CN107658857A - A kind of switch power over-voltage protection circuit and method - Google Patents
A kind of switch power over-voltage protection circuit and method Download PDFInfo
- Publication number
- CN107658857A CN107658857A CN201710860220.5A CN201710860220A CN107658857A CN 107658857 A CN107658857 A CN 107658857A CN 201710860220 A CN201710860220 A CN 201710860220A CN 107658857 A CN107658857 A CN 107658857A
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- China
- Prior art keywords
- voltage
- pwm chip
- protection
- input
- triode
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
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- Emergency Protection Circuit Devices (AREA)
- Protection Of Static Devices (AREA)
Abstract
A kind of switch power over-voltage protection circuit and method; the protection circuit includes input block and voltage sample control unit; voltage sample control unit includes NPN type triode, voltage-stabiliser tube, decoupling capacitor; sampling resistor and pwm chip; when electricity consumption scene input voltage is too high, by the way that accurately voltage-stabiliser tube, NPN type control the conducting of triode in circuit; power supply chip BO voltages are pulled to low level, triggering pwm chip is stopped.When input voltage recovers, NPN type triode is ended, power up normal work.This circuit input voltage scope is wide, using flexible；Overvoltage protection self- recoverage；Protect uniformity good；Simple circuit, cost are relatively low.
Description
Technical field
The present invention is used for intelligence and matches somebody with somebody electric terminal, more particularly to concentrator terminal, special transformer terminals, and negative control distribution transformer terminals etc. are opened
A kind of switch power over-voltage protection circuit and method in powered-down source.
Background technology
At present, intelligence is distributed in adapted power network links with electric terminal, and its input voltage is due to external interference, load
The reasons such as change, laod unbalance can constantly fluctuate and saltus step, cause intelligence to occur at the scene in use with electric terminal：1、
Overvoltage, the live power utilization environment of respective regions is very lack of standardization, and the mode of connection is intricate, can often be monitored at electricity consumption scene
To there is abnormal pressure phenomenon, once monitored that the phase voltage of three phase supply had reached 500Vac at the scene, for operating voltage model
Enclose and be arranged on 60-440Vac intelligence with for electric terminal, input voltage far beyond normal working voltage scope, so as to
Terminal is caused the machine of delaying occur or even damage；2nd, saltus step, flickering, live Voltage unbalance, it there is also instantaneous overvoltage or under-voltage lead
Cause intelligence to restart with electric terminal, report improper power-off event.The present invention uses a kind of power supply overvoltage protection circuit, possesses out
Close electrical source input overvoltage protection auto restore facility.
The content of the invention
The present invention is solves intelligence with can be safe and reliable in the environment of electric terminal at the scene adverse circumstances and catastrophic failure
Operation, the problem of meeting the construction of robustness intelligent grid, it is proposed that a kind of switch power over-voltage protection circuit and method.
The present invention adopts the technical scheme that：
A kind of switch power over-voltage protection circuit, the protection circuit include input block and voltage sample control unit；
Described input block includes rectification circuit and input energy storage filter condenser, and the signal input part of rectification circuit is made
External communication signal is terminated for the signal acquisition of input block, input energy storage filter condenser C1 is in parallel with the rectification circuit even
Connect；The voltage sample control unit includes voltage sampling circuit and pwm chip, and pwm chip is adopted with the voltage
Sample circuit connects；
The rectification circuit is used for convert alternating current is described whole for filtering out into direct current, input energy storage filter condenser
Current circuit exports the ripple of DC voltage, and the voltage sampling circuit passes through the pwm chip for monitoring input voltage
Switching Power Supply control terminal BO be controlled, the pwm chip by decision level obtain power work state, carried out
Pressure protection.
Further, the rectification circuit is the rectification circuit connected and composed by diode bridge type.
Further, the pwm chip selects model NCP1027 or NCP1256.
Further, described voltage sample control unit includes triode, decoupling capacitor C2, sampling resistor R1-R4, surely
Pressure pipe ZD1-ZD2 and pwm chip；Described sampling resistor R1 one end is connected with R2, and resistance R1 and the R2 other end are simultaneously
Input energy storage filter condenser C1 both ends are connected on, voltage-stabiliser tube ZD1 is in parallel with sampling resistor R2, voltage-stabiliser tube ZD1, sampling resistor R1
It is connected with R2 tie point with the Switching Power Supply control terminal BO of pwm chip, sampling resistor R3 one end is connected with R4, resistance
The R3 and R4 other end is attempted by input energy storage filter condenser C1 both ends, and the decoupling capacitor C2 and sampling resistor R4 is simultaneously
Connection, decoupling capacitor C2 are connected with sampling resistor R3, R4 tie point with voltage-stabiliser tube ZD2 negative pole, and voltage-stabiliser tube ZD2 positive pole connects three
The base stage of pole pipe, the colelctor electrode of triode are connected with the Switching Power Supply control terminal BO of pwm chip, and the emitter stage of triode connects
Voltage-stabiliser tube ZD1 positive pole, the pwm chip obtain Switching Power Supply working condition by decision level, realize overvoltage protection.
Further, the decoupling capacitor C2 is CBB electric capacity；The triode is NPN type triode, Vceo/40V, Ic/
0.2A, hFE/100-400, SOT23 are encapsulated.
Further, sampling resistor R1 and sampling resistor R3, according to the protection magnitude of voltage of setting, more resistant series are selected
Use, to meet resistance to pressure request.
A kind of Switching Power Supply over-voltage protection method, application switch power supply overvoltage protection circuit, this method comprise the following steps：
S1, protection voltage is calculated using following formula：
Protect voltage=(R3+R4) × (VZD2+ 0.6V)/R3 formula 1
S2, when input normal voltage i.e. be less than protection voltage constantly, sampling resistor R3 and R4 partial pressure, branch pressure voltage is less than
VZD2+ 0.6V, triode Q1 end, pwm chip normal work；
When input voltage exceedes protection voltage, sampling resistor R3, R4 partial pressure value are more than VZD2+ 0.6V, voltage-stabiliser tube ZD2
Breakdown, NPN type triode Q1 conductings, low level, trigger protection are pulled to by the input voltage of pwm chip BO pin；
S3, in the case of not powering off, input voltage returns to normal voltage range, and voltage-stabiliser tube ZD2 cut-offs, triode Q1 is cut
Only, the voltage of resistance R1, R2 and voltage-stabiliser tube ZD1 regulations pwm chip BO pin, makes pwm chip return to normal condition,
Power up normal work.
Further, according to maximum operation voltage value, as overvoltage protection limit value, corresponding voltage-stabiliser tube ZD2 can be selected
Breakdown voltage.
Beneficial effects of the present invention：
A kind of switch power over-voltage protection circuit of the present invention, possesses wide range input voltage；Possesses Switching Power Supply input
Overvoltage protection auto restore facility；When mistake high pressure once in a while occurs in scene, Switching Power Supply closes work automatically, and voltage recovers normal
Afterwards, Switching Power Supply recovers normal work, and more easily operating environment is provided for on-site maintenance.
Brief description of the drawings
Fig. 1 is the structured flowchart of the present invention.
Fig. 2 is the circuit theory diagrams of the present invention.
Fig. 3 is test result figure of the present invention.
Embodiment
The invention will be further described below in conjunction with the accompanying drawings：
With reference to the structured flowchart of Fig. 1 present invention, the present invention includes input circuit, control unit, by three big portion of protection circuit
Point.
With reference to the circuit theory diagrams of Fig. 2 present invention, the present invention includes ac power input end, rectification circuit, inputs energy storage
Filter condenser, voltage sample control circuit and pwm chip；
Rectification circuit：It is made up of diode D1-D4, is connected with the ac power input end, for by AC rectification
For direct current.
Input energy storage filter condenser C1：It is in parallel with the rectification circuit, for filtering out the rectification circuit output direct current
The ripple of voltage, energy can be stored when input voltage raises, voltage can release energy when reducing, and play the work of flat ripple
With.
Voltage sample control circuit：By control triode Q1, decoupling capacitor C2, sampling resistor R1, sampling resistor R2, sampling
Resistance R3, sampling resistor R4, voltage-stabiliser tube ZD1；Voltage-stabiliser tube ZD2 is formed.Sampling resistor R1, R2 and voltage-stabiliser tube ZD1 composition low pressure open
Dynamic circuit；Sampling resistor R3, R4, decoupling capacitor C2, voltage-stabiliser tube ZD2 and control triode Q1 form over-pressed protection circuit.Fig. 1 institutes
To show, when inputting normal voltage, sampling resistor R3 and R4 partial pressure, branch pressure voltage is less than VZD2+0.6V, and NPN triode Q1 is ended,
Pwm chip normal work.
Protect voltage computing formula：
(R3+R4) × (VZD2+0.6V)/R3 formula 1
When input voltage exceedes the maximum voltage value of design, sampling resistor R3, R4 partial pressure value ＞ VZD2+0.6V, ZD2 are hit
Wear, NPN type triode Q1 conductings, the input voltage of pwm chip BO pin is pulled to low level, trigger protection.Do not powering off
In the case of, input voltage returns to normal voltage range, ZD2 cut-offs, triode Q1 cut-offs, R1, R2, ZD1 regulation PWM control cores
The voltage of piece BO pin, pwm chip is set to return to normal condition, power up normal work.According to maximum operation voltage value,
The overvoltage protection limit value designed, select voltage-stabiliser tube ZD2 breakdown voltage.To prevent power input from receiving coupling or conduction
Impulse disturbances when, can triggers circuit malfunction, decoupling capacitor C2 is added on resistance pressure-dividing network, increases the stabilization of circuit
Property.
Switching Power Supply control terminal BO：It is connected with the voltage sample control circuit output end, PWM chip judges BO pins
Low and high level, for controlling switch power work state.
The present invention solves intelligence and matches somebody with somebody electric terminal in the overvoltage protection of Different field environment and provide the input electricity of ultra-wide
Scope is pressed, when electricity consumption scene input voltage is too high, by the way that accurately voltage-stabiliser tube, NPN type control the conducting of triode in circuit,
Voltage is pulled to low level, triggering pwm chip is stopped.By determining wide input voltage to R1, R2, ZD1 selection
Scope, by determining the over-pressed limit value of input to R3, R4, ZD2 selection.
With reference to Fig. 3 test result figures of the present invention, the present invention set limitation of protection voltage and real protection value error as
0.2%, there is superelevation benchmark degree.
It is described above, it is the embodiment of the present invention, but protection scope of the present invention is not limited thereto, Ren Hekai
Close Power Engineer and be all very familiar with this protected mode, and change or replacement easily.Therefore, protection scope of the present invention is only with right
It is required that protection domain be defined.
Claims (9)
- A kind of 1. switch power over-voltage protection circuit, it is characterised in that：The protection circuit includes input block and voltage sample control Unit processed；Described input block includes rectification circuit and input energy storage filter condenser, and the signal input part of rectification circuit is as defeated Enter the signal acquisition termination external communication signal of unit, input energy storage filter condenser C1 is connected in parallel with the rectification circuit； The voltage sample control unit includes voltage sampling circuit and pwm chip, pwm chip and voltage sample electricity Road connects；The rectification circuit is used to be used to filter out the rectified current into direct current, input energy storage filter condenser by convert alternating current Road exports the ripple of DC voltage, and the voltage sampling circuit is used for monitoring input voltage opening by the pwm chip Close power control terminal BO to be controlled, the pwm chip obtains power work state by decision level, carries out over-pressed guarantor Shield.
- A kind of 2. switch power over-voltage protection circuit according to claim 1, it is characterised in that：The rectification circuit be by The rectification circuit that diode bridge type connects and composes.
- A kind of 3. switch power over-voltage protection circuit according to claim 1, it is characterised in that the pwm chip From model NCP1027 or NCP1256.
- A kind of 4. switch power over-voltage protection circuit according to claim 1, it is characterised in that：Described voltage sample control Unit processed includes triode, decoupling capacitor C2, sampling resistor R1-R4, voltage-stabiliser tube ZD1-ZD2 and pwm chip；Described adopts Sample resistance R1 one end is connected with R2, and resistance R1 and the R2 other end are attempted by input energy storage filter condenser C1 both ends, surely Pressure pipe ZD1 is in parallel with sampling resistor R2, voltage-stabiliser tube ZD1, sampling resistor R1 and R2 tie point and pwm chip switch electricity Source control terminal BO is connected, and sampling resistor R3 one end is connected with R4, and resistance R3 and the R4 other end are attempted by input energy storage filtering Capacitor C1 both ends, the decoupling capacitor C2 is in parallel with sampling resistor R4, decoupling capacitor C2 and sampling resistor R3, R4 connection Point is connected with voltage-stabiliser tube ZD2 negative pole, and voltage-stabiliser tube ZD2 positive pole connects the base stage of triode, and colelctor electrode and the PWM of triode are controlled The Switching Power Supply control terminal BO of chip is connected, and the emitter stage of triode connects voltage-stabiliser tube ZD1 positive pole, and the pwm chip leads to Cross decision level and obtain Switching Power Supply working condition, realize overvoltage protection.
- A kind of 5. switch power over-voltage protection circuit according to claim 4, it is characterised in that：The decoupling capacitor C2 is CBB electric capacity.
- A kind of 6. switch power over-voltage protection circuit according to claim 4, it is characterised in that：The triode is NPN Type triode, Vceo/40V, Ic/0.2A, hFE/100-400, SOT23 encapsulation.
- A kind of 7. switch power over-voltage protection circuit according to claim 4, it is characterised in that：Sampling resistor R1 and sampling Resistance R3, according to the protection magnitude of voltage of setting, more resistant series are selected to use, to meet resistance to pressure request.
- 8. a kind of Switching Power Supply over-voltage protection method, using the switch power over-voltage protection circuit described in one of claim 1-7, It is characterized in that：This method comprises the following steps：S1, protection voltage is calculated using following formula：Protect voltage=(R3+R4) × (VZD2+ 0.6V)/R3 formula 1S2, when input normal voltage i.e. be less than protection voltage constantly, sampling resistor R3 and R4 partial pressure, branch pressure voltage is less than VZD2+ 0.6V, triode Q1 end, pwm chip normal work；When input voltage exceedes protection voltage, sampling resistor R3, R4 partial pressure value are more than VZD2+ 0.6V, voltage-stabiliser tube ZD2 puncture, NPN type triode Q1 is turned on, and the input voltage of pwm chip BO pin is pulled into low level, trigger protection；S3, in the case of not powering off, input voltage returns to normal voltage range, voltage-stabiliser tube ZD2 cut-offs, triode Q1 cut-offs, Resistance R1, R2 and voltage-stabiliser tube ZD1 regulation pwm chip BO pin voltage, make pwm chip return to normal condition, electricity Recover normal work in source.
- 9. a kind of Switching Power Supply over-voltage protection method according to claim 8, it is characterised in that according to maximum operation voltage Value, as overvoltage protection limit value, corresponding voltage-stabiliser tube ZD2 breakdown voltage can be selected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710860220.5A CN107658857A (en) | 2017-09-21 | 2017-09-21 | A kind of switch power over-voltage protection circuit and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710860220.5A CN107658857A (en) | 2017-09-21 | 2017-09-21 | A kind of switch power over-voltage protection circuit and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107658857A true CN107658857A (en) | 2018-02-02 |
Family
ID=61130989
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710860220.5A Pending CN107658857A (en) | 2017-09-21 | 2017-09-21 | A kind of switch power over-voltage protection circuit and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107658857A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108448538A (en) * | 2018-04-03 | 2018-08-24 | 深圳茂硕电子科技有限公司 | A kind of overvoltage crowbar and its method |
| CN109149521A (en) * | 2018-08-09 | 2019-01-04 | 珠海格力电器股份有限公司 | A kind of over-pressure safety device, motor and its over-voltage protection method |
| CN110446300A (en) * | 2019-08-06 | 2019-11-12 | 美芯晟科技（北京）有限公司 | Current ripple removing circuit, related circuit and device |
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| JP2001268902A (en) * | 2000-03-23 | 2001-09-28 | Sharp Corp | Switching power supply |
| CN203026918U (en) * | 2012-11-29 | 2013-06-26 | 无锡市金赛德电子有限公司 | Input over-voltage protection circuit of smart grid terminal power supply |
| KR101311211B1 (en) * | 2012-12-07 | 2013-09-25 | 비엔피전자주식회사 | Smps of led light |
| CN103474965A (en) * | 2013-08-27 | 2013-12-25 | 崧顺电子（深圳）有限公司 | Low-cost alternating-current input overvoltage protection circuit and switching power supply |
| CN203596738U (en) * | 2013-12-19 | 2014-05-14 | 深圳市共进电子股份有限公司 | Switch power supply output overvoltage protection circuit |
| CN206323126U (en) * | 2016-12-28 | 2017-07-11 | 广州视源电子科技股份有限公司 | A kind of AC overvoltage crowbars with runback bit function |
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2017
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001268902A (en) * | 2000-03-23 | 2001-09-28 | Sharp Corp | Switching power supply |
| CN203026918U (en) * | 2012-11-29 | 2013-06-26 | 无锡市金赛德电子有限公司 | Input over-voltage protection circuit of smart grid terminal power supply |
| KR101311211B1 (en) * | 2012-12-07 | 2013-09-25 | 비엔피전자주식회사 | Smps of led light |
| CN103474965A (en) * | 2013-08-27 | 2013-12-25 | 崧顺电子（深圳）有限公司 | Low-cost alternating-current input overvoltage protection circuit and switching power supply |
| CN203596738U (en) * | 2013-12-19 | 2014-05-14 | 深圳市共进电子股份有限公司 | Switch power supply output overvoltage protection circuit |
| CN206323126U (en) * | 2016-12-28 | 2017-07-11 | 广州视源电子科技股份有限公司 | A kind of AC overvoltage crowbars with runback bit function |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108448538A (en) * | 2018-04-03 | 2018-08-24 | 深圳茂硕电子科技有限公司 | A kind of overvoltage crowbar and its method |
| CN109149521A (en) * | 2018-08-09 | 2019-01-04 | 珠海格力电器股份有限公司 | A kind of over-pressure safety device, motor and its over-voltage protection method |
| CN110446300A (en) * | 2019-08-06 | 2019-11-12 | 美芯晟科技（北京）有限公司 | Current ripple removing circuit, related circuit and device |
| CN110446300B (en) * | 2019-08-06 | 2022-05-13 | 美芯晟科技(北京)股份有限公司 | Current ripple removing circuit, related circuit and device |
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