CN203798845U - Current sampling circuit with temperature drift compensation - Google Patents
Current sampling circuit with temperature drift compensation Download PDFInfo
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- CN203798845U CN203798845U CN201420202182.6U CN201420202182U CN203798845U CN 203798845 U CN203798845 U CN 203798845U CN 201420202182 U CN201420202182 U CN 201420202182U CN 203798845 U CN203798845 U CN 203798845U
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- 238000005070 sampling Methods 0.000 title claims abstract description 61
- 238000001914 filtration Methods 0.000 claims abstract description 34
- 239000003990 capacitor Substances 0.000 claims description 33
- 230000003321 amplification Effects 0.000 claims description 15
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 15
- 230000001105 regulatory effect Effects 0.000 claims description 13
- 238000005516 engineering process Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 230000002277 temperature effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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Abstract
The utility model discloses a current sampling circuit with temperature drift compensation, which comprises a current acquisition circuit, a two-stage current filtering circuit, a current amplifying circuit, an NTC proportion adjusting circuit, a signal following circuit and a signal filtering circuit. The current sampling circuit with temperature drift compensation adopts a negative-temperature-coefficient thermistor as a device for temperature drift compensation of a sampling resistor, and combines an integral type proportional feedback circuit integrating operational amplifying and RC filtering, finally realizes the purpose that the current sampling value does not change with the variation of the temperature of the sampling resistor, and realizes accurate power control in occasions where the motor driver needs to carry out power control.
Description
Technical field
The utility model relates to a kind of current sampling circuit, relates in particular to a kind of current sampling circuit with temperature drift compensation.
Background technology
The at present measuring and calculating of power is using the product of electric current and voltage as account form substantially, voltage generally adopts resistance sampling or isolation line sampling, because there is large filter capacitor, so the sampling of general voltage is more accurate, and what use because of voltage sample is all the resistance of larger impedance, so power consumption is generally very little, substantially do not produce power consumption, in the time of variation of ambient temperature, do not have very large variation yet.But, the sampling of electric current is all the sampling resistor that adopts little impedance substantially, because the electric current of motor need to pass through sampling resistor, so the power consumption of sampling resistor can change according to actual requirement, and sampling resistor is all relatively near power model, thereby than being easier to by ambient temperature effect, cause sampling resistor resistance value in the time of temperature rise to become large, even if electric current does not change, it is large that sampled value also can become thereupon, need to carry out the occasion of operate power control at motor driver, finally cause power control inaccurate.The method that existing solution current sample temperature is floated problem is the testing circuit by environment temperature, utilizes software to compensate sampled value, but the method can take too much Single Chip Microcomputer (SCM) program space and data space conventionally.
Utility model content
The purpose of this utility model is, by a kind of current sampling circuit with temperature drift compensation, to solve the problem that above background technology part is mentioned.
For reaching this object, the utility model by the following technical solutions:
With a current sampling circuit for temperature drift compensation, it comprises current collection circuit, two-stage current filtering circuit, current amplification circuit, NTC ratio regulating circuit, signal follow circuit and signal filter circuit;
The input end of the output terminal of described current collection circuit and two-stage current filtering circuit is electrically connected, and for gather required voltage signal by sampling resistor, exports to two-stage current filtering circuit;
The output terminal of described two-stage current filtering circuit and the input end of current amplification circuit are electrically connected, for described voltage signal is carried out to filtering processing, and filtering high frequency interference;
The input end of the output terminal of described current amplification circuit and NTC ratio regulating circuit is electrically connected, for filtering signal after treatment is amplified to processing;
The output terminal of described NTC ratio regulating circuit and the input end of signal follow circuit are electrically connected, for basis, the temperature of sampling resistor described in the different temperatures stage is floated, test out several temperature corresponding point, again according to the parameter of negative tempperature coefficient thermistor (NTC) the corresponding temperature point adopting, select corresponding dividing potential drop mode, determine the ratio of feedback, obtain the sample voltage value of floating without temperature;
The output terminal of described signal follow circuit and the input end of signal filter circuit are electrically connected, for described sample voltage value of floating without temperature is carried out to impedance matching processing;
Described signal filter circuit is for carrying out the disposal of gentle filter to follow circuit output signal.
Especially, described current collection circuit is made up of the sampling resistor R1 being connected in parallel and sampling resistor R2, after sampling resistor R1 and sampling resistor R2 are connected in parallel, connects power model and public terminal GND.
Especially, described two-stage current filtering circuit is two-stage RC filtering circuit, comprises resistance R 3, capacitor C 1, resistance R 4, capacitor C 2; Node after one end of described resistance R 3 is connected with one end of resistance R 4 connects one end of capacitor C 1, the other end ground connection of capacitor C 1, and the other end of resistance R 4 is connected with one end of capacitor C 2, the other end ground connection of capacitor C 2.
Especially, described current amplification circuit comprises resistance R 5, resistance R 6, capacitor C 3 and amplifier U1, wherein, one end ground connection of described resistance R 5, the other end is connected with one end of resistance R 6, the reverse input end of amplifier U1, the other end of resistance R 6 is connected with the output terminal of amplifier U1, one end ground connection of capacitor C 3, and the other end connects the power end of amplifier U1.
Especially, described NTC ratio regulating circuit comprises resistance R 7 and negative tempperature coefficient thermistor R8, one end ground connection of resistance R 8, other end contact resistance R7.
Especially, described signal follow circuit comprises amplifier U2, and the reverse input end of described amplifier U2 connects its output terminal.
Especially, described signal filter circuit comprises resistance R 9 and capacitor C 4, one end ground connection of capacitor C 4, other end contact resistance R9.
The current sampling circuit with temperature drift compensation that the utility model provides adopts negative tempperature coefficient thermistor (Negative Temperature Coefficient, NTC) as the device of sampling resistor temperature drift compensation, and in conjunction with the monoblock type proportional feedback type circuit of amplifier and RC filtering one, finally realizing current sampling data does not change with the temperature variation of sampling resistor, the occasion that need to carry out operate power control at motor driver, realizes power control accurately.
Brief description of the drawings
The current sampling circuit structured flowchart with temperature drift compensation that Fig. 1 provides for the utility model embodiment;
The circuit diagram of the current sampling circuit with temperature drift compensation that Fig. 2 provides for the utility model embodiment.
Embodiment
Below in conjunction with drawings and Examples, the utility model is described in further detail.Be understandable that, specific embodiment described herein is only for explaining the utility model, but not to restriction of the present utility model.It also should be noted that, for convenience of description, in accompanying drawing, only show the part relevant to the utility model but not full content.
Please refer to shown in Fig. 1 the current sampling circuit structured flowchart with temperature drift compensation that Fig. 1 provides for the utility model embodiment.
Current sampling circuit with temperature drift compensation in the present embodiment specifically comprises: current collection circuit 101, two-stage current filtering circuit 102, current amplification circuit 103, NTC ratio regulating circuit 104, signal follow circuit 105 and signal filter circuit 106.
The input end of the output terminal of described current collection circuit 101 and two-stage current filtering circuit 102 is electrically connected, and for gather required voltage signal by sampling resistor, exports to two-stage current filtering circuit 102.
According to the cooperation of the size of power and rear class current amplification circuit 103, configure suitable accurate sampling resistor, make sampling electric current can be compared with the whole programme area of the reflection power of motor of system.
The output terminal of described two-stage current filtering circuit 102 and the input end of current amplification circuit 103 are electrically connected, for described voltage signal is carried out to filtering processing, and filtering high frequency interference.
According to the needs of different capacity system, by the circuit of configuration two-stage RC filtering, make to mate with the power samples of software, filtering high frequency interference, the autotelic integration of sampled point that real power is needed, makes speed and accuracy that power refreshes meet customer requirement.
The input end of the output terminal of described current amplification circuit 103 and NTC ratio regulating circuit 104 is electrically connected, for filtering signal after treatment is amplified to processing.
According to the requirement of chip AD (modulus) sample range and the consideration to amplifier linear zone, current amplification circuit 103 will be accomplished the magnitude of voltage that distortionless amplification two stage filter provides as far as possible.
The output terminal of described NTC ratio regulating circuit 104 and the input end of signal follow circuit 105 are electrically connected, for basis, the temperature of sampling resistor described in the different temperatures stage is floated, test out several temperature corresponding point, again according to the parameter of the negative tempperature coefficient thermistor corresponding temperature point adopting, select corresponding dividing potential drop mode, determine the ratio of feedback, obtain without the temperature sample voltage value of floating, make the performance number that calculates relatively accurate.
The input end of the output terminal of described signal follow circuit 105 and signal filter circuit 106 is electrically connected, for described sample voltage value of floating without temperature is carried out to impedance matching processing.
Adopt signal follow circuit 105, input impedance is increased, output impedance is little, so, concerning the Acquisition Circuit of small-signal, just little to the annoyance level of signal, and the little collection signal to single-chip microcomputer of output impedance provides good circuit to ensure.
Described signal filter circuit 106 is for carrying out the disposal of gentle filter to follow circuit output signal.
Signal after following is carried out smoothly, being conducive to the stability Calculation of power, make power seamlessly transitting within a certain period of time.
The utility model has successfully been used on water pump, and in the present embodiment, its physical circuit figure as shown in Figure 2.
Described current collection circuit 101 is made up of the sampling resistor R1 being connected in parallel and sampling resistor R2, after sampling resistor R1 and sampling resistor R2 are connected in parallel, connects power model and public terminal GND.
According to the demand of side circuit, current collection circuit 101 can adopt other the electric circuit constitutes, uses two resistance parallel connections here, and object is to expand powerful demand, improves the precision of sampling resistor simultaneously; Sampling resistor must be close to power model and public terminal GND, and the error of sampling can reduce much like this.
Described two-stage current filtering circuit 102 is two-stage RC filtering circuit, comprises resistance R 3, capacitor C 1, resistance R 4, capacitor C 2; Node after one end of described resistance R 3 is connected with one end of resistance R 4 connects one end of capacitor C 1, the other end ground connection of capacitor C 1, and the other end of resistance R 4 is connected with one end of capacitor C 2, the other end ground connection of capacitor C 2.
The cooperation of different resistances and electric capacity can be more level and smooth to sampled signal filtering, make to become with electric current more linear relation, the sample mode to software simultaneously, can do a synchronous finishing.Regulating resistance R3, resistance R 4, capacitor C 1, capacitor C 2 all can be adjusted the filtering time.
Described current amplification circuit 103 comprises resistance R 5, resistance R 6, capacitor C 3 and amplifier U1, wherein, one end ground connection of described resistance R 5, the other end is connected with one end of resistance R 6, the reverse input end of amplifier U1, the other end of resistance R 6 is connected with the output terminal of amplifier U1, one end ground connection of capacitor C 3, the other end connects the power end of amplifier U1.Magnification ratio can regulate by adjusting resistance R5, resistance R 6 sizes.
Described NTC ratio regulating circuit 104 comprises resistance R 7 and negative tempperature coefficient thermistor R8, one end ground connection of resistance R 8, other end contact resistance R7.
To do the feedback compensation of a negative ratio with the rising of temperature due to sampling resistor R1, sampling resistor R2 collection signal, the resistance of adjusting resistance R7 can regulate the ratio of feedback.
Described signal follow circuit 105 comprises amplifier U2, and the reverse input end of amplifier U2 connects its output terminal.
Described sample voltage value of floating without temperature is carried out impedance matching processing, not only reduces the impact on signal source, and improves the ability to single-chip microcomputer signals collecting.
Described signal filter circuit 106 comprises resistance R 9 and capacitor C 4, one end ground connection of capacitor C 4, other end contact resistance R9.Different filtering modes has a certain impact to the collection of power, and the present embodiment adopts the smothing filtering mode of the large electric capacity of large resistance.
The technical solution of the utility model adopts the device of negative tempperature coefficient thermistor as sampling resistor temperature drift compensation, and in conjunction with the monoblock type proportional feedback type circuit of amplifier and RC filtering one, finally realizing current sampling data does not change with the temperature variation of sampling resistor, the occasion that need to carry out operate power control at motor driver, realizes power control accurately.
Note; above are only preferred embodiment of the present utility model and institute's application technology principle; what the utility model was involved is not a single circuit; but the allomeric function cooperatively interacting of whole circuit; no matter negative tempperature coefficient thermistor is placed on which position of circuit in circuit structure; as long as having directly with the signal of electric current or proportionate relationship indirectly, the use of this circuit is just included among protection domain of the present utility model so.Skilled person in the art will appreciate that the utility model is not limited to specific embodiment described here, can carry out for a person skilled in the art various obvious variations, readjust and substitute and can not depart from protection domain of the present utility model.Therefore, although the utility model is described in further detail by above embodiment, but the utility model is not limited only to above embodiment, in the situation that not departing from the utility model design, can also comprise more other equivalent embodiment, and scope of the present utility model is determined by appended claim scope.
Claims (7)
1. the current sampling circuit with temperature drift compensation, is characterized in that, comprises current collection circuit, two-stage current filtering circuit, current amplification circuit, NTC ratio regulating circuit, signal follow circuit and signal filter circuit; Wherein, the input end of the output terminal of described current collection circuit and two-stage current filtering circuit is electrically connected; The output terminal of described two-stage current filtering circuit and the input end of current amplification circuit are electrically connected; The input end of the output terminal of described current amplification circuit and NTC ratio regulating circuit is electrically connected; The output terminal of described NTC ratio regulating circuit and the input end of signal follow circuit are electrically connected; The output terminal of described signal follow circuit and the input end of signal filter circuit are electrically connected.
2. the current sampling circuit with temperature drift compensation according to claim 1, it is characterized in that, described current collection circuit is made up of the sampling resistor R1 being connected in parallel and sampling resistor R2, after sampling resistor R1 and sampling resistor R2 are connected in parallel, connects power model and public terminal GND.
3. the current sampling circuit with temperature drift compensation according to claim 2, is characterized in that, described two-stage current filtering circuit is two-stage RC filtering circuit, comprises resistance R 3, capacitor C 1, resistance R 4, capacitor C 2; Node after one end of described resistance R 3 is connected with one end of resistance R 4 connects one end of capacitor C 1, the other end ground connection of capacitor C 1, and the other end of resistance R 4 is connected with one end of capacitor C 2, the other end ground connection of capacitor C 2.
4. the current sampling circuit with temperature drift compensation according to claim 3, it is characterized in that, described current amplification circuit comprises resistance R 5, resistance R 6, capacitor C 3 and amplifier U1, wherein, one end ground connection of described resistance R 5, the other end is connected with one end of resistance R 6, the reverse input end of amplifier U1, and the other end of resistance R 6 is connected with the output terminal of amplifier U1, one end ground connection of capacitor C 3, the other end connects the power end of amplifier U1.
5. the current sampling circuit with temperature drift compensation according to claim 4, is characterized in that, described NTC ratio regulating circuit comprises resistance R 7 and negative tempperature coefficient thermistor R8, one end ground connection of resistance R 8, other end contact resistance R7.
6. according to the current sampling circuit with temperature drift compensation one of claim 1 to 5 Suo Shu, it is characterized in that, described signal follow circuit comprises amplifier U2, and the reverse input end of described amplifier U2 connects its output terminal.
7. the current sampling circuit with temperature drift compensation according to claim 6, is characterized in that, described signal filter circuit comprises resistance R 9 and capacitor C 4, one end ground connection of capacitor C 4, other end contact resistance R9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420202182.6U CN203798845U (en) | 2014-04-23 | 2014-04-23 | Current sampling circuit with temperature drift compensation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420202182.6U CN203798845U (en) | 2014-04-23 | 2014-04-23 | Current sampling circuit with temperature drift compensation |
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| Publication Number | Publication Date |
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| CN203798845U true CN203798845U (en) | 2014-08-27 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201420202182.6U Expired - Lifetime CN203798845U (en) | 2014-04-23 | 2014-04-23 | Current sampling circuit with temperature drift compensation |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104198783A (en) * | 2014-09-19 | 2014-12-10 | 杭州士兰微电子股份有限公司 | Power detection circuit with temperature compensation characteristic and powered device |
| CN107490714A (en) * | 2016-09-14 | 2017-12-19 | 宝沃汽车（中国）有限公司 | Detection method, device and the vehicle of the battery bag charging and discharging currents of vehicle |
| CN109669061A (en) * | 2019-01-31 | 2019-04-23 | 广州金升阳科技有限公司 | A kind of current sample compensation circuit |
-
2014
- 2014-04-23 CN CN201420202182.6U patent/CN203798845U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104198783A (en) * | 2014-09-19 | 2014-12-10 | 杭州士兰微电子股份有限公司 | Power detection circuit with temperature compensation characteristic and powered device |
| CN104198783B (en) * | 2014-09-19 | 2017-08-25 | 杭州士兰微电子股份有限公司 | Power sense circuit and power receiving equipment with temperature compensation characteristic |
| CN107490714A (en) * | 2016-09-14 | 2017-12-19 | 宝沃汽车（中国）有限公司 | Detection method, device and the vehicle of the battery bag charging and discharging currents of vehicle |
| CN109669061A (en) * | 2019-01-31 | 2019-04-23 | 广州金升阳科技有限公司 | A kind of current sample compensation circuit |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 214135, Wuxi New District, Taihu Jiangsu international science and Technology Park, sensor network, University Science and Technology Park, building 530, A902 Patentee after: INTEMOTION TECHNOLOGY WUXI Co.,Ltd. Address before: 214135, Wuxi New District, Taihu Jiangsu international science and Technology Park, sensor network, University Science and Technology Park, building 530, A902 Patentee before: INTEMOTION TECHNOLOGY WUXI Co.,Ltd. |
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| CX01 | Expiry of patent term |
Granted publication date: 20140827 |
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| CX01 | Expiry of patent term |