CN203011991U - Current sampling circuit and motor - Google Patents
Current sampling circuit and motor Download PDFInfo
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- CN203011991U CN203011991U CN2012206780018U CN201220678001U CN203011991U CN 203011991 U CN203011991 U CN 203011991U CN 2012206780018 U CN2012206780018 U CN 2012206780018U CN 201220678001 U CN201220678001 U CN 201220678001U CN 203011991 U CN203011991 U CN 203011991U
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- sampling resistor
- current sampling
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Abstract
The utility model provides a current sampling circuit and a motor. The current sampling circuit comprises a sampling resistor the first end of which receives a sampling current. The current sampling circuit further comprises a compensating circuit connected with the sampling resistor in a parallel way. The compensating circuit comprises a direct current source. The direct current source is connected to the first end of a divider resistor. The second end of the divider resistor is connected to a first voltage dividing branch and a second voltage dividing branch which are connected in a parallel way. The second end of the divider resistor outputs a sampling voltage. The motor comprises a stator and a rotor. The motor is further provided with a controller. The controller comprises a control module and a power drive circuit receiving signals output from the control module. The controller further comprises the above-mentioned current sampling circuit. The current sampling circuit can increase the value of the output sampling voltage and prevent the output voltage value from working in a non-linear zone of an amplification zone. The control module is thus made to precisely calculate the running state of the motor and further ensures precise control on the motor.
Description
Technical field
The utility model relates to machine field, the motor that especially relates to a kind of current sampling circuit of motor and have this current sampling circuit.
Background technology
Brshless DC motor possesses the advantage of continuous speed adjustment because of it, more and more is subject to people's favor, has been widely used in various electric equipments.Brshless DC motor has stator and can be with respect to the rotor of stator rotation, and is provided with a controller that is used for controlling machine operation, and the structured flowchart of controller as shown in Figure 1.
Controller has control module 11, and control module 11 normally single-chip microcomputer, DSP, Electric Machine Control special chip etc. can externally be exported the device of control signal, and it receives the control signal of outside input.Control module 11 is according to the control signal production burst modulation signal that receives, i.e. pwm signal, and export the pwm signal that generates to power driving circuit 12.
Power driving circuit 12 has a plurality of controlled field effect transistor, each field effect transistor can be under the control of pwm signal break-make, and to the motor M output drive signal, drive motor work, and drive armature spindle rotation, outwards outputting power by rotor.
Controller also has a current sampling circuit 13, current signal for detection of the stator of flowing through, and convert current signal to voltage signal and export amplifier U1 to, amplifier U1 exports control module 11 to after current signal is amplified, and control module 11 is according to the rotating speed of the judgement rotors such as the amplitude of current signal, phase place, angle etc.
Referring to Fig. 2, current sampling circuit 13 has sampling resistor R11, and the end of sampling resistor R11 is connected to current sample terminal IN, is used for receiving sample rate current, the other end ground connection of sampling resistor R11.Sample rate current is flowed through and is formed sampled voltage after sampling resistor R11, and sampled voltage exports amplifier U1 to, and amplifier U1 exports control module 11 to after sampled voltage is amplified.
But, existing amplifier U1 is generally integrated operational amplifier, and its linearity is usually undesirable, can't guarantee the consistance of enlargement factor in namely between whole amplification region, normally the phenomenon that enlargement factor increases suddenly appears near the zone its supply voltage, causes the amplified curve distortion.
Shown in Figure 3 is the amplified curve of common integrated operational amplifier, and its transverse axis represents the input voltage amplitude, and the longitudinal axis is output voltage amplitude, and the supply voltage of this amplifier is 40 millivolts.As seen from Figure 3, amplifier U1 to the input the voltage signal enlargement factor usually 20 times of left and right, but at input voltage between 39 millivolts to 40 millivolts, enlargement factor increases to suddenly 29 times, then returns to rapidly 20 times.
Like this, the sampled voltage of current sampling circuit 13 output 39 millivolts to 40 between the time, the magnitude of voltage of amplifier U1 output increases suddenly, the voltage of namely current sampling circuit 13 outputs includes the part in the inelastic region, cause control module 11 can't accurately calculate the current value of the stator of flowing through, the ruuning situation that can not accurately reflect motor also just can't accurately be controlled the operation of motor.
Summary of the invention
Fundamental purpose of the present utility model is to provide the current sampling circuit that a kind of voltage signal of avoiding exporting is operated in the inelastic region.
Another purpose of the present utility model is to provide a kind ofly guarantees that controller accurately controls the motor of its operation.
For realizing fundamental purpose of the present utility model, the current sampling circuit that the utility model provides comprises sampling resistor, the first end of sampling resistor receives sample rate current, and, current sampling circuit also comprises the compensating circuit that is connected in parallel with sampling resistor, and compensating circuit has direct supply, and direct supply is connected to the first end of divider resistance, the second end of divider resistance is connected to the first dividing potential drop branch road and the second dividing potential drop branch road that is connected in parallel, the second end output sampled voltage of divider resistance.
By such scheme as seen, current sampling circuit arranges compensating circuit, the direct supply of compensating circuit provides a voltage signal by divider resistance, output to amplifier after the voltage that sample rate current process sampling resistor forms and the stack of the voltage after the divider resistance dividing potential drop, thereby improve the magnitude of voltage of current sampling circuit output, avoid the magnitude of voltage of current sampling circuit output to be positioned at the amplifier nonlinearity workspace, and then guarantee that amplifier is linear the amplification to the voltage signal of input, control module can accurately be controlled motor.
A preferred scheme is that compensating circuit also has the filter capacitor that is connected in parallel with sampling resistor.
This shows, compensating circuit arranges filter capacitor, and the voltage signal that sampling resistor is exported carries out filtering, makes the sampled voltage signal of current sampling circuit output more steady.
Further scheme is, the first dividing potential drop branch road has the first resistance that is connected in series with sampling resistor, and the second dividing potential drop branch road has the second resistance, and the resistance of the first resistance equates with the resistance of the second resistance.
As seen, because the resistance value of the first resistance with the second resistance equates, the magnitude of voltage of such the first dividing potential drop branch road and the second dividing potential drop branch road is avoided occurring two different excessive situations of dividing potential drop branch voltage value difference and is occured also about equally.
Further scheme is, the resistance of the first resistance is greater than the resistance of sampling resistor, and the resistance of divider resistance is greater than the resistance of the first resistance.
for realizing another purpose of the present utility model, the motor that the utility model provides comprises stator and rotor, and be provided with controller, the power driving circuit that controller has control module and receives the control module output signal, controller also has sample streams through the current sampling circuit of stator current, the output terminal of current sampling circuit is connected with amplifier and exports sampled signal to amplifier, current sampling circuit has sampling resistor, the first end of sampling resistor receives sample rate current, and, current sampling circuit also comprises the compensating circuit that is connected in parallel with sampling resistor, compensating circuit has direct supply, direct supply is connected to the first end of divider resistance, the second end of divider resistance is connected to the first dividing potential drop branch road and the second dividing potential drop branch road that is connected in parallel, the second end output sampled voltage of divider resistance.
By such scheme as seen, the compensating circuit of current sampling circuit setting can provide a voltage signal that is used for increasing output voltage values, the magnitude of voltage stack that this voltage and sample rate current are flowed through and formed after sampling resistor, and form sampled voltage output, sample voltage value is higher like this, can avoid the magnitude of voltage of current sampling circuit output in the amplifier nonlinearity workspace, amplifier carries out the linearity amplification to the voltage signal of input, accurately the ruuning situation of reflection motor, be conducive to control module to the accurate control of motor.
Description of drawings
Fig. 1 is the electric theory diagram of existing electric machine controller.
Fig. 2 is the electrical schematic diagram of current sampling circuit and amplifier in existing electric machine controller.
Fig. 3 is the characteristic working curve schematic diagram of amplifier.
Fig. 4 is the electrical schematic diagram of the utility model current sampling circuit embodiment.
The utility model is described in further detail below in conjunction with drawings and Examples.
Embodiment
The motor of the present embodiment has a housing, and stator and rotor are installed in housing, also is provided with on motor for the controller of controlling machine operation, and controller has control module, power driving circuit and current sampling circuit.Wherein control module is the devices such as single-chip microcomputer, DSP or Electric Machine Control special chip, power driving circuit has a plurality of field effect transistor, conducting or the cut-off under the signal controlling of control module output of each field effect transistor, current sampling circuit is used for sample streams through the current signal of stator, and with the signal feedback of sampling to control module.
Referring to Fig. 4, the current sampling circuit of the present embodiment has sampling resistor R1, and the end of sampling resistor R1 is connected to the sub-IN of current input terminal, receives sample rate current, the other end ground connection of sampling resistor R1.Sample rate current forms voltage V1 on sampling resistor R1 after the sub-IN of current output terminal flows through.
Current sampling circuit also has compensating circuit, compensating circuit and sampling resistor R1 are connected in parallel, it is comprised of resistance R 2, R3, R4 and capacitor C 1, resistance R 3 is divider resistance, the one end is connected to direct supply VCC, as the low-voltage dc power supply of 5 volts, the second end of resistance R 3 is connected to the lead-out terminal OUT of current sampling circuit, to amplifier output sampled voltage.In the present embodiment, the second terminal voltage value of setting divider resistance R3 is V2, namely the output voltage values of current sampling circuit.
Resistance R 2 is connected in series with sampling resistor R1, it consists of a dividing potential drop branch road, resistance R 4 is connected with the first dividing potential drop branch circuit parallel connection, it consists of the second dividing potential drop branch road, therefore the first dividing potential drop branch road is connected with the second dividing potential drop branch circuit parallel connection, and the second end of divider resistance R4 is connected to the first dividing potential drop branch road and the second dividing potential drop branch road.
Capacitor C 1 is filter capacitor, and itself and sampling resistor R1 are connected in parallel, and is used for voltage signal V1 is carried out filtering, guarantees that the voltage signal of current sampling circuit output is steady.
In the present embodiment, the magnitude of voltage of sampling resistor R1 is 0.16 Europe, resistance R 2 equates with the resistance value of resistance R 4, be 1 kilo-ohm, the resistance value of divider resistance R3 is maximum, be 47 kilo-ohms, namely the resistance value of divider resistance R3 is much larger than the resistance value of resistance R 2, and the resistance value of resistance R 2 is also much larger than the resistance value of sampling resistor R1.
As seen from Figure 4, the current sampling circuit common property is given birth to the two-way voltage signal, and one the tunnel is the sample rate current voltage signal that sample circuit obtains of flowing through.Due in parallel with sampling resistor R1 again after 4 series connection of resistance R 2 and resistance R, the sample rate current ground connection after this parallel circuit of flowing through obtains first voltage signal V1.Due to the series circuit resistance of resistance R 2 and resistance R 4 resistance value much larger than sampling resistor R1, can ignore when in parallel, so voltage signal V1 is approximately equal to the sample rate current resistance value with sampling resistor R1 on duty.
Another road voltage signal is the compensation voltage signal that the direct supply VCC of 5 volts obtains through electric resistance partial pressure.Due to sampling resistor R1 and resistance R 2 series connection, more in parallel with resistance R 4, equivalent resistance in parallel is connected with divider resistance R3, and the direct supplys of 5 volts are carried out dividing potential drop, is compensated voltage.Because of the resistance value of the sampling resistor R1 resistance value much smaller than resistance R 2, can ignore during series connection.The voltage that compensating circuit produces and voltage signal V1 stack obtain voltage signal V2, and voltage signal V2 is input to the sampled voltage that amplifier amplifies operation.
Through simplifying, the magnitude of voltage of voltage signal V2 can calculate by following formula and obtain:
The enlargement factor of supposing the amplifier normal operation is N, and the voltage signal after amplification is V3, has
As seen, although the voltage signal of amplifier output is V3, reflect that wherein the amount of size of current is
Because the resistance that adopts resistance R 1, resistance R 2, divider resistance R3 and resistance R 4 is fixed value, and the enlargement factor N of amplifier is also fixed value, therefore, after control module receives voltage signal V3, the calculating of through type 2, the amount of reflection size of current can be calculated, then according to the actual enlargement factor N of amplifier, the size of stator current can be calculated.
As seen, current sampling circuit is by arranging compensating circuit, sample rate current is flowed through export again amplifier to after voltage signal after sampling resistor compensates, the input signal of avoiding being input to amplifier is too small and be operated in the inelastic region, thereby the voltage signal of guaranteeing amplifier output is all linear voltage signals that amplify, and control module can accurately be controlled motor.
It is emphasized that at last the utility model is not limited to above-mentioned embodiment, also should be included in the protection domain of the utility model claim as the change of the resistance value of each resistance, the variations such as capacitance change of electric capacity.
Claims (10)
1. current sampling circuit, comprise
Sampling resistor, the first end of described sampling resistor receives sample rate current;
It is characterized in that:
Also comprise the compensating circuit that is connected in parallel with described sampling resistor, described compensating circuit has direct supply, described direct supply is connected to the first end of divider resistance, the second end of described divider resistance is connected to the first dividing potential drop branch road and the second dividing potential drop branch road that is connected in parallel, the second end output sampled voltage of described divider resistance.
2. current sampling circuit according to claim 1 is characterized in that:
Described compensating circuit also has the filter capacitor that is connected in parallel with described sampling resistor.
3. current sampling circuit according to claim 1 and 2 is characterized in that:
Described the first dividing potential drop branch road has the first resistance that is connected in series with described sampling resistor, and described the second dividing potential drop branch road has the second resistance, and the resistance of described the first resistance equates with the resistance of described the second resistance.
4. current sampling circuit according to claim 3 is characterized in that:
The resistance of described the first resistance is greater than the resistance of described sampling resistor.
5. current sampling circuit according to claim 3 is characterized in that:
The resistance of described divider resistance is greater than the resistance of described the first resistance.
6. motor, comprise
Stator and rotor, and be provided with controller, described controller has
Control module and the power driving circuit that receives described control module output signal, described controller also has sample streams through the current sampling circuit of described stator current, the output terminal of described current sampling circuit is connected with amplifier and exports sampled signal to described amplifier, described current sampling circuit has sampling resistor, and the first end of described sampling resistor receives sample rate current;
It is characterized in that:
Described current sampling circuit also comprises the compensating circuit that is connected in parallel with described sampling resistor, described compensating circuit has direct supply, described direct supply is connected to the first end of divider resistance, the second end of described divider resistance is connected to the first dividing potential drop branch road and the second dividing potential drop branch road that is connected in parallel, the second end output sampled voltage of described divider resistance.
7. motor according to claim 6 is characterized in that:
Described compensating circuit also has the filter capacitor that is connected in parallel with described sampling resistor.
8. according to claim 6 or 7 described motors is characterized in that:
Described the first dividing potential drop branch road has the first resistance that is connected in series with described sampling resistor, and described the second dividing potential drop branch road has the second resistance, and the resistance of described the first resistance equates with the resistance of described the second resistance.
9. motor according to claim 8 is characterized in that:
The resistance of described the first resistance is greater than the resistance of described sampling resistor.
10. motor according to claim 8 is characterized in that:
The resistance of described divider resistance is greater than the resistance of described the first resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012206780018U CN203011991U (en) | 2012-12-10 | 2012-12-10 | Current sampling circuit and motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012206780018U CN203011991U (en) | 2012-12-10 | 2012-12-10 | Current sampling circuit and motor |
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| CN203011991U true CN203011991U (en) | 2013-06-19 |
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| CN2012206780018U Expired - Fee Related CN203011991U (en) | 2012-12-10 | 2012-12-10 | Current sampling circuit and motor |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103344811A (en) * | 2013-06-27 | 2013-10-09 | 浙江联宜电机股份有限公司 | Current detecting circuit of direct-current motor |
| CN106154012A (en) * | 2015-04-08 | 2016-11-23 | 贺遒翔 | A kind of current sensing means and method |
| CN108880497A (en) * | 2018-09-10 | 2018-11-23 | 四川湖山电器股份有限公司 | A kind of self-adapting load audio power amplifying circuit |
| CN108933552A (en) * | 2018-06-04 | 2018-12-04 | 青岛海尔智能电子有限公司 | Variable-frequency motor current sampling circuit and frequency conversion equipment |
| CN111322233A (en) * | 2020-02-28 | 2020-06-23 | 珠海格力电器股份有限公司 | Sampling circuit and method for improving precision, compressor and air conditioning equipment |
| CN111751597A (en) * | 2020-06-23 | 2020-10-09 | 四川虹美智能科技有限公司 | Current sampling circuit and motor |
| CN114137293A (en) * | 2021-11-02 | 2022-03-04 | 中国航空工业集团公司洛阳电光设备研究所 | Direct current torque motor current detection circuit with isolation function |
-
2012
- 2012-12-10 CN CN2012206780018U patent/CN203011991U/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103344811A (en) * | 2013-06-27 | 2013-10-09 | 浙江联宜电机股份有限公司 | Current detecting circuit of direct-current motor |
| CN103344811B (en) * | 2013-06-27 | 2016-06-08 | 浙江联宜电机股份有限公司 | A kind of DC motor current detection circuit |
| CN106154012A (en) * | 2015-04-08 | 2016-11-23 | 贺遒翔 | A kind of current sensing means and method |
| CN108933552A (en) * | 2018-06-04 | 2018-12-04 | 青岛海尔智能电子有限公司 | Variable-frequency motor current sampling circuit and frequency conversion equipment |
| CN108880497A (en) * | 2018-09-10 | 2018-11-23 | 四川湖山电器股份有限公司 | A kind of self-adapting load audio power amplifying circuit |
| CN108880497B (en) * | 2018-09-10 | 2023-08-29 | 四川湖山电器股份有限公司 | Self-adaptive load audio power amplifying circuit |
| CN111322233A (en) * | 2020-02-28 | 2020-06-23 | 珠海格力电器股份有限公司 | Sampling circuit and method for improving precision, compressor and air conditioning equipment |
| CN111751597A (en) * | 2020-06-23 | 2020-10-09 | 四川虹美智能科技有限公司 | Current sampling circuit and motor |
| CN114137293A (en) * | 2021-11-02 | 2022-03-04 | 中国航空工业集团公司洛阳电光设备研究所 | Direct current torque motor current detection circuit with isolation function |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130619 Termination date: 20211210 |
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| CF01 | Termination of patent right due to non-payment of annual fee |