CN201260063Y - Over-voltage protection circuit based on single power supply voltage and electric appliance device having the circuit - Google Patents
Over-voltage protection circuit based on single power supply voltage and electric appliance device having the circuit Download PDFInfo
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- CN201260063Y CN201260063Y CNU200820026739XU CN200820026739U CN201260063Y CN 201260063 Y CN201260063 Y CN 201260063Y CN U200820026739X U CNU200820026739X U CN U200820026739XU CN 200820026739 U CN200820026739 U CN 200820026739U CN 201260063 Y CN201260063 Y CN 201260063Y
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Abstract
The utility model discloses an over-voltage protection circuit based on the single power supply voltage and an electric device provided with the circuit, which comprises a voltage input end connected with an adapter and a voltage output end connected with a main board power supply end; a voltage dividing circuit is connected at the voltage input end; a voltage dividing node of the voltage dividing circuit is connected with a control end of a first switch component; a switch path of the first switch component is connected between the voltage input end and the control end of a second switch component; and a switch path of the second switch component is connected between the voltage input end and the voltage output end. The over-voltage protection circuit has the advantages that the over-voltage protection circuit structure is simple; the cost is low; the circuit can cut off the power supply for main board circuit on time when the adapter output voltage is over high, so as to control the device to enter into the standby condition and avoid the damage to the module circuits on the main board; thus effectively improving the security and the reliability of the whole system operation and facilitating to enhance the whole quality of the electric devices.
Description
Technical field
The utility model relates to a kind of protective circuit, specifically, relate to a kind of based on single supply power voltage overvoltage crowbar and use the electric equipment of this overvoltage crowbar.
Background technology
In some present household appliances product, often use the adapter single-power voltage to power to main frame, for example be exactly to adopt the 12V adapter to be its inner motherboard circuit power supply in network television-set top-set-box, to satisfy the power supply needs of various modular circuits on the mainboard, realize its normal operation that powers on.For the modular circuit on the mainboard, particularly various functional chips, supply power voltage to input all has certain area requirement, if input voltage is too high, usually be higher than 10% o'clock of standard supply power voltage, will cause damage, thereby influence the normal operation of whole set equipment modular circuit.Therefore, for fail safe and the reliability that improves home appliance, input voltage is carried out overvoltage protection be very important.
And for present overvoltage crowbar; mostly adopt integrated chip that the amplitude of input voltage is detected, when surpassing the emergency exit limit value, such as being higher than 10% o'clock of standard supply power voltage; then cut off the power supply of input voltage, to realize protection to each modular circuit on the mainboard to mainboard.Though the structure of this overvoltage crowbar is simple, cost is higher, therefore, is not suitable for promoting the use of in the fierce relatively household appliances product of price competition.
Based on this, how to design a kind of overvoltage crowbar simple in structure and with low cost and be one of subject matter that present household appliances product design personnel are devoted to solve.
The utility model content
The purpose of this utility model is to provide a kind of overvoltage crowbar based on single supply power voltage; to avoid too high input voltage that the modular circuit on the mainboard is caused damage; set up described overvoltage crowbar by adopting discrete component; under the prerequisite of effectively guaranteeing the electric equipment safe operation, realized the reduction of complete machine cost.
For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:
A kind of overvoltage crowbar based on single supply power voltage comprises voltage input end and voltage output end; On described voltage input end, be connected with a bleeder circuit, the dividing potential drop node of described bleeder circuit connects the control end of first switch element, the switch ways of described first switch element is connected between the control end of described voltage input end and second switch element, and the switch ways of described second switch element is connected between described voltage input end and the voltage output end.
Further, described first switch element is a positive-negative-positive triode, and its base stage connects the dividing potential drop node of described bleeder circuit, and emitter connects described voltage input end, and collector electrode connects the control end of described second switch element.
Certainly, described first switch element also can adopt a P-channel field-effect transistor (PEFT) pipe to realize that its grid connects the dividing potential drop node of described bleeder circuit, and source electrode connects described voltage input end, and drain electrode connects the control end of described second switch element.
Further again, described second switch element preferably adopts a P-channel field-effect transistor (PEFT) pipe to realize that its grid connects described first switch element, and source electrode connects described voltage input end, and drain electrode connects described voltage output end.
Certainly, described first switch element and second switch element also can adopt other switching devices with controlled on-off function to realize.
Further again, described bleeder circuit is formed by connecting by a plurality of divider resistances, dispose the resistance of described divider resistance, make the input voltage of introducing by voltage input end when reaching the emergency exit limit value, described dividing potential drop voltages at nodes just reaches the critical conduction voltage of described first switch element.
Based on above-mentioned overvoltage crowbar structure; the utility model provides a kind of electric equipment with described overvoltage crowbar again; by described overvoltage crowbar being connected between the adapter and mainboard of electric equipment inside; surpass the emergency exit limit value in the adapter output voltage amplitude; it is 10% o'clock of the required standard supply power voltage of mainboard; cut off the supply access between adapter and the mainboard, avoid damaging with each modular circuit on the protection mainboard.
Compared with prior art; advantage of the present utility model and good effect are: overvoltage crowbar of the present utility model is simple in structure; with low cost; when the adapter output voltage is too high, can cut off its power supply in time to motherboard circuit; enter holding state with control apparatus equipment; thereby avoid causing the damage of mainboard upper module circuit, effectively improved the fail safe and the reliability of circuitry system operation, help to improve the complete machine quality of electric equipment.
Description of drawings
Fig. 1 is the circuit theory diagrams of a kind of embodiment of the overvoltage crowbar that proposes of the utility model.
Embodiment
Below in conjunction with the drawings and specific embodiments the utility model is done explanation in further detail.
Overvoltage crowbar of the present utility model can play good overvoltage protection effect to the electric equipment based on single-voltage-supply cmos, mainly comprises voltage input end, voltage output end, bleeder circuit and two switch elements.Wherein, bleeder circuit is connected on the described voltage input end, and the input voltage of introducing by voltage input end is played the dividing potential drop effect, can specifically adopt a plurality of divider resistances to be formed by connecting.The dividing potential drop node of described bleeder circuit is connected with the control end of first switch element, and the resistance by the reasonable disposition divider resistance realizes the accurate control to the first switch element break-make.The switch ways of described first switch element is connected between the control end of voltage input end and second switch element, realizes the break-make of second switch element is controlled by the on off operating mode that changes first switch element.The switch ways of described second switch element is connected between voltage input end and the voltage output end, in the input voltage of introducing by described voltage input end conducting during less than the emergency exit limit value, being communicated with the power supply of adapter to motherboard circuit, the main control system operation that powers on; And end during greater than the emergency exit limit value at input voltage, with the connecting path between blocking-up adapter and the mainboard, avoid too high supply power voltage to cause the damage of motherboard circuit, thereby improve the fail safe and the reliability of electric equipment operation.
Embodiment one, and present embodiment has been enumerated a kind of employing positive-negative-positive triode V1 as first switch element; Adopt P-channel field-effect transistor (PEFT) pipe Q1 to form overvoltage crowbar described in the utility model as the second switch element, concrete structure is referring to shown in Figure 1.
Among Fig. 1, Vin is a voltage input end, can specifically be connected to the power supply that motherboard circuit provides operating voltage, such as the direct current single-power voltage by adapter output.Divider resistance R1, R2 form bleeder circuit, and an end connects voltage input end Vin, other end ground connection, and its dividing potential drop node connects the base stage of positive-negative-positive triode V1.The emitter of described positive-negative-positive triode V1 connects voltage input end Vin, and collector electrode connects the grid of P-channel field-effect transistor (PEFT) pipe Q1, and through resistance R 3 ground connection.The source electrode of described P-channel field-effect transistor (PEFT) pipe Q1 connects voltage input end Vin, and drain electrode connects voltage output end Vcc, and passes through the anode that resistance R 4 connects a light-emitting diode D1, the minus earth of described light-emitting diode D1.
Be specifically addressed as follows to the operation principle that adopts the overvoltage crowbar that the foregoing circuit structure sets up below:
Is example with 12V for the standard supply power voltage; general tolerance voltage is 10% of standard supply power voltage; promptly allow input voltage to be up to about 12+12*10%=13.2V; therefore; with 13.2V is the parameter that safe threshold voltage disposes each components and parts in the above-mentioned overvoltage crowbar; thereby when the direct current supply voltage of introducing by voltage input end Vin is higher than 13.2V, P-channel field-effect transistor (PEFT) pipe Q1 is ended; with the connecting path between blocking voltage input Vin and the voltage output end Vcc; and then the cut-out adapter is to the power supply of motherboard circuit; to avoid too high supply power voltage that each modular circuit on the mainboard is impacted, cause its damage.
Its concrete course of work is: the resistance of configuration divider resistance R1, R2 is respectively 560 Ω and 10K Ω, certainly, this is a kind of embodiment, also the resistance of described divider resistance R1, R2 can be configured to other numerical value, as long as satisfy at the input voltage of introducing by voltage input end Vin when reaching emergency exit limit value 13.2V, the critical conduction voltage that its dividing potential drop voltages at nodes just reaches positive-negative-positive triode V1 gets final product.When input voltage is 13.2V, under the dividing potential drop effect of divider resistance R1, R2, make its dividing potential drop voltages at nodes value 12.5V, the base voltage that is positive-negative-positive triode V1 is 12.5V, at this moment the base stage of triode V1 and the voltage difference between the emitter are Vbe=-0.7V, make triode V1 be in critical conduction mode.
When input voltage was 12V, the base voltage of triode V1 was 11.37V, the voltage Vbe=-0.63V between its base stage and the emitter 〉-0.7V, so triode V1 ends.At this moment, the grid voltage of P-channel field-effect transistor (PEFT) pipe Q1 is 0V, the grid of field effect transistor Q1 and the voltage Vgs=-12V between the source electrode, so field effect transistor Q1 conducting makes VCC=Vin, and lights light-emitting diode D1, the indication motherboard circuit is in power-up state.
When input voltage vin=14V, the base voltage of triode V1 is 13.26V, the voltage Vbe=-0.74 between its base stage and the emitter＜-0.7V, so triode V1 conducting.At this moment, the grid voltage of field effect transistor Q1 is 14V, like this grid of field effect transistor Q1 and the voltage Vgs=0V between the source electrode, therefore, field effect transistor Q1 ends, and the voltage of Vin will can not supplied with VCC, light-emitting diode D1 will can not lighted, and the indication motherboard circuit does not have power supply at this moment and inserts.
Should be noted that: above analysis is hypothesis triode V1 and field effect transistor Q1 is desirable device; in the application of reality; we can dispose suitable divider resistance R1 and the resistance of R2 according to the parameter of selected triode V1 and field effect transistor Q1, to reach the purpose of overvoltage protection.
Certainly, described first switch element and second switch element also can adopt other components and parts with gate-controlled switch effect to realize that the utility model is not limited thereto.But consider that field effect transistor has the advantages that conduction impedance is little, allow big electric current to pass through, and therefore, preferably sets up described overvoltage crowbar as the second switch element.
In sum, the utility model is set up overvoltage crowbar by adopting discrete component, under the prerequisite of guaranteeing the motherboard circuit safe operation, makes the complete machine cost be minimized, and can be widely used in all electric equipments that adopt single-voltage-supply cmos.
Certainly; above-mentioned explanation is not to be to restriction of the present utility model; the utility model also is not limited in above-mentioned giving an example, and variation, remodeling, interpolation or replacement that those skilled in the art are made in essential scope of the present utility model also should belong to protection range of the present utility model.
Claims (10)
1, a kind of overvoltage crowbar based on single supply power voltage comprises voltage input end and voltage output end; It is characterized in that: on described voltage input end, be connected with a bleeder circuit, the dividing potential drop node of described bleeder circuit connects the control end of first switch element, the switch ways of described first switch element is connected between the control end of described voltage input end and second switch element, and the switch ways of described second switch element is connected between described voltage input end and the voltage output end.
2, the overvoltage crowbar based on single supply power voltage according to claim 1; it is characterized in that: described first switch element is a positive-negative-positive triode; its base stage connects the dividing potential drop node of described bleeder circuit; emitter connects described voltage input end, and collector electrode connects the control end of described second switch element.
3, the overvoltage crowbar based on single supply power voltage according to claim 1; it is characterized in that: described first switch element is a P-channel field-effect transistor (PEFT) pipe; its grid connects the dividing potential drop node of described bleeder circuit; source electrode connects described voltage input end, and drain electrode connects the control end of described second switch element.
4, according to each described overvoltage crowbar in the claim 1 to 3 based on single supply power voltage; it is characterized in that: described second switch element is a P-channel field-effect transistor (PEFT) pipe; its grid connects described first switch element; source electrode connects described voltage input end, and drain electrode connects described voltage output end.
5, according to each described overvoltage crowbar in the claim 1 to 3 based on single supply power voltage; it is characterized in that: described bleeder circuit is formed by connecting by a plurality of divider resistances; dispose the resistance of described divider resistance; make the input voltage of introducing by voltage input end when reaching the emergency exit limit value, described dividing potential drop voltages at nodes just reaches the critical conduction voltage of described first switch element.
6, a kind of electric equipment, comprise adapter, mainboard and be connected adapter and mainboard between overvoltage crowbar; It is characterized in that: in described overvoltage crowbar, comprise voltage input end that links to each other with adapter and the voltage output end that links to each other with the motherboard power supply end; On described voltage input end, be connected with a bleeder circuit, the dividing potential drop node of described bleeder circuit connects the control end of first switch element, the switch ways of described first switch element is connected between the control end of described voltage input end and second switch element, and the switch ways of described second switch element is connected between described voltage input end and the voltage output end.
7, electric equipment according to claim 6, it is characterized in that: described first switch element is a positive-negative-positive triode, its base stage connects the dividing potential drop node of described bleeder circuit, and emitter connects described voltage input end, and collector electrode connects the control end of described second switch element.
8, electric equipment according to claim 6, it is characterized in that: described first switch element is a P-channel field-effect transistor (PEFT) pipe, its grid connects the dividing potential drop node of described bleeder circuit, and source electrode connects described voltage input end, and drain electrode connects the control end of described second switch element.
9, according to each described electric equipment in the claim 6 to 8, it is characterized in that: described second switch element is a P-channel field-effect transistor (PEFT) pipe, its grid connects described first switch element, and source electrode connects described voltage input end, and drain electrode connects described voltage output end.
10, according to each described electric equipment in the claim 6 to 8, it is characterized in that: described bleeder circuit is formed by connecting by a plurality of divider resistances, dispose the resistance of described divider resistance, make the input voltage of introducing by voltage input end when reaching the emergency exit limit value, described dividing potential drop voltages at nodes just reaches the critical conduction voltage of described first switch element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU200820026739XU CN201260063Y (en) | 2008-08-01 | 2008-08-01 | Over-voltage protection circuit based on single power supply voltage and electric appliance device having the circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU200820026739XU CN201260063Y (en) | 2008-08-01 | 2008-08-01 | Over-voltage protection circuit based on single power supply voltage and electric appliance device having the circuit |
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| Publication Number | Publication Date |
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| CN201260063Y true CN201260063Y (en) | 2009-06-17 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNU200820026739XU Expired - Lifetime CN201260063Y (en) | 2008-08-01 | 2008-08-01 | Over-voltage protection circuit based on single power supply voltage and electric appliance device having the circuit |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103970036A (en) * | 2013-01-29 | 2014-08-06 | 产晶积体电路股份有限公司 | Power supply method for actively judging power demand |
| CN106058798A (en) * | 2016-05-30 | 2016-10-26 | 安徽华米信息科技有限公司 | Voltage protection device, method and wearable device |
| CN106154021A (en) * | 2015-04-23 | 2016-11-23 | 鸿富锦精密工业(武汉)有限公司 | Voltage alarm system |
| CN106786466A (en) * | 2017-02-13 | 2017-05-31 | 深圳市沃特沃德股份有限公司 | A kind of power supply overvoltage protection circuit, power module and mobile terminal |
| WO2019134625A1 (en) * | 2018-01-03 | 2019-07-11 | 中兴通讯股份有限公司 | Fence circuit for mobile device and mobile device |
| CN111313364A (en) * | 2019-11-29 | 2020-06-19 | 南通同洲电子有限责任公司 | Overvoltage protection device and overvoltage protection method |
-
2008
- 2008-08-01 CN CNU200820026739XU patent/CN201260063Y/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103970036A (en) * | 2013-01-29 | 2014-08-06 | 产晶积体电路股份有限公司 | Power supply method for actively judging power demand |
| CN103970036B (en) * | 2013-01-29 | 2016-11-23 | 产晶积体电路股份有限公司 | Actively differentiate the method for supplying power to of need for electricity |
| CN106154021A (en) * | 2015-04-23 | 2016-11-23 | 鸿富锦精密工业(武汉)有限公司 | Voltage alarm system |
| CN106058798A (en) * | 2016-05-30 | 2016-10-26 | 安徽华米信息科技有限公司 | Voltage protection device, method and wearable device |
| CN106058798B (en) * | 2016-05-30 | 2019-03-15 | 安徽华米信息科技有限公司 | Voltage protection, method and wearable device |
| CN106786466A (en) * | 2017-02-13 | 2017-05-31 | 深圳市沃特沃德股份有限公司 | A kind of power supply overvoltage protection circuit, power module and mobile terminal |
| CN106786466B (en) * | 2017-02-13 | 2019-04-05 | 深圳市沃特沃德股份有限公司 | A kind of power supply overvoltage protection circuit, power module and mobile terminal |
| WO2019134625A1 (en) * | 2018-01-03 | 2019-07-11 | 中兴通讯股份有限公司 | Fence circuit for mobile device and mobile device |
| CN111313364A (en) * | 2019-11-29 | 2020-06-19 | 南通同洲电子有限责任公司 | Overvoltage protection device and overvoltage protection method |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20090617 |
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| CX01 | Expiry of patent term |