CN103944140A - Alternating current input over-voltage protection circuit - Google Patents
Alternating current input over-voltage protection circuit Download PDFInfo
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- CN103944140A CN103944140A CN201410078392.3A CN201410078392A CN103944140A CN 103944140 A CN103944140 A CN 103944140A CN 201410078392 A CN201410078392 A CN 201410078392A CN 103944140 A CN103944140 A CN 103944140A
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Abstract
The invention provides an alternating current input over-voltage protection circuit. The alternating current input over-voltage protection circuit comprises an alternating current isolation detection unit, an absolute value amplifying unit, a peak voltage sampling unit and an over-voltage return difference unit, wherein the alternating current isolation detection unit converts received power voltage signals of an alternating current input unit to be low voltage signals and then transmits the low voltage signals to the absolute value amplifying unit; the absolute value amplifying unit changes the low voltage signals into absolute values, amplifies the absolute values and outputs the absolute values to the peak voltage sampling unit; the peak voltage sampling unit selects the peak voltage from the amplified voltage signals and outputs the peak voltage to the over-voltage return difference unit; the over-voltage return difference unit compares the peak voltage with preset voltage and outputs a level signal. As the over-voltage return difference unit is additionally arranged in the alternating current input over-voltage protection circuit, the protection circuit does not act repeatedly even when the voltage fluctuates, and a power source operates reliably.
Description
Technical field
The present invention relates to a kind of overvoltage crowbar that exchanges, particularly relate to a kind of single phase alternating current (A.C.) voltage protection circuit against input over-voltage.Background technology
Overvoltage crowbar is a kind of Important Circuit for the protection of power supply, in the time that input voltage exceeds the trouble free service voltage of power supply, and overvoltage circuit action, not damaged to ensure power supply.Current protective circuit, has protective circuit perseveration often; Meanwhile, after AC-input voltage is recovered normally, circuit is automatic recovery of power supply timely, affects the timely power supply of power supply.
Summary of the invention
The shortcoming of prior art in view of the above; the object of the present invention is to provide a kind of protection circuit against input over-voltage that exchanges, have perseveration and recover the normal rear circuit problem of automatic recovery of power supply timely in AC-input voltage for solving overvoltage crowbar of the prior art.
For achieving the above object and other relevant objects, the invention provides following technical scheme:
A kind of protection circuit against input over-voltage that exchanges, comprising: exchange isolation detection unit, after receiving power supply voltage signal and power supply voltage signal is changed into low voltage signal, exported, described low-voltage comprises the first low voltage signal and the second low voltage signal, absolute value amplifying unit, connect described interchange isolation detection unit and receive described low voltage signal, come optionally the voltage difference between described the first low voltage signal and the second low voltage signal is amplified and exported for the voltage difference between the first low voltage signal and the second low voltage signal exported according to low voltage signal: if described the first low voltage signal is greater than the second low voltage signal, described absolute value amplifying unit gives the poor amplifying signal of output voltage after the voltage difference between described the first low voltage signal and the second low voltage signal is amplified, if or described the first low voltage signal is less than the second low voltage signal, described absolute value amplifying unit gives the poor amplifying signal of output voltage after the voltage difference between described the first low voltage signal and the second low voltage signal is amplified, crest voltage sampling unit, connects described absolute value amplifying unit, in order to receive described voltage difference amplifying signal and described voltage difference amplifying signal to be obtained to the crest voltage of described voltage difference amplifying signal as crest voltage collection, overvoltage return difference unit, is connected in described crest voltage sampling unit and a predeterminated voltage is provided, and for receiving described crest voltage and described crest voltage and described predeterminated voltage being compared, and then exports high or low level signal according to comparative result.
In interchange protection circuit against input over-voltage provided by the invention; described absolute value amplifying unit amplifies and is specially voltage difference between described the first low voltage signal and the second low voltage signal: described the first low voltage signal and the second low voltage signal are connected in two amplifier elements on the contrary, utilize described two amplifier elements to amplify output to voltage difference between the first low voltage signal and the second low voltage signal.
In interchange protection circuit against input over-voltage provided by the invention; also comprise AC input cell; be connected in mains supply and the described isolation detection unit that exchanges; in order to flowing to described interchange isolation detection unit after described mains supply current limliting; wherein; described AC input cell is made up of a current-limiting resistance R1, and described resistance R 1 is series on arbitrary voltage end of described mains supply.
In interchange protection circuit against input over-voltage provided by the invention; described interchange isolation detection unit is by resistance R 2; resistance R 4; resistance R 5 and voltage transformer composition; wherein; the input of described voltage transformer connects described AC input cell or mains voltage; the output of described voltage transformer is in parallel with described resistance R 2 two ends; ground connection after the first end of described resistance R 4 is connected with the first end of resistance R 5, the second end of described resistance R 4 and the second end of resistance R 5 are in parallel with described resistance R 2 two ends.
In interchange protection circuit against input over-voltage provided by the invention, described absolute value amplifying unit is by resistance R 6, resistance R 7, resistance R 8, resistance R 10, resistance R 11, resistance R 12, resistance R 13, resistance R 14, capacitor C 1, diode D1A, diode D1B, diode D2A, diode D2B, and operational amplifier U1A and operational amplifier U1B composition, wherein, the first end of described resistance R 6 connects the first end of described resistance R 11 and the positive input terminal of described operational amplifier U1A, the second end ground connection of described resistance R 11, the first end of described resistance R 7 connects the negative input end of described operational amplifier U1A and the first end of described resistance R 12, the first end of described resistance R 8 connects the positive input terminal of described operational amplifier U1B and the first end of resistance R 13, the second end that the second end of described resistance R 8 connects the second end of described resistance R 7 and the second end of described resistance R 8 and described resistance R 7 is connected the second end of the resistance R 5 in described interchange isolation detection unit simultaneously, the second end ground connection of described resistance R 13, the second end that the first end of described resistance R 10 connects the second end of described resistance R 6 and the first end of described resistance R 10 and described resistance R 6 is connected the second end of the resistance R 4 in described interchange isolation detection unit simultaneously, the second end of described resistance R 10 connects the negative input end of described operational amplifier U1B and the first end of described resistance R 14, the output of described operational amplifier U1A connects the positive pole of described diode D1A and diode D1B, the output of described operational amplifier U1B connects the positive pole of described diode D2A and diode D2B, the second end of described resistance R 12 is connected with the negative pole of described diode D1A and the negative pole of described diode D2B respectively with the second end of described resistance R 14, the negative pole of described diode D2A is connected with the negative pole of diode D1B, the first end of described capacitor C 1 connects the positive pole of described operational amplifier U1A working power, the second end ground connection of described capacitor C 1.
In interchange protection circuit against input over-voltage provided by the invention; described crest voltage sampling unit is made up of resistance R 15 electric capacity R3 and resistance R 16; wherein; described resistance 15 first ends connect the first end of described capacitor C 3 and the first end of described resistance R 16; the second end of described resistance 15 connects the negative pole of described diode D2A negative pole/diode D1B, while ground connection after the second end of described capacitor C 3 is connected with described resistance R 16.
In interchange protection circuit against input over-voltage provided by the invention, described overvoltage return difference unit is by resistance R 3, resistance R 9, resistance R 17, resistance R 18, comparator U2, capacitor C 2 and voltage-stabiliser tube Z1, wherein, the first termination one predeterminated voltage of described resistance R 9, the first end of described resistance R 17 connects the first end of the described resistance R 15 in described crest voltage sampling unit, the second end of described resistance R 9 is connected with positive input terminal and the negative input end of described comparator U2 respectively with the second end of described resistance R 17, described comparator U2 output connects the first end of described resistance R 3, the second end of described resistance R 3 connects the positive pole of described voltage-stabiliser tube Z1 and the first end of described resistance R 18, the second end of described resistance R 18 connects the second end of described resistance R 9, the minus earth of described voltage-stabiliser tube Z1.
Technical scheme as mentioned above, prior art interchange protection circuit against input over-voltage provided by the invention is simple in structure relatively, and detection speed is fast, and circuit is reliable; And there is over-voltage protecting function in the time of quiescent imput voltage and the dynamic over-voltage protecting function of any input voltage uphill process; in addition; the setting of return difference resistance R 18; avoid near output signal mistake pressure point to vibrate back and forth; simultaneously; the setting of discharge resistance (resistance R 16), when input voltage is during lower than set point, can cancel rapidly overvoltage protection signal automatically.
Brief description of the drawings
Fig. 1 is shown as the present invention and exchanges the circuit theory schematic diagram of protection circuit against input over-voltage.
Fig. 2 is shown as the present invention and exchanges protection circuit against input over-voltage and exchange in one embodiment the circuit structure diagram of isolation detection unit.
Fig. 3 is shown as the present invention and exchanges the protection circuit against input over-voltage circuit structure diagram of absolute value amplifying unit in one embodiment.
Fig. 4 is shown as the present invention and exchanges the protection circuit against input over-voltage circuit structure diagram of crest voltage sampling unit in one embodiment.
Fig. 5 is shown as the present invention and exchanges the circuit structure diagram of protection circuit against input over-voltage overvoltage return difference in one embodiment unit.
Fig. 6 is shown as the present invention and exchanges the protection circuit against input over-voltage circuit structure diagram of AC input cell in one embodiment.
Fig. 7 is shown as the present invention and exchanges protection circuit against input over-voltage integrated circuit structure chart in one embodiment.
Drawing reference numeral explanation
1 power supply
2 exchange protection circuit against input over-voltage
20 AC input cell
21 exchange isolation detection unit
211 first low voltage signals
212 second low voltage signals
22 absolute value amplifying units
23 crest voltage sampling units
231 discharge resistances
24 overvoltage return difference unit
241 resistance R 9
242 resistance R 18
243 voltage-stabiliser tube Z1
3 level signals
Embodiment
Below, by specific instantiation explanation embodiments of the present invention, those skilled in the art can understand other advantages of the present invention and effect easily by the disclosed content of this specification.The present invention can also be implemented or be applied by other different embodiment, and the every details in this specification also can be based on different viewpoints and application, carries out various modifications or change not deviating under spirit of the present invention.It should be noted that, in the situation that not conflicting, the feature in following examples and embodiment can combine mutually.
Refer to Fig. 1 to Fig. 7, it should be noted that, the diagram providing in following examples only illustrates basic conception of the present invention in a schematic way, satisfy and only show with assembly relevant in the present invention in graphic but not component count, shape and size drafting while implementing according to reality, when its actual enforcement, kenel, quantity and the ratio of each assembly can be a kind of random change, and its assembly layout kenel also may be more complicated.
Exchanging input overvoltage protection is to power supply important protection, and in the time that input voltage exceeds the trouble free service voltage of power supply, this circuit operation, has ensured that power supply is not damaged.Current protective circuit, owing to lacking the setting of return difference, often has protective circuit perseveration, and meanwhile, after AC-input voltage is recovered normally, circuit is automatic recovery of power supply timely, affects the timely power supply of power supply.The present invention, by added overvoltage return difference unit 24 in interchange protection circuit against input over-voltage 2, makes circuit can, because action repeatedly appears in voltage fluctuation, not ensure the reliability service of power supply, and details are as follows for its concrete scheme.
See Fig. 1, show the circuit theory schematic diagram that the present invention exchanges protection circuit against input over-voltage, from figure, the invention provides a kind of protection circuit against input over-voltage 2 that exchanges, comprise and exchange isolation detection unit 21, absolute value amplifying unit 22, crest voltage sampling unit 23 and overvoltage return difference unit 24, wherein, described interchange isolation detection unit 21 is exported after receiving power supply 1 voltage signal and power supply 1 voltage signal is changed into low voltage signal, and described low-voltage is made up of the first low voltage signal 211 and the second low voltage signal 212, described absolute value amplifying unit 22 connects described interchange isolation detection unit 21 and receives described low voltage signal, come optionally the voltage difference between described the first low voltage signal 211 and the second low voltage signal 212 is amplified and exported for the voltage difference between the first low voltage signal 211 and the second low voltage signal 212 exported according to low voltage signal: if described the first low voltage signal 211 is greater than the second low voltage signal 212, described absolute value amplifying unit 22 gives the poor amplifying signal of output voltage after the voltage difference between described the first low voltage signal and the second low voltage signal 212 is amplified, if or described the first low voltage signal is less than the second low voltage signal 212, described absolute value amplifying unit 22 gives the poor amplifying signal of output voltage to described after the voltage difference between described the first low voltage signal and the second low voltage signal 212 is amplified, crest voltage sampling unit 23, connects described absolute value amplifying unit 22, in order to receive described voltage difference amplifying signal and described voltage difference amplifying signal to be obtained to the crest voltage of described voltage difference amplifying signal as crest voltage collection, described overvoltage return difference unit 24 is connected in described crest voltage sampling unit 23 and a predeterminated voltage is provided, and for receiving described crest voltage and described crest voltage and described predeterminated voltage being compared, and then exports high or low level signal 3 according to comparative result.Wherein, described absolute value amplifying unit 22 amplifies and is specially voltage difference between described the first low voltage signal 211 and the second low voltage signal 212: described the first low voltage signal 211 and the second low voltage signal 212 are connected in two amplifier elements on the contrary, utilize described two amplifier elements to amplify output to voltage difference between the first low voltage signal 211 and the second low voltage signal 212.
In order to understand in further detail principle of the present invention and detailed technology scheme, by a physical circuit figure of described interchange protection circuit against input over-voltage 2 is provided, technical scheme of the present invention is illustrated here.
Particularly, see Fig. 2, show the circuit structure diagram that the present invention exchanges protection circuit against input over-voltage and exchange in one embodiment isolation detection unit, in interchange protection circuit against input over-voltage 2 provided by the invention, described interchange isolation detection unit 21 is by resistance R 2, resistance R 4, resistance R 5 and voltage transformer composition, wherein, the input of described voltage transformer connects described AC input cell or mains voltage, the output of described voltage transformer is in parallel with described resistance R 2 two ends, ground connection after the first end of described resistance R 4 is connected with the first end of resistance R 5, the second end of described resistance R 4 and the second end of resistance R 5 are in parallel with described resistance R 2 two ends.
Particularly, see Fig. 3, show the present invention and exchange the protection circuit against input over-voltage circuit structure diagram of absolute value amplifying unit 22 in one embodiment, in interchange protection circuit against input over-voltage 2 provided by the invention, described absolute value amplifying unit 22 is by resistance R 6, resistance R 7, resistance R 8, resistance R 10, resistance R 11, resistance R 12, resistance R 13, resistance R 14, capacitor C 1, diode D1A, diode D1B, diode D2A, diode D2B, and operational amplifier U1A and operational amplifier U1B composition, wherein, the first end of described resistance R 6 connects the first end of described resistance R 11 and the positive input terminal of described operational amplifier U1A, the second end ground connection of described resistance R 11, the first end of described resistance R 7 connects the negative input end of described operational amplifier U1A and the first end of described resistance R 12, the first end of described resistance R 8 connects the positive input terminal of described operational amplifier U1B and the first end of resistance R 13, the second end that the second end of described resistance R 8 connects the second end of described resistance R 7 and the second end of described resistance R 8 and described resistance R 7 is connected the second end of the resistance R 5 in described interchange isolation detection unit 21 simultaneously, the second end ground connection of described resistance R 13, the second end that the first end of described resistance R 10 connects the second end of described resistance R 6 and the first end of described resistance R 10 and described resistance R 6 is connected the second end of the resistance R 4 in described interchange isolation detection unit 21 simultaneously, the second end of described resistance R 10 connects the negative input end of described operational amplifier U1B and the first end of described resistance R 14, the output of described operational amplifier U1A connects the positive pole of described diode D1A and diode D1B, the output of described operational amplifier U1B connects the positive pole of described diode D2A and diode D2B, the second end of described resistance R 12 is connected with the negative pole of described diode D1A and the negative pole of described diode D2B respectively with the second end of described resistance R 14, the negative pole of described diode D2A is connected with the negative pole of diode D1B, the first end of described capacitor C 1 connects the positive pole of described operational amplifier U1A working power, the second end ground connection of described capacitor C 1.
Particularly, see Fig. 4, show the present invention and exchange the protection circuit against input over-voltage circuit structure diagram of crest voltage sampling unit in one embodiment, in interchange protection circuit against input over-voltage 2 provided by the invention, described crest voltage sampling unit 23 is made up of resistance R 15 electric capacity R3 and resistance R 16, wherein, described resistance 15 first ends connect the first end of described capacitor C 3 and the first end of described resistance R 16, the second end of described resistance 15 connects the negative pole of described diode D2A negative pole/diode D1B, while ground connection after the second end of described capacitor C 3 is connected with described resistance R 16.
Particularly, see Fig. 5, show the circuit structure diagram that the present invention exchanges protection circuit against input over-voltage overvoltage return difference in one embodiment unit, in interchange protection circuit against input over-voltage 2 provided by the invention, described overvoltage return difference unit 24 is by resistance R 3, resistance R 9241, resistance R 17, resistance R 18242, comparator U2, capacitor C 2 and voltage-stabiliser tube Z1243, wherein, the first termination one predeterminated voltage of described resistance R 9241, the first end of described resistance R 17 connects the first end of the described resistance R 15 in described crest voltage sampling unit 23, the second end of described resistance R 9241 is connected with positive input terminal and the negative input end of described comparator U2 respectively with the second end of described resistance R 17, described comparator U2 output connects the first end of described resistance R 3, the second end of described resistance R 3 connects the positive pole of described voltage-stabiliser tube Z1243 and the first end of described resistance R 18242, the second end of described resistance R 18242 connects the second end of described resistance R 9241, the minus earth of described voltage-stabiliser tube Z1243.
In addition; the above exchanges in protection circuit against input over-voltage 2 can also comprise AC input cell 20; see Fig. 6; show the present invention and exchange the protection circuit against input over-voltage circuit structure diagram of AC input cell in one embodiment; described AC input cell 20 is connected in mains supply 1 and the described isolation detection unit 21 that exchanges; in order to flowing to described interchange isolation detection unit 21 after described mains supply 1 current limliting; wherein; described AC input cell 20 is made up of a current-limiting resistance R1, and described resistance R 1 is series on arbitrary voltage end of described mains supply 1.
Further, exchange protection circuit against input over-voltage 2 in order to make those skilled in the art can understand better the above, now set forth from the angle of described circuit operation logic again.
See Fig. 7, show the present invention and exchange protection circuit against input over-voltage integrated circuit structure chart in one embodiment, wherein, in the drawings using voltage U1 on VJC1 line as the first low-voltage, and using voltage U2 on VCJ2 line as the second low-voltage, operation principle of the present invention is as follows: AC-input voltage passes the signal to the other end by exchanging the voltage transformer pt 1 of isolation detection unit 21 after by resistance R 1 current limliting, by resistance R 2, electric current is changed into low voltage signal, in absolute value amplifying unit 22, by accessing from exchanging being positioned at the voltage U 1 on VJC1 line and being positioned at the voltage U 2 on VCJ2 line in isolation detection unit 21, if voltage U1 is greater than voltage U2 on VCJ2 line on VJC1 line, operational amplifier U1A amplifies the voltage difference of the first low voltage signal 211 and the second low voltage signal 212, operational amplifier U1A is just output as, double diode D1 conducting, signal after amplifying is passed to peak value sampling unit, operational amplifier U1B amplifies the voltage difference of the first low voltage signal 211 and the second low voltage signal 212, operational amplifier U1B is output as negative, double diode D2 cut-off, if voltage U1 is less than voltage U2 on VCJ2 line on VJC1 line, operational amplifier U1A amplifies the voltage difference of the first low voltage signal 211 and the second low voltage signal 212, U1A is output as negative, double diode D1 cut-off, operational amplifier U1B amplifies the voltage difference of the first low voltage signal 211 and the second low voltage signal 212, operational amplifier U1B is just output as, and the voltage difference amplifying signal obtaining after amplifying is passed to peak value sampling unit by double diode D2 conducting, in crest voltage sampling unit 23, the voltage difference amplifying signal after amplifying discharges and recharges capacitor C 3 and resistance R 16 after by resistance R 15 current limlitings, flows to overvoltage return difference unit 24.Now, in the time that the voltage of the inverting input V-of comparator U2 exceedes the default high voltage V+ of comparator U2 normal phase input end, the output output low level of comparator U2; When the voltage of the inverting input V-of comparator U2 is during lower than the default low voltage V+ of comparator U2 normal phase input end, the output output high level of comparator U2; The default high voltage V+ of normal phase input end of comparator U2 is called high threshold voltage, the default low voltage V+ of normal phase input end of comparator U2 is called low threshold voltage, both differences are overvoltage return difference, and return difference value is determined by resistance R 9241, resistance R 18242 and voltage-stabiliser tube Z1243; The setting of R16, is conducive to after electric voltage over press, drops in the process of normal value, allows detection voltage follow in time variation.
More simply, be also that described alternating voltage isolation detection unit converts the AC input cell receiving 20 to low-voltage and passes to absolute value amplifying unit 22; Absolute value amplifying unit 22 carries out voltage difference by low voltage signal and amplifies the rear poor amplifying signal of output voltage of processing to peak value sampling unit; Peak value sampling unit is got peak value by described voltage difference amplifying signal and is exported to overvoltage return difference unit 24; Overvoltage return difference unit 24 compares crest voltage and predeterminated voltage, and exports high or low level signal (for example,, if crest voltage is greater than predeterminated voltage output low level, if crest voltage is less than predeterminated voltage output high level) according to comparative result.Generally; described interchange protection circuit against input over-voltage 2 provided by the invention is simple in structure, and detection speed is fast, and circuit is reliable; there is over-voltage protecting function in the time of quiescent imput voltage and the dynamic over-voltage protecting function of any input voltage uphill process; wherein, the setting of return difference resistance R 18, has avoided near output signal mistake pressure point to vibrate back and forth; simultaneously; discharge resistance 231(is resistance R 16) setting, when input voltage is during lower than set point, can automatically cancel rapidly overvoltage protection signal.
In sum, the present invention, by added overvoltage return difference unit 24 in interchange protection circuit against input over-voltage 2, makes protective circuit not because action repeatedly appears in voltage fluctuation, has ensured the reliability service of power supply.So the present invention has effectively overcome various shortcoming of the prior art and tool high industrial utilization.
Above-described embodiment is illustrative principle of the present invention and effect thereof only, but not for limiting the present invention.Any person skilled in the art scholar all can, under spirit of the present invention and category, modify or change above-described embodiment.Therefore, such as in affiliated technical field, have and conventionally know that the knowledgeable, not departing from all equivalence modifications that complete under disclosed spirit and technological thought or changing, must be contained by claim of the present invention.
Claims (8)
1. exchange a protection circuit against input over-voltage, it is characterized in that, at least comprise:
Exchange isolation detection unit, after receiving power supply voltage signal and power supply voltage signal is changed into low voltage signal, give
With output, described low voltage signal comprises the first low voltage signal and the second low voltage signal;
Absolute value amplifying unit, connects described interchange isolation detection unit and receives described low voltage signal, for according to low electricity
Press voltage difference between the first low voltage signal and the second low voltage signal of exporting in signal to come optionally described the
Voltage difference between one low voltage signal and the second low voltage signal is amplified and exports:
If described the first low voltage signal is greater than the second low voltage signal, described absolute value amplifying unit is to described the first low electricity
Voltage difference between pressure signal and the second low voltage signal gives the poor amplifying signal of output voltage after amplifying, or
If described the first low voltage signal is less than the second low voltage signal, described absolute value amplifying unit is to described the first low electricity
Voltage difference between pressure signal and the second low voltage signal gives the poor amplifying signal of output voltage after amplifying;
Crest voltage sampling unit, connects described absolute value amplifying unit, in order to receive described voltage difference amplifying signal and to institute
State voltage difference amplifying signal and obtain the crest voltage of described voltage difference amplifying signal as crest voltage collection;
Overvoltage return difference unit, is connected in described crest voltage sampling unit and a predeterminated voltage is provided, for receiving described peak value
Voltage also compares described crest voltage and described predeterminated voltage, and then exports high or low level letter according to comparative result
Number.
2. interchange protection circuit against input over-voltage according to claim 1, is characterized in that, also comprises AC input cell, connects
Be connected to mains supply and the described isolation detection unit that exchanges, in order to by after described mains supply current limliting, flow to described interchange every
From detecting unit.
3. interchange protection circuit against input over-voltage according to claim 2, is characterized in that, described AC input cell is by a limit
Leakage resistance R1 composition, described resistance R 1 is series on arbitrary voltage end of described mains supply.
4. interchange protection circuit against input over-voltage according to claim 1 and 2, is characterized in that, described absolute value amplifying unit
Voltage difference between described the first low voltage signal and the second low voltage signal is amplified and is specially: by described the first low electricity
Press signal and the second low voltage signal to be connected on the contrary in two amplifier elements, utilize described two amplifier elements to first
Between low voltage signal and the second low voltage signal, voltage difference is amplified output.
5. interchange protection circuit against input over-voltage according to claim 1 and 2, is characterized in that, described interchange isolation detection list
First in resistance R 2, resistance R 4, resistance R 5 and voltage transformer composition, wherein, the input of described voltage transformer
Connect described AC input cell or mains voltage, the output of described voltage transformer and described resistance R 2 two ends
Parallel connection, the first end of described resistance R 4 be connected with the first end of resistance R 5 after ground connection, the second end of described resistance R 4 and
The second end of resistance R 5 is connected in parallel in described resistance R 2 two ends.
6. interchange protection circuit against input over-voltage according to claim 5, is characterized in that: described absolute value amplifying unit is by electricity
Resistance R6, resistance R 7, resistance R 8, resistance R 10, resistance R 11, resistance R 12, resistance R 13, resistance R 14, capacitor C 1, diode
D1A, diode D1B, diode D2A, diode D2B, and operational amplifier U1A and operational amplifier U1B group
Become, wherein, the first end of described resistance R 6 connects the first end of described resistance R 11 and described operational amplifier U1A
Positive input terminal, the second end ground connection of described resistance R 11, the first end of described resistance R 7 connects described operational amplifier U1A
Negative input end and the first end of described resistance R 12, the first end of described resistance R 8 connects described operational amplifier U1B
Positive input terminal and the first end of resistance R 13, the second end of described resistance R 8 connects the second end and the institute of described resistance R 7
State the second end of resistance R 8 and the second end of described resistance R 7 and be connected the resistance R 5 in described interchange isolation detection unit simultaneously
The second end, the second end ground connection of described resistance R 13, the first end of described resistance R 10 connects of described resistance R 6
The second end of the first end of two ends and described resistance R 10 and described resistance R 6 is connected in described interchange isolation detection unit simultaneously
The second end of resistance R 4, the second end of described resistance R 10 connects negative input end and the institute of described operational amplifier U1B
State the first end of resistance R 14, the output of described operational amplifier U1A connects described diode D1A and diode D1B
Positive pole, the output of described operational amplifier U1B connects the positive pole of described diode D2A and diode D2B, institute
State the second end of resistance R 12 and the second end of described resistance R 14 respectively with negative pole and described two utmost points of described diode D1A
The negative pole of pipe D2B connects, and the negative pole of described diode D2A is connected with the negative pole of diode D1B, described capacitor C 1
First end connect the positive pole of described operational amplifier U1A working power, the second end ground connection of described capacitor C 1.
7. interchange protection circuit against input over-voltage according to claim 6, is characterized in that, described crest voltage sampling unit by
Resistance R 15, capacitor C 3 and resistance R 16 form, and wherein, described resistance 15 first ends connect of described capacitor C 3
The first end of one end and described resistance R 16, the second end of described resistance 15 connects described diode D2A and diode D1B
Negative pole, the second end of described capacitor C 3 be connected with described resistance R 16 after and ground connection.
8. interchange protection circuit against input over-voltage according to claim 7, is characterized in that, described overvoltage return difference unit is by resistance
R3, resistance R 9, resistance R 17, resistance R 18, comparator U2, capacitor C 2 and voltage-stabiliser tube Z1 composition, wherein,
The first termination one predeterminated voltage of described resistance R 9, the first end of described resistance R 17 connects described crest voltage sampling unit
In the first end of described resistance R 15, the second end of described resistance R 9 and the second end of described resistance R 17 respectively with institute
The positive input terminal of stating comparator U2 is connected with negative input end, and described comparator U2 output connects of described resistance R 3
One end, the second end of described resistance R 3 connects the positive pole of described voltage-stabiliser tube Z1 and the first end of described resistance R 18, and the second end of described resistance R 18 connects the second end of described resistance R 9, the minus earth of described voltage-stabiliser tube Z1.
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| CN201410078392.3A CN103944140B (en) | 2014-03-05 | 2014-03-05 | Alternating-current input overvoltage protection circuit |
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| CN105790220A (en) * | 2014-12-17 | 2016-07-20 | 国家电网公司 | Short-circuit protection circuit and method for half-bridge topology converter |
| CN108429239A (en) * | 2018-04-24 | 2018-08-21 | 广州金升阳科技有限公司 | A kind of output overvoltage protection circuit and the power supply comprising the circuit |
| CN108627746A (en) * | 2018-07-20 | 2018-10-09 | 哈尔滨理工大学 | Bipolarity Weak absorption device for Insulation monitoring |
| CN114498551A (en) * | 2022-04-18 | 2022-05-13 | 青岛鼎信通讯股份有限公司 | Overvoltage protection method, device, equipment and medium for single-phase electric energy meter |
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| CN105790220A (en) * | 2014-12-17 | 2016-07-20 | 国家电网公司 | Short-circuit protection circuit and method for half-bridge topology converter |
| CN105790220B (en) * | 2014-12-17 | 2018-10-23 | 国家电网公司 | A kind of half-bridge topology converter short-circuit protection circuit and method |
| CN108429239A (en) * | 2018-04-24 | 2018-08-21 | 广州金升阳科技有限公司 | A kind of output overvoltage protection circuit and the power supply comprising the circuit |
| CN108627746A (en) * | 2018-07-20 | 2018-10-09 | 哈尔滨理工大学 | Bipolarity Weak absorption device for Insulation monitoring |
| CN114498551A (en) * | 2022-04-18 | 2022-05-13 | 青岛鼎信通讯股份有限公司 | Overvoltage protection method, device, equipment and medium for single-phase electric energy meter |
| CN114498551B (en) * | 2022-04-18 | 2022-07-01 | 青岛鼎信通讯股份有限公司 | Overvoltage protection method, device, equipment and medium for single-phase electric energy meter |
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| CN103944140B (en) | 2016-08-17 |
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