CN205210170U - Supply hourglass current detection circuit of ADC sampling - Google Patents
Supply hourglass current detection circuit of ADC sampling Download PDFInfo
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- CN205210170U CN205210170U CN201520815164.XU CN201520815164U CN205210170U CN 205210170 U CN205210170 U CN 205210170U CN 201520815164 U CN201520815164 U CN 201520815164U CN 205210170 U CN205210170 U CN 205210170U
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Abstract
The utility model discloses a supply hourglass current detection circuit of ADC sampling, its voltage signal that can obtain to be suitable for ADC to adopt. This supply hourglass current detection circuit of ADC sampling includes current transformer detection circuitry, and it is used for exporting differential voltage signal, with the difference filter circuit that the current transformer detection circuitry electricity is connected, it is arranged in filtering current transformer detection circuitry power supply to be coupled to the high frequency ripple in the leakage current signal, with the difference proportion amplifier circuit that current transformer detection circuitry electricity is connected, be used for with the differential voltage signal of current transformer detection circuitry output converts single ended signal into to the proportion of doing is enlargied, with the electric 4 rank butterworth filters of being connected of difference proportion amplifier circuit for filtering high frequency ripple carries out the proportion to the signal and enlargies, with the electric absolute value circuit of being connected of 4 rank butterworth filters for the industry frequency alternate current signal that to input this absolute value circuit changes the steamed bun ripples into, satisfies the voltage that the ADC sampling required with output.
Description
Technical field
The utility model belongs to the technical field of leakage current detection circuit, specifically relates to a kind of leakage current detection circuit for ADC sampling.
Background technology
The Chinese utility model patent that notification number is 203376382U, publication date is on 01 01st, 2014 discloses a kind of leak current detection device, comprise toroidal core, it is characterized in that, live wire and center line pass toroidal core as primary coil, toroidal core is also wound with secondary coil, secondary coil connection signal amplifying circuit, signal amplification circuit connection signal comparator circuit, signal comparator circuit connects leakage current signal designation pin, and described toroidal core is provided with radome.The signal exported through amplifying circuit in the leak current detection device of this structure is unsuitable for ADC sampling.
Utility model content
The purpose of this utility model is to provide a kind of leakage current detection circuit for ADC sampling, and it can obtain the voltage signal being suitable for ADC and adopting.
For solving the problems of the technologies described above, the purpose of this utility model is achieved in that a kind of leakage current detection circuit for ADC sampling, and it is characterized in that: comprise current transformer testing circuit, it is for output difference divided voltage signal; The differential filtering circuit be electrically connected with described current transformer testing circuit, it is coupled to the high frequency ripple in leakage current signal for power supply in filtering current transformer testing circuit; The difference scaling circuit be electrically connected with current transformer testing circuit, is converted to single-ended signal for the differential voltage signal exported by described current transformer testing circuit, and makes scale amplifying; The 4 rank Butterworth filters that are electrically connected with difference scaling circuit, carry out scale amplifying for filtering high frequency ripple to signal; The absolute value circuit be electrically connected with 4 rank Butterworth filters, for changing the industrial frequency AC signal of this absolute value circuit of input into steamed bun ripple, to export the voltage meeting ADC sampling request.
On the basis of such scheme and as the preferred version of such scheme: described current transformer testing circuit comprises current transformer, described current transformer comprises magnetic core, magnetic core is wound with former limit winding, the first vice-side winding and the second vice-side winding, first vice-side winding is electrically connected with the second vice-side winding through the first resistance, the second resistance, and the common port between the first resistance and the second resistance connects power supply.
On the basis of such scheme and as the preferred version of such scheme: described differential filtering circuit comprises the 3rd resistance and the 4th resistance, power supply is electrically connected with the in-phase input end of the first operational amplifier through described 3rd resistance and the 4th resistance, the inverting input of the first operational amplifier is electrically connected with one end of the 8th resistance, common port between the inverting input of the first operational amplifier and the 8th resistance is through the 9th resistance eutral grounding, the output terminal of the first operational amplifier is through the second capacity earth, the in-phase input end of the first operational amplifier is electrically connected through the output terminal of the first electric capacity with the first operational amplifier, the output terminal of the first operational amplifier is electrically connected with the inverting input of the second operational amplifier through the 6th resistance, common port between the inverting input of the second operational amplifier and the 6th resistance is through the 7th resistance eutral grounding, common port between 3rd resistance and the 4th resistance is electrically connected with the in-phase input end of the second operational amplifier through the 5th resistance, one end of 3rd electric capacity is electrically connected with the in-phase input end of the second operational amplifier, the other end of the 3rd electric capacity is electrically connected with the output terminal of the second operational amplifier, the output terminal of the second operational amplifier is through the 4th capacity earth, the output terminal of the second operational amplifier is electrically connected with the other end of the 8th resistance.
On the basis of such scheme and as the preferred version of such scheme: described difference scaling circuit comprises the 3rd operational amplifier, the in-phase input end of the 3rd operational amplifier is connected electrically on the common port between the first vice-side winding and the first resistance, the output terminal of the 3rd operational amplifier is electrically connected through the in-phase input end of the 11 resistance with the 5th operational amplifier, common port between the in-phase input end of the 5th operational amplifier and the 11 resistance is through the 16 resistance eutral grounding, the in-phase input end of four-operational amplifier is connected electrically on the common port between the second vice-side winding and the second resistance, the output terminal of four-operational amplifier is electrically connected through the inverting input of the 15 resistance with the 5th operational amplifier, the output terminal of the 3rd operational amplifier is successively through the 12 resistance, 13 resistance, 14 resistance is electrically connected with the output terminal of four-operational amplifier, the inverting input of the 3rd operational amplifier is connected electrically on the common port between the 12 resistance and the 13 resistance, the inverting input of four-operational amplifier is connected electrically on the common port between the 13 resistance and the 14 resistance, one end of 17 resistance is connected electrically on the common port between the inverting input of the 5th operational amplifier and the 15 resistance, the other end of the 17 resistance is connected electrically on the output terminal of the 5th operational amplifier.
On the basis of such scheme and as the preferred version of such scheme: described 4 rank Butterworth filters comprise the 18 resistance, 18 resistance is connected electrically in through the 19 resistance on the in-phase input end of the 6th operational amplifier, the in-phase input end of the 6th operational amplifier is through the 6th capacity earth, the inverting input of the 6th operational amplifier is through the 20 resistance eutral grounding, one end of 21 resistance is connected electrically on the common port between the inverting input of the 6th operational amplifier and the 20 resistance, the other end of the 21 resistance is connected electrically on the output terminal of the 6th operational amplifier, one end of 5th electric capacity is connected electrically on the common port between the 18 resistance and the 19 resistance, the other end of the 5th electric capacity is connected electrically on the output terminal of the 6th operational amplifier, the output terminal of the 6th operational amplifier is through the 22 resistance, 23 resistance is connected electrically on the in-phase input end of the 7th operational amplifier, the in-phase input end of the 7th operational amplifier is through the 7th capacity earth, the inverting input of the 7th operational amplifier is electrically connected with the output terminal of the 7th operational amplifier, one end of 8th electric capacity is connected electrically on the common port between the 22 resistance and the 23 resistance, the other end of the 8th electric capacity is connected electrically on the output terminal of the 7th operational amplifier.
On the basis of such scheme and as the preferred version of such scheme: described absolute value circuit comprises the 24 resistance, one end of 24 resistance is electrically connected with the inverting input of the 8th operational amplifier, the in-phase input end of the 8th operational amplifier is through the 27 resistance eutral grounding, the output terminal of the 8th operational amplifier is electrically connected with the positive pole of the first diode, the negative pole of the first diode is electrically connected with one end of the 25 resistance, the other end of the 25 resistance is electrically connected with the other end of the 24 resistance, the positive pole of the second diode is connected electrically on the common port between the inverting input of the 8th operational amplifier and the 24 resistance, the negative electricity of the second diode is connected on the output terminal of the 8th operational amplifier, 9th electric capacity and the second diodes in parallel, one end of 26 resistance is connected electrically on the common port between the inverting input of the 8th operational amplifier and the 24 resistance, the other end of the 26 resistance is connected electrically on the common port between the negative pole of the first diode and the 25 resistance, first diode, common port between 25 resistance and the 26 resistance is output voltage terminal.
On the basis of such scheme and as the preferred version of such scheme: described first operational amplifier, the second operational amplifier all adopt single power supply mode.
On the basis of such scheme and as the preferred version of such scheme: described 3rd operational amplifier, four-operational amplifier, the 5th operational amplifier all adopt dual power supply mode.
On the basis of such scheme and as the preferred version of such scheme: described 6th operational amplifier, the 7th operational amplifier all adopt dual power supply mode.
On the basis of such scheme and as the preferred version of such scheme: described 8th operational amplifier adopts dual power supply mode.
The utility model gives prominence to compared to existing technology and useful technique effect is:
Leakage current detection circuit of the present utility model, have employed current transformer testing circuit, differential filtering circuit, difference scaling circuit, 4 rank Butterworth filters and absolute value circuit structure, original leakage current is converted to the voltage signal of equal proportion, by amplifying voltage signal, filtering and taking absolute value, make it become to be suitable for the voltage signal of ADC sampling.
Accompanying drawing explanation
Fig. 1 is circuit theory schematic diagram of the present utility model.
Fig. 2 is the bode figure using MATLAB to draw quadravalence Butterworth filter transport function.
Embodiment
The utility model is further described with specific embodiment below in conjunction with accompanying drawing, see Fig. 1 mono-Fig. 2;
It should be noted that, " first " alleged in the present embodiment, " second ", " the 3rd ", " the 4th ", " the 5th ", " the 6th ", " the 7th ", " the 8th ", " the 9th ", " the tenth ", " the 11 ", " the 12 ", " the 13 ", " the 14 ", " the 15 ", " the 16 ", " the 17 ", " the 18 ", " the 19 ", " the 20 ", " the 21 ", " the 22 ", " the 23 ", " the 24 ", " the 25 ", " the 26 ", " the 27 " is not to the restriction quantitatively of correlation technique feature, but in order to distinguish the name that generic technical characteristic is made.
This gives a kind of leakage current detection circuit for ADC sampling, comprise current transformer testing circuit, differential filtering circuit, difference scaling circuit, 4 rank Butterworth filter and absolute value circuits.Wherein, current transformer testing circuit is used for output difference divided voltage signal; The differential filtering circuit be electrically connected with described current transformer, it is coupled to the high frequency ripple in leakage current signal for power supply in filtering current transformer testing circuit; The difference scaling circuit be electrically connected with current transformer testing circuit, is converted to single-ended signal for the differential voltage signal exported by described current transformer testing circuit, and makes scale amplifying; The 4 rank Butterworth filters that are electrically connected with difference scaling circuit, carry out scale amplifying for filtering high frequency ripple to signal; The absolute value circuit be electrically connected with 4 rank Butterworth filters, for changing the industrial frequency AC signal of this absolute value circuit of input into steamed bun ripple, to export the voltage meeting ADC sampling request.
Leakage current detection circuit of the present utility model, have employed current transformer testing circuit, differential filtering circuit, difference scaling circuit, 4 rank Butterworth filters and absolute value circuit structure, original leakage current is converted to the voltage signal of equal proportion, by amplifying voltage signal, filtering and taking absolute value, make it become to be suitable for the voltage signal of ADC sampling.
In the present embodiment, as shown in fig. 1, described current transformer testing circuit comprises current transformer, and described current transformer comprises magnetic core, and magnetic core is wound with former limit winding, the first vice-side winding and the second vice-side winding.Usually, former limit winding is 1 circle, and it is formed by the magnetic core of former limit winding through current transformer, and the first vice-side winding and the second vice-side winding adopt 100 circle enameled wire coilings to form respectively.First vice-side winding is electrically connected with the second vice-side winding through the first resistance R1, the second resistance R2, and the common port between the first resistance and the second resistance connects power supply.In the present embodiment, power supply is+5V.In this current transformer testing circuit, the common port between the first vice-side winding and the first resistance and the common port between the second vice-side winding and the second resistance as output terminal, with output difference divided voltage signal.During work, secondary current is former limit 1/100, and the 200 Ω resistance that this electric current flows through vice-side winding series connection produce pressure drop, and current signal is converted to voltage signal.
In the present embodiment, described differential filtering circuit comprises the 3rd resistance R3 and the 4th resistance R4, power supply is electrically connected with the in-phase input end of the first operational amplifier through described 3rd resistance R3 and the 4th resistance R4, the inverting input of the first operational amplifier is electrically connected with one end of the 8th resistance R8, common port between the inverting input of the first operational amplifier and the 8th resistance R8 is through the 9th resistance R9 ground connection, the output terminal of the first operational amplifier is through the second electric capacity C2 ground connection, the in-phase input end of the first operational amplifier is electrically connected with the output terminal of the first operational amplifier through the first electric capacity C1, the output terminal of the first operational amplifier is electrically connected with the inverting input of the second operational amplifier through the 6th resistance R6, common port between the inverting input of the second operational amplifier and the 6th resistance R6 is through the 7th resistance R7 ground connection, common port between 3rd resistance R3 and the 4th resistance R4 is electrically connected with the in-phase input end of the second operational amplifier through the 5th resistance R5, one end of 3rd electric capacity C3 is electrically connected with the in-phase input end of the second operational amplifier, the other end of the 3rd electric capacity C3 is electrically connected with the output terminal of the second operational amplifier, the output terminal of the second operational amplifier is through the 4th electric capacity C4 ground connection.The output terminal of the second operational amplifier is electrically connected with the other end of the 8th resistance R8.In the present embodiment, described first operational amplifier, the second operational amplifier all adopt single power supply mode.In this differential filtering circuit, common port between the output terminal of the second operational amplifier and the 8th resistance and the common port between the output terminal of the first operational amplifier and the 6th resistance, as output terminal, are respectively used to the different name end electrical connection with the first vice-side winding and the second vice-side winding.In high-power system application, power supply+5V can be disturbed by power circuit, comprises high frequency ripple, because+5V power supply powers to current transformer secondary, this undesired signal can be coupled in leakage current test signal, if do not carry out effective filtering, can reduce the accuracy of detection of whole system.Two terminals of differential filtering circuit connect the different name end of current transformer two windings respectively, can carry out effective filtering to the high frequency ripple that power supply is coupled in leakage current signal.
In the present embodiment, described difference scaling circuit comprises the 3rd operational amplifier, the in-phase input end of the 3rd operational amplifier is connected electrically on the common port between the first vice-side winding and the first resistance R1, the output terminal of the 3rd operational amplifier is electrically connected with the in-phase input end of the 5th operational amplifier through the 11 resistance R11, common port between the in-phase input end of the 5th operational amplifier and the 11 resistance R11 is through the 16 resistance R16 ground connection, the in-phase input end of four-operational amplifier is connected electrically on the common port between the second vice-side winding and the second resistance R2, the output terminal of four-operational amplifier is electrically connected with the inverting input of the 5th operational amplifier through the 15 resistance R15, the output terminal of the 3rd operational amplifier is successively through the 12 resistance R12,13 resistance R13,14 resistance R14 is electrically connected with the output terminal of four-operational amplifier, the inverting input of the 3rd operational amplifier is connected electrically on the common port between the 12 resistance R12 and the 13 resistance R13, the inverting input of four-operational amplifier is connected electrically on the common port between the 13 resistance R13 and the 14 resistance R14, one end of 17 resistance R17 is connected electrically on the common port between the inverting input of the 5th operational amplifier and the 15 resistance R15, the other end of the 17 resistance R17 is connected electrically on the output terminal of the 5th operational amplifier.In this difference scaling circuit, the common port between the output terminal of the 5th operational amplifier and the 17 resistance R17 is as output terminal.In the present embodiment, described 3rd operational amplifier, four-operational amplifier, the 5th operational amplifier all adopt dual power supply mode.Difference scaling circuit effectively can suppress common mode interference, differential signal is converted to single-ended signal simultaneously, is beneficial to follow-up signal condition, and carries out Linear Amplifer to differential signal.Because leakage current signal includes high frequency ripple, high-frequency interferencing signal, while being carried out amplifying by effective leakage current signal, also amplifies by difference scaling circuit.When leakage current detection circuit is applied in high-power circuit, high frequency interference spike is larger, if the ratio of gains of difference scaling circuit is larger, then output signal medium-high frequency spike can be made to exceed the output upper voltage limit of operational amplifier, cause distorted signals.Therefore, getting gain in the design is 2.5.
In the present embodiment, described 4 rank Butterworth filters comprise the 18 resistance R18, 18 resistance R18 is connected electrically in through the 19 resistance R19 on the in-phase input end of the 6th operational amplifier, the in-phase input end of the 6th operational amplifier is through the 6th electric capacity C6 ground connection, the inverting input of the 6th operational amplifier is through the 20 resistance R20 ground connection, one end of 21 resistance R21 is connected electrically on the common port between the inverting input of the 6th operational amplifier and the 20 resistance R20, the other end of the 21 resistance R21 is connected electrically on the output terminal of the 6th operational amplifier, one end of 5th electric capacity C5 is connected electrically on the common port between the 18 resistance R18 and the 19 resistance R19, the other end of the 5th electric capacity C5 is connected electrically on the output terminal of the 6th operational amplifier, the output terminal of the 6th operational amplifier is through the 22 resistance R22, 23 resistance R23 is connected electrically on the in-phase input end of the 7th operational amplifier, the in-phase input end of the 7th operational amplifier is through the 7th electric capacity C7 ground connection, the inverting input of the 7th operational amplifier is electrically connected with the output terminal of the 7th operational amplifier, one end of 8th electric capacity C8 is connected electrically on the common port between the 22 resistance R22 and the 23 resistance R23, the other end of the 8th electric capacity C8 is connected electrically on the output terminal of the 7th operational amplifier.In the present embodiment, described 6th operational amplifier, the 7th operational amplifier all adopt dual power supply mode.
Butterworth filter input signal is the superposition of fundamental frequency and high frequency ripple, and high frequency ripple is inverter switching frequency time ripple mainly, and high frequency ripple needs by filtering.The switching frequency of inverter is generally 10kHz or higher, therefore the corner frequency of Butterworth filter is set to 500Hz.
Select quadravalence Butterworth filter, its coefficient is a1=1.8478, b1=1; A2=0.7654, b2=1.
MATLAB is used to draw the bode figure of quadravalence Butterworth filter transport function
MATLAB program is:
R1＝15.8*10^3；
R2＝43.2*10^3；
c3＝4.7*10^(-9)；
c4＝33*10^(-9)；
R3＝21.5*10^3；
R4＝30.1*10^3；
A0＝1+10^3/10^3；
a1＝R1*R2*c1*c2
a2＝(c1*(R1+R2)+(1-A0)*R1*c2)
A1＝tf([A0]，[a1a21])
a3＝R3*R4*c3*c4
a4＝c3*(R3+R4)
A2＝tf([1]，[a3a41])
A＝A1*A2
bode(A)
margin(A)
Bode schemes, and as shown in Figure 2, as can be seen from the figure, the cross-over frequency of wave filter is 656Hz, decays during high frequency with-80db/dec, can effectively filtering high frequency ripple.At power frequency 50Hz place, the gain of wave filter is 6.12db, and near it, change in gain of frequency is very little, and therefore wave filter can carry out undistorted amplification to power frequency leakage current signal.
In the present embodiment, described absolute value circuit comprises the 24 resistance R24, one end of 24 resistance R24 is electrically connected with the inverting input of the 8th operational amplifier, the in-phase input end of the 8th operational amplifier is through the 27 resistance R27 ground connection, the output terminal of the 8th operational amplifier is electrically connected with the positive pole of the first diode D1, the negative pole of the first diode D1 is electrically connected with one end of the 25 resistance R25, the other end of the 25 resistance R25 is electrically connected with the other end of the 24 resistance R24, the positive pole of the second diode D2 is connected electrically on the common port between the inverting input of the 8th operational amplifier and the 24 resistance R24, the negative electricity of the second diode D2 is connected on the output terminal of the 8th operational amplifier, 9th electric capacity C9 is in parallel with the second diode D2, one end of 26 resistance R26 is connected electrically on the common port between the inverting input of the 8th operational amplifier and the 24 resistance R24, the other end of the 26 resistance R26 is connected electrically on the common port between the negative pole of the first diode D1 and the 25 resistance R25, first diode D1, common port between 25 resistance R25 and the 26 resistance R26 is output voltage terminal.In the present embodiment, described 8th operational amplifier adopts dual power supply mode.The absolute value circuit structure of this structure is simple.
Above-described embodiment is only preferred embodiment of the present utility model, not limits protection domain of the present utility model according to this, therefore: all equivalence changes done according to structure of the present utility model, shape, principle, all should be covered by within protection domain of the present utility model.
Claims (10)
1., for a leakage current detection circuit for ADC sampling, it is characterized in that: comprise current transformer testing circuit, it is for output difference divided voltage signal;
The differential filtering circuit be electrically connected with described current transformer testing circuit, it is coupled to the high frequency ripple in leakage current signal for power supply in filtering current transformer testing circuit;
The difference scaling circuit be electrically connected with current transformer testing circuit, is converted to single-ended signal for the differential voltage signal exported by described current transformer testing circuit, and makes scale amplifying;
The 4 rank Butterworth filters that are electrically connected with difference scaling circuit, carry out scale amplifying for filtering high frequency ripple to signal;
The absolute value circuit be electrically connected with 4 rank Butterworth filters, for changing the industrial frequency AC signal of this absolute value circuit of input into steamed bun ripple, to export the voltage meeting ADC sampling request.
2. the leakage current detection circuit for ADC sampling according to claim 1, it is characterized in that: described current transformer testing circuit comprises current transformer, described current transformer comprises magnetic core, magnetic core is wound with former limit winding, the first vice-side winding and the second vice-side winding, first vice-side winding is electrically connected with the second vice-side winding through the first resistance, the second resistance, and the common port between the first resistance and the second resistance connects power supply.
3. the leakage current detection circuit for ADC sampling according to claim 2, it is characterized in that: described differential filtering circuit comprises the 3rd resistance and the 4th resistance, power supply is electrically connected with the in-phase input end of the first operational amplifier through described 3rd resistance and the 4th resistance, the inverting input of the first operational amplifier is electrically connected with one end of the 8th resistance, common port between the inverting input of the first operational amplifier and the 8th resistance is through the 9th resistance eutral grounding, the output terminal of the first operational amplifier is through the second capacity earth, the in-phase input end of the first operational amplifier is electrically connected through the output terminal of the first electric capacity with the first operational amplifier, the output terminal of the first operational amplifier is electrically connected with the inverting input of the second operational amplifier through the 6th resistance, common port between the inverting input of the second operational amplifier and the 6th resistance is through the 7th resistance eutral grounding, common port between 3rd resistance and the 4th resistance is electrically connected with the in-phase input end of the second operational amplifier through the 5th resistance, one end of 3rd electric capacity is electrically connected with the in-phase input end of the second operational amplifier, the other end of the 3rd electric capacity is electrically connected with the output terminal of the second operational amplifier, the output terminal of the second operational amplifier is through the 4th capacity earth, the output terminal of the second operational amplifier is electrically connected with the other end of the 8th resistance.
4. the leakage current detection circuit for ADC sampling according to claim 2, it is characterized in that: described difference scaling circuit comprises the 3rd operational amplifier, the in-phase input end of the 3rd operational amplifier is connected electrically on the common port between the first vice-side winding and the first resistance, the output terminal of the 3rd operational amplifier is electrically connected through the in-phase input end of the 11 resistance with the 5th operational amplifier, common port between the in-phase input end of the 5th operational amplifier and the 11 resistance is through the 16 resistance eutral grounding, the in-phase input end of four-operational amplifier is connected electrically on the common port between the second vice-side winding and the second resistance, the output terminal of four-operational amplifier is electrically connected through the inverting input of the 15 resistance with the 5th operational amplifier, the output terminal of the 3rd operational amplifier is successively through the 12 resistance, 13 resistance, 14 resistance is electrically connected with the output terminal of four-operational amplifier, the inverting input of the 3rd operational amplifier is connected electrically on the common port between the 12 resistance and the 13 resistance, the inverting input of four-operational amplifier is connected electrically on the common port between the 13 resistance and the 14 resistance, one end of 17 resistance is connected electrically on the common port between the inverting input of the 5th operational amplifier and the 15 resistance, the other end of the 17 resistance is connected electrically on the output terminal of the 5th operational amplifier.
5. the leakage current detection circuit for ADC sampling according to claim 1, it is characterized in that: described 4 rank Butterworth filters comprise the 18 resistance, 18 resistance is connected electrically in through the 19 resistance on the in-phase input end of the 6th operational amplifier, the in-phase input end of the 6th operational amplifier is through the 6th capacity earth, the inverting input of the 6th operational amplifier is through the 20 resistance eutral grounding, one end of 21 resistance is connected electrically on the common port between the inverting input of the 6th operational amplifier and the 20 resistance, the other end of the 21 resistance is connected electrically on the output terminal of the 6th operational amplifier, one end of 5th electric capacity is connected electrically on the common port between the 18 resistance and the 19 resistance, the other end of the 5th electric capacity is connected electrically on the output terminal of the 6th operational amplifier, the output terminal of the 6th operational amplifier is through the 22 resistance, 23 resistance is connected electrically on the in-phase input end of the 7th operational amplifier, the in-phase input end of the 7th operational amplifier is through the 7th capacity earth, the inverting input of the 7th operational amplifier is electrically connected with the output terminal of the 7th operational amplifier, one end of 8th electric capacity is connected electrically on the common port between the 22 resistance and the 23 resistance, the other end of the 8th electric capacity is connected electrically on the output terminal of the 7th operational amplifier.
6. the leakage current detection circuit for ADC sampling according to claim 1, it is characterized in that: described absolute value circuit comprises the 24 resistance, one end of 24 resistance is electrically connected with the inverting input of the 8th operational amplifier, the in-phase input end of the 8th operational amplifier is through the 27 resistance eutral grounding, the output terminal of the 8th operational amplifier is electrically connected with the positive pole of the first diode, the negative pole of the first diode is electrically connected with one end of the 25 resistance, the other end of the 25 resistance is electrically connected with the other end of the 24 resistance, the positive pole of the second diode is connected electrically on the common port between the inverting input of the 8th operational amplifier and the 24 resistance, the negative electricity of the second diode is connected on the output terminal of the 8th operational amplifier, 9th electric capacity and the second diodes in parallel, one end of 26 resistance is connected electrically on the common port between the inverting input of the 8th operational amplifier and the 24 resistance, the other end of the 26 resistance is connected electrically on the common port between the negative pole of the first diode and the 25 resistance, first diode, common port between 25 resistance and the 26 resistance is output voltage terminal.
7. the leakage current detection circuit for ADC sampling according to claim 3, is characterized in that: described first operational amplifier, the second operational amplifier all adopt single power supply mode.
8. the leakage current detection circuit for ADC sampling according to claim 4, is characterized in that: described 3rd operational amplifier, four-operational amplifier, the 5th operational amplifier all adopt dual power supply mode.
9. the leakage current detection circuit for ADC sampling according to claim 5, is characterized in that: described 6th operational amplifier, the 7th operational amplifier all adopt dual power supply mode.
10. the leakage current detection circuit for ADC sampling according to claim 6, is characterized in that: described 8th operational amplifier adopts dual power supply mode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520815164.XU CN205210170U (en) | 2015-10-14 | 2015-10-14 | Supply hourglass current detection circuit of ADC sampling |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520815164.XU CN205210170U (en) | 2015-10-14 | 2015-10-14 | Supply hourglass current detection circuit of ADC sampling |
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| CN205210170U true CN205210170U (en) | 2016-05-04 |
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| CN201520815164.XU Withdrawn - After Issue CN205210170U (en) | 2015-10-14 | 2015-10-14 | Supply hourglass current detection circuit of ADC sampling |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105403759A (en) * | 2015-10-14 | 2016-03-16 | 嘉兴金尚节能科技有限公司 | Leakage current detection circuit for ADC sampling |
| CN106685029A (en) * | 2017-01-11 | 2017-05-17 | 天地（常州）自动化股份有限公司 | Wireless charging device and metal foreign substance detection method thereof |
| CN108761284A (en) * | 2018-05-18 | 2018-11-06 | 北京华峰测控技术股份有限公司 | Drain leakage test circuit in field-effect tube breakdown voltage characteristics and method |
| CN113552406A (en) * | 2021-07-27 | 2021-10-26 | 上海电机学院 | High-precision residual current detection device powered by single power supply |
-
2015
- 2015-10-14 CN CN201520815164.XU patent/CN205210170U/en not_active Withdrawn - After Issue
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105403759A (en) * | 2015-10-14 | 2016-03-16 | 嘉兴金尚节能科技有限公司 | Leakage current detection circuit for ADC sampling |
| CN105403759B (en) * | 2015-10-14 | 2018-03-27 | 嘉兴金尚节能科技有限公司 | For the leakage current detection circuit of ADC samplings |
| CN106685029A (en) * | 2017-01-11 | 2017-05-17 | 天地（常州）自动化股份有限公司 | Wireless charging device and metal foreign substance detection method thereof |
| CN108761284A (en) * | 2018-05-18 | 2018-11-06 | 北京华峰测控技术股份有限公司 | Drain leakage test circuit in field-effect tube breakdown voltage characteristics and method |
| CN113552406A (en) * | 2021-07-27 | 2021-10-26 | 上海电机学院 | High-precision residual current detection device powered by single power supply |
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