anode and the negative electrode of first filter capacitor after said first resistance, second resistance and the series connection of the 3rd resistance; The input pin of said voltage reference chip is electrically connected in the middle of said second resistance and the 3rd resistance, and the grounding pin of said voltage reference chip is connected to the negative electrode of first filter capacitor, and said second filter capacitor is electrically connected at the input pin and the grounding pin of said voltage reference chip; Said the 4th resistance be connected to the negative electrode of first diode and the grid of FET after second diode forward is connected; The output pin of said voltage reference chip is electrically connected at the anode of said second diode, and said voltage-stabiliser tube forward is connected in the grounding pin and the output pin of voltage reference chip, and said the 5th resistance one end is electrically connected in the middle of first resistance and second resistance; The other end is electrically connected at the drain electrode of FET, and said the 6th resistance is electrically connected at the grid of FET and the negative electrode of first filter capacitor.
Said rectification module is a bridge rectifier.
The puncture voltage of said voltage-stabiliser tube is preferably 15V less than the fet gate ceiling voltage.
The beneficial effect of the utility model: the FET over-voltage protection method that the utility model provides, utilize the protection switch of semiconductor field as excess voltage protection, detect the height of control module detection of grid voltage through high pressure and export conducting and the shutoff that control level is controlled FET; Thereby the closure and the disconnection of control primary function circuit; This FET is a noncontacting switch, does not have mechanical action, and no-spark produces; Long service life; Safe, and it is low to drive the required power of FET, saves the energy.
In order further to understand the characteristic and the technology contents of the utility model, see also following detailed description and accompanying drawing, yet accompanying drawing only provides reference and explanation usefulness, is not to be used for the utility model is limited about the utility model.
Description of drawings
Below in conjunction with accompanying drawing, describe in detail through embodiment the utility model, the technical scheme that makes the utility model and other beneficial effect is obvious.
In the accompanying drawing,
Fig. 1 is the circuit diagram of existing no field effect pipe excess voltage protection;
Fig. 2 is the existing circuit block diagram that adds relay protection;
Fig. 3 is the module diagram of the utility model FET excess voltage protection;
Fig. 4 is the circuit diagram of the utility model FET excess voltage protection.
Embodiment
For further setting forth technological means and the effect thereof that the utility model is taked, be described in detail below in conjunction with the preferred embodiment and the accompanying drawing thereof of the utility model.
See also Fig. 3 and 4; The FET excess voltage protection that the utility model provides; It comprises: rectification module 1, high pressure detect control module 2 and FET Q1; Said high pressure detects control module 2 and is electrically connected at said rectification module 1; The grid G of said FET Q1 is electrically connected at said high pressure and detects control module 2; The source S of said FET Q1 is electrically connected at said rectification module 1; The drain D of said FET Q1 is used to connect load primary function circuit 3; Said high pressure detects control module 2 and comprises: the first diode D1, the second diode D2, the first filter capacitor E1, the second filter capacitor C1, voltage-stabiliser tube ZD1, voltage reference chip U1, first resistance R 1, second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5 and the 6th resistance R 6; The said first diode D1 be electrically connected at rectification module 1 after the first filter capacitor E1 forward is connected, be connected to anode and the negative electrode of the first filter capacitor E1 after said first resistance R 1, second resistance R 2 and 3 series connection of the 3rd resistance R, the input pin R of said voltage reference chip U1 is electrically connected at said second resistance R 2 and the 3rd resistance R 3 centres; The grounding pin A of said voltage reference chip U1 is connected to the negative electrode of the first filter capacitor E1; The said second filter capacitor C1 is electrically connected at input pin R and the grounding pin A of said voltage reference chip U1, said the 4th resistance R 4 and the grid G that is connected to negative electrode and the FET Q1 of the first diode D1 after the second diode D2 forward is connected, and the output pin K of said voltage reference chip U1 is electrically connected at the anode of the said second diode D1; Said voltage-stabiliser tube ZD1 forward is connected in grounding pin A and the output pin K of voltage reference chip U1; Said the 5th resistance R 5 one ends are electrically connected in the middle of first resistance R 1 and second resistance R 2, and the other end is electrically connected at the drain D of FET Q1, and said the 6th resistance R 6 is electrically connected at the grid G of FET Q1 and the negative electrode of the first filter capacitor E1.
In the present embodiment; The bridge rectifier of said rectification module 1 for constituting by four diodes, the LM431 that said voltage reference chip U1 adopts National Semiconductor to produce, it can be through adjusting the output voltage that peripheral resistance obtains 2.5V to 36V; So be not limited thereto; Voltage reference chip U1 also can select the compatible chip of similar functions such as TL431, CL431, UTC431 for use, and the puncture voltage of said voltage-stabiliser tube ZD1 is slightly less than the ceiling voltage of fet gate, is preferably 15V.
The utility model operation principle is following: between rectification module 1 and load primary function circuit 3, add a high pressure and detect control module 2 and FET Q1; After grid alternating current is through rectification module 1 rectification, become full-wave direct current; To 3 power supplies of load primary function circuit, the FET Q1 between rectification module 1 and load primary function circuit 3 plays a protective role to load primary function circuit 3.When line voltage just often, high pressure detects control module 2 grid G of a high level to FET Q1 is provided, control FET Q1 conducting; Load primary function circuit 3 can operate as normal, and when the electrical network abnormal voltage raise, high pressure detected control module 2 grid G of a low level to FET Q1 is provided; Control FET Q1 breaks off; Load primary function circuit 3 deenergizations quit work, thereby protection load primary function circuit is avoided the harm that the electrical network abnormal voltage raises.
The concrete course of work is following: the full-wave direct current electricity Vdc that after rectification module 1 rectification, obtains; Through forming a direct voltage V1 more stably after the first filter capacitor E1 filtering; This direct voltage V1 provides working power for high pressure detects control module 2 on the one hand, on the other hand as the identification signal of line voltage.Direct voltage V1 connects through resistance R 1, R2, R3 after the dividing potential drop; Form voltage V2 and voltage V3; Voltage V3 delivers to the input pin R of voltage reference chip U1; U1 provides voltage detection signal for the voltage reference chip, and simultaneously direct voltage V1 forms a stable voltage V4 through the 4th resistance R 4, voltage-stabiliser tube ZD1, for voltage reference chip U1 and FET Q1 provide operating voltage.The second filter capacitor C1 improves high pressure and detects the precision that control module 2 detects voltage the further filtering of voltage signal of the input pin R of voltage reference chip U1 in the circuit.
When line voltage just often; Resistance through adjusting first resistance, second resistance and the 3rd resistance R 1, R2 and R3 can obtain voltage V3 less than 2.5V, and the voltage of input pin R that is to say voltage reference chip U1 is less than 2.5V, this moment voltage reference chip U1 output pin K output high level; Add voltage-stabiliser tube ZD1 qualification effect; Therefore above-mentioned voltage V4 is 15V, and this moment, the grid G voltage Vg of FET Q1 was about 14.3V (voltage V4 deducts the pipe of the second diode D2 and presses (about 0.7V), obtains 14.3V); So this moment, FET Q1 was in complete conducting state, load primary function circuit 3 can operate as normal.
When the electrical network abnormal voltage surpassed normal value, relevant voltage V3 can be greater than 2.5V, and the voltage at input pin R place that is to say voltage reference chip U1 is greater than 2.5V; The output pin K output low level of voltage reference chip U1; This moment, above-mentioned voltage V4 was 2.5V (minimum output voltage of voltage reference chip U1), and this moment, the grid G voltage Vg of FET Q1 was about 1.8V (voltage V4 deducts the pipe of the second diode D2 and presses (0.7V), obtains 1.8V); So this moment, FET Q1 was in complete off state; Load primary function circuit 3 is broken off with electrical network fully, does not receive the influence of electrical network abnormally high-voltage, thereby has realized the purpose of protection load primary function circuit 3.
Said the 5th resistance R 5 plays feedback return difference control action.When voltage V3 was raised to 2.5V, FET Q1 turn-offed, and voltage V5 becomes high voltage Vdc, and this high voltage Vdc makes voltage V2 and voltage V3 correspondingly further raise through 5 positive feedbacks of the 5th resistance R again, guaranteed that voltage V3 surpasses 2.5V, the reliable conducting of FET Q1.Otherwise when voltage V3 dropped to 2.5V, FET Q1 conducting voltage V5 became low-voltage, and this low-voltage makes voltage V2 and voltage V3 further reduce accordingly through 5 positive feedbacks of the 5th resistance R again, guarantees that voltage V3 is lower than 2.5V, and FET Q1 is reliable turn-off then.
In sum, the FET over-voltage protection method that the utility model provides utilizes the protection switch of semiconductor field as excess voltage protection; Detect the height of control module detection of grid voltage through high pressure and export the conducting and the shutoff of control level control FET, thereby control the closure and the disconnection of primary function circuit, this FET is a noncontacting switch; There is not mechanical action; No-spark produces, and long service life is safe; And it is low to drive the required power of FET, saves the energy.
The above; For the person of ordinary skill of the art; Can make other various corresponding changes and distortion according to the technical scheme and the technical conceive of the utility model, and all these changes and distortion all should belong to the protection range of the utility model claim.
Claims (3)
1. FET excess voltage protection; It is characterized in that; Comprise: rectification module, high pressure detect control module and FET; Said high pressure detects control module and is electrically connected at said rectification module; The grid of said FET is electrically connected at said high pressure and detects control module; The source electrode of said FET is electrically connected at said rectification module; The drain electrode of said FET is used to connect the load primary function circuit, and said high pressure detects control module and comprises: first diode, second diode, first filter capacitor, second filter capacitor, voltage-stabiliser tube, voltage reference chip, first resistance, second resistance, the 3rd resistance, the 4th resistance, the 5th resistance and the 6th resistance, said first diode be electrically connected at rectification module after the first filter capacitor forward is connected; Be connected to the anode and the negative electrode of first filter capacitor after said first resistance, second resistance and the series connection of the 3rd resistance; The input pin of said voltage reference chip is electrically connected in the middle of said second resistance and the 3rd resistance, and the grounding pin of said voltage reference chip is connected to the negative electrode of first filter capacitor, and said second filter capacitor is electrically connected at the input pin and the grounding pin of said voltage reference chip; Said the 4th resistance be connected to the negative electrode of first diode and the grid of FET after second diode forward is connected; The output pin of said voltage reference chip is electrically connected at the anode of said second diode, and said voltage-stabiliser tube forward is connected in the grounding pin and the output pin of voltage reference chip, and said the 5th resistance one end is electrically connected in the middle of first resistance and second resistance; The other end is electrically connected at the drain electrode of FET, and said the 6th resistance is electrically connected at the grid of FET and the negative electrode of first filter capacitor.
2. FET excess voltage protection as claimed in claim 1 is characterized in that, said rectification module is a bridge rectifier.
3. FET excess voltage protection as claimed in claim 1 is characterized in that the puncture voltage of said voltage-stabiliser tube is less than the fet gate ceiling voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012201202454U CN202550494U (en) | 2012-03-27 | 2012-03-27 | Field-effect tube overvoltage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012201202454U CN202550494U (en) | 2012-03-27 | 2012-03-27 | Field-effect tube overvoltage protection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN202550494U true CN202550494U (en) | 2012-11-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012201202454U Expired - Lifetime CN202550494U (en) | 2012-03-27 | 2012-03-27 | Field-effect tube overvoltage protection circuit |
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| CN (1) | CN202550494U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109494681A (en) * | 2017-09-13 | 2019-03-19 | 罗伯特·博世有限公司 | Control signal for electrical equipment protects circuit |
-
2012
- 2012-03-27 CN CN2012201202454U patent/CN202550494U/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109494681A (en) * | 2017-09-13 | 2019-03-19 | 罗伯特·博世有限公司 | Control signal for electrical equipment protects circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: SHENZHEN LONGOOD INTELLIGENT ELECTRIC CO., LTD. Free format text: FORMER NAME: SHENZHEN LONGOOD ELECTRONICS CO., LTD. |
|
| CP01 | Change in the name or title of a patent holder |
Address after: Baoan District Shiyan street Shenzhen city Guangdong province 518000 house community AI Qun Lu with rich Industrial Zone No. 8-4 1, 2, 3 floor, building 5 floor left Patentee after: Shenzhen Longood Intelligent Electric Co., Ltd. Address before: Baoan District Shiyan street Shenzhen city Guangdong province 518000 house community AI Qun Lu with rich Industrial Zone No. 8-4 1, 2, 3 floor, building 5 floor left Patentee before: Shenzhen Langke Electrical Appliance Co., Ltd. |
|
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20121121 |