CN104124663A - Voltage protection circuit - Google Patents
Voltage protection circuit Download PDFInfo
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- CN104124663A CN104124663A CN201310155049.XA CN201310155049A CN104124663A CN 104124663 A CN104124663 A CN 104124663A CN 201310155049 A CN201310155049 A CN 201310155049A CN 104124663 A CN104124663 A CN 104124663A
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- electronic switch
- voltage
- resistance
- comparator
- voltage source
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Abstract
A voltage protection circuit comprises a comparator, a first electronic switch, a second electronic switch, a first resistor, a second resistor, a third resistor and a fourth resistor. Voltage dividing is performed on a first voltage source by the first resistor and the second resistor and then the first voltage source is transmitted to an in-phase input terminal of the comparator. The voltage dividing is performed on a second voltage source by the third resistor and the fourth resistor and then the second voltage source is transmitted to an inverting input terminal of the comparator. When the first voltage source is in a normal range, a voltage of the in-phase input terminal of the comparator is less than a voltage of the inverting input terminal, a first electronic switch is closed and a second electronic switch is conducted, and the first voltage source outputs a working voltage to the voltage protection circuit through the second electronic switch. When the first voltage source exceeds an upper limit value of a normal work voltage, the voltage of the in-phase input terminal of the comparator is greater than the voltage of the inverting input terminal, the first electronic switch is conducted, the second electronic switch is closed, and the first voltage source stops outputting the voltage to the voltage protection circuit.
Description
Technical field
The present invention relates to a kind of voltage protection circuit.
Background technology
On computer main board, each parts all have the voltage range of its steady operation, just there will be operation irregularity if exceed this voltage range, damage even electronic component.
Summary of the invention
In view of above content, be necessary to provide a kind of voltage protection circuit, in the time that exceeding normal value, voltage automatically stops power supply, to prevent that electronic component is damaged.
A kind of voltage protection circuit, be connected between a voltage conversion circuit and one first voltage source, in order to the normal voltage value of described the first voltage source is offered to described voltage conversion circuit, described voltage protection circuit comprises comparator, the first electronic switch, the second electronic switch and the first to the 5th resistance, one end of described the first resistance is connected with described the first voltage source, the other end is by the second grounding through resistance, one end of described the 3rd resistance is connected with a second voltage source, the other end is by the 4th grounding through resistance, node between described the first resistance and the second resistance is connected with the in-phase input end of described comparator, to provide the first input voltage to the in-phase input end of comparator, node between described the 3rd resistance and the 4th resistance is connected with the inverting input of described comparator, to provide the second input voltage to the inverting input of comparator, the first end of described the first electronic switch is connected with the output of described comparator, the second end of described the first electronic switch is connected with described second voltage source, the 3rd end ground connection of described the first electronic switch, the first end of described the second electronic switch is connected with the second end of the first electronic switch by the 5th resistance, the second end of described the second electronic switch is connected with the first voltage source, the 3rd end of described the second electronic switch is connected with described voltage conversion circuit, when the first voltage source is during in normal range of operation, described the first input voltage is less than the second input voltage, described comparator is exported the first end of low level signal to the first electronic switch, the first electronic switch cut-off, the first end of the second electronic switch receives a high level signal, the second electronic switch conducting, described the first voltage source passes through the second electronic switch to voltage protection circuit output voltage, in the time that the first voltage source exceeds the higher limit of normal working voltage, described the first input voltage is greater than the second input voltage, described comparator is exported the first end of high level signal to the first electronic switch, the first electronic switch conducting, the first end of the second electronic switch receives a low level signal, the second electronic switch cut-off, described the first voltage source stops to voltage protection circuit output voltage.
Above-mentioned voltage protection circuit compares the size of the first input voltage and the second input voltage by comparator, and then, the Voltage-output of the first voltage source, to voltage conversion circuit, is powered during in normal range (NR) at the magnitude of voltage of the first voltage source; In the time that the magnitude of voltage of the first voltage source exceeds the higher limit of normal working voltage, voltage protection circuit control the first voltage source stops powering to voltage conversion circuit.
Brief description of the drawings
Fig. 1 is the circuit diagram of the preferred embodiments of voltage protection circuit of the present invention.
Main element symbol description
| Voltage protection circuit | 10 |
| Voltage conversion circuit | 20 |
| Voltage source | Vin、VCC |
| The first electronic switch | Q1 |
| The first electronic switch | Q2 |
| Comparator | U1 |
| The first resistance | R1 |
| The second resistance | R2 |
| The 3rd resistance | R3 |
| The 4th resistance | R4 |
| The 5th resistance | R5 |
| The 6th resistance | R6 |
Following embodiment further illustrates the present invention in connection with above-mentioned accompanying drawing.
Embodiment
Below in conjunction with accompanying drawing and preferred embodiments, the present invention is described in further detail:
Please refer to Fig. 1, voltage protection circuit 10 of the present invention is connected with a voltage conversion circuit 20 and a voltage source vin,, the Voltage-output of voltage source vin, to voltage conversion circuit 20, is powered when the normal range (NR) in order to the output voltage in voltage source vin.
Described voltage protection circuit 10 comprises comparator U1, the first electronic switch Q1, the second electronic switch Q2 and the first resistance to the six resistance R 1-R6.One end of described the first resistance R 1 is connected with described voltage source vin, and the other end of resistance the one R1 is by the second resistance R 2 ground connection.One end of described the 3rd resistance R 3 is connected with a voltage source Vcc 1, and the other end of the 3rd resistance R 3 is by the 4th resistance R 4 ground connection.Node between described the first resistance R 1 and the second resistance R 2 is connected with the in-phase input end of described comparator U1, so that the first input voltage V1 to be provided to the in-phase input end of comparator U1.Node between described the 3rd resistance R 3 and the 4th resistance R 4 is connected with the inverting input of described comparator U1, so that the second input voltage V2 to be provided to the inverting input of comparator U1.The first end of described the first electronic switch Q1 is connected with the output of described comparator U1, and the second end of described the first electronic switch Q1 is connected with described voltage source V CC1, and the 3rd end of described the first electronic switch Q1 is by described the 5th resistance R 5 ground connection.The first end of described the second electronic switch Q2 is connected with the second end of the first electronic switch Q1 by described the 6th resistance R 6, the second end of described the second electronic switch Q2 is connected with described voltage source vin, and the 3rd end of described the second electronic switch Q2 is connected with described voltage conversion circuit 20.。The voltage end of described comparator U1 connects described voltage source Vcc 1.
In the present embodiment, the first electronic switch Q1, the second electronic switch Q2 are NMOS field effect transistor, the first end of described the first electronic switch Q1, the second electronic switch Q2, the second end, the 3rd end grid, drain electrode, the source electrode of corresponding NMOS field effect transistor respectively.Certainly, the first electronic switch Q1, the second electronic switch Q2 can be also NPN triode, and the first end of described the first electronic switch Q1, the second electronic switch Q2, the second end, the 3rd end are respectively base stage, emitter, the collector electrode of NPN triode.Below the operation principle to above-mentioned voltage protection circuit is described:
In work, by the resistance value of regulating resistance R1-R4, according to magnitude of voltage=Vin/ (R1+R2) * R2 of the first input voltage V1 of the in-phase input end of comparator U1, magnitude of voltage=Vcc/ (R3+R4) * R4 of the second input voltage V2 of the inverting input of comparator U1, make voltage source vin in the time of normal range (NR), the first input voltage V1 is less than the second input voltage V2; When voltage source vin exceeds the higher limit of normal working voltage, the first input voltage V1 is greater than the second input voltage V2.
When voltage source vin is during in normal range (NR), the first input voltage V1 of voltage source vin after the first resistance R 1 and the second resistance R 2 dividing potential drops offers the in-phase input end of comparator U1, the second input voltage V2 of voltage source V CC after the 3rd resistance R 3 and the 4th resistance R 4 dividing potential drops offers the inverting input of comparator U1, because the first input voltage V1 is less than the second input voltage V2, therefore the output of comparator U1 is exported a low level signal, the grid of the first electronic switch Q1 receives the low level signal of described comparator U1 output, the first electronic switch Q1 cut-off, the drain electrode of the first electronic switch Q1 is high level.The grid of the second electronic switch Q2 receives high level signal, the second electronic switch Q2 conducting.Now, voltage source vin just can, by the second electronic switch Q2 output voltage to described voltage conversion circuit 20, think that voltage conversion circuit 20 provides normal operating voltage.
In the time that voltage source vin exceeds the higher limit of normal working voltage, the first input voltage V1 of voltage source vin after the first resistance R 1 and the second resistance R 2 dividing potential drops offers the in-phase input end of comparator U1, the second input voltage V2 of voltage source Vcc 1 after the 3rd resistance R 3 and the 4th resistance R 4 dividing potential drops offers the inverting input of comparator U1, because the first input voltage V1 is greater than the second input voltage V2, therefore the output of comparator U1 is exported a high level signal, the grid of the first electronic switch Q1 receives the high level signal of described comparator U1 output, the first electronic switch Q1 conducting, the drain electrode of the first electronic switch Q1 is low level.The grid of the second electronic switch Q2 receives the low level signal that the drain electrode of the first electronic switch Q1 is sent, the second electronic switch Q2 cut-off.Now, voltage source vin stops to described voltage conversion circuit 20 output services voltages, to avoid burning the electronic component of voltage conversion circuit 20 inside.
Claims (4)
1. a voltage protection circuit, be connected between a voltage conversion circuit and one first voltage source, , described voltage protection circuit comprises comparator, the first electronic switch, the second electronic switch and the first to the 5th resistance, one end of described the first resistance is connected with described the first voltage source, the other end is by the second grounding through resistance, one end of described the 3rd resistance is connected with a second voltage source, the other end is by the 4th grounding through resistance, node between described the first resistance and the second resistance is connected with the in-phase input end of described comparator, to provide the first input voltage to the in-phase input end of comparator, node between described the 3rd resistance and the 4th resistance is connected with the inverting input of described comparator, to provide the second input voltage to the inverting input of comparator, the first end of described the first electronic switch is connected with the output of described comparator, the second end of described the first electronic switch is connected with described second voltage source, the 3rd end ground connection of described the first electronic switch, the first end of described the second electronic switch is connected with the second end of the first electronic switch by the 5th resistance, the second end of described the second electronic switch is connected with the first voltage source, the 3rd end of described the second electronic switch is connected with described voltage conversion circuit, when the first voltage source is during in normal range of operation, described the first input voltage is less than the second input voltage, described comparator is exported the first end of low level signal to the first electronic switch, the first electronic switch cut-off, the first end of the second electronic switch receives a high level signal, the second electronic switch conducting, described the first voltage source passes through the second electronic switch to voltage conversion circuit output voltage, in the time that the first voltage source exceeds the higher limit of normal working voltage, described the first input voltage is greater than the second input voltage, described comparator is exported the first end of high level signal to the first electronic switch, the first electronic switch conducting, the first end of the second electronic switch receives a low level signal, the second electronic switch cut-off, described the first voltage source stops to voltage conversion circuit output voltage.
2. voltage protection circuit as claimed in claim 1, is characterized in that: described voltage protection circuit also comprises the 6th resistance, and the 3rd end of described the first electronic switch is by the 6th grounding through resistance.
3. voltage protection circuit as claimed in claim 2; it is characterized in that: described the first electronic switch, the second electronic switch are NMOS field effect transistor, the first end of described the first electronic switch, the second electronic switch, the second end, the 3rd end are respectively grid, drain electrode, the source electrode of NMOS field effect transistor.
4. voltage protection circuit as claimed in claim 2; it is characterized in that: described the first electronic switch, the second electronic switch are NPN triode, the first end of described the first electronic switch, the second electronic switch, the second end, the 3rd end are respectively base stage, emitter, the collector electrode of NPN triode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310155049.XA CN104124663A (en) | 2013-04-29 | 2013-04-29 | Voltage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310155049.XA CN104124663A (en) | 2013-04-29 | 2013-04-29 | Voltage protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104124663A true CN104124663A (en) | 2014-10-29 |
Family
ID=51769981
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310155049.XA Pending CN104124663A (en) | 2013-04-29 | 2013-04-29 | Voltage protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104124663A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108462154A (en) * | 2018-03-23 | 2018-08-28 | 高湍斌 | Power switch circuit |
| CN108494257A (en) * | 2018-03-23 | 2018-09-04 | 高湍斌 | Power circuit with output regulatory function |
-
2013
- 2013-04-29 CN CN201310155049.XA patent/CN104124663A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108462154A (en) * | 2018-03-23 | 2018-08-28 | 高湍斌 | Power switch circuit |
| CN108494257A (en) * | 2018-03-23 | 2018-09-04 | 高湍斌 | Power circuit with output regulatory function |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20141029 |