CN207198222U - A kind of current sampling circuit - Google Patents
A kind of current sampling circuit Download PDFInfo
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- CN207198222U CN207198222U CN201721163339.9U CN201721163339U CN207198222U CN 207198222 U CN207198222 U CN 207198222U CN 201721163339 U CN201721163339 U CN 201721163339U CN 207198222 U CN207198222 U CN 207198222U
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- resistance
- current sampling
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- resistor
- sampling circuit
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Abstract
The utility model discloses a kind of current sampling circuit.This includes：RC filter circuits, wherein, the input of RC filter circuits receives current sampling signal, for being filtered to current sampling signal；Amplifying circuit, wherein, the input of amplifying circuit is connected with the output end of RC filter circuits, for being amplified by the filtered current sampling signal of RC filter circuits, and the current sampling signal after amplification is transmitted to sampler.By the utility model, using circuits below：RC filter circuits and amplifying circuit, solve the problems, such as that current sampling circuit is had a great influence by higher hamonic wave in correlation technique.
Description
Technical field
Current sampling circuit technical field is the utility model is related to, in particular to a kind of current sampling circuit.
Background technology
One of source of current of electric higher hamonic wave is exactly frequently switching on for IPM, current of electric higher harmonic components it is big
The small size that can influence motor torque ripple, higher harmonic components are small, and the torque pulsation of motor is with regard to small, and vice versa.Due to electricity
Electromechanics stream is to be used as an important position estimation parameter, it is desirable to which real-time is high, so in existing current of electric sample circuit
In, if increasing filtering link before operational amplifier, current slow can be caused, can also cause the multiplication factor of amplifier can not change
The problem of, so adding delay compensation on software, when amplifier multiplication factor is different, one is will also result on hardware
Determine the not versatility of degree, and for homologous series or IPM carrier wave identical controllers, versatility can not cause extra
Workload.
For the current sampling circuit in correlation technique, the problem of being had a great influence by higher hamonic wave, not yet propose at present
Effective solution.
Utility model content
Main purpose of the present utility model is to provide a kind of current sampling circuit, to solve current sample in correlation technique
The problem of circuit is had a great influence by higher hamonic wave.
To achieve these goals, according to one side of the present utility model, there is provided a kind of current sampling circuit.The electricity
Road includes：RC filter circuits, wherein, the input of RC filter circuits receives current sampling signal, for current sampling signal
It is filtered；Amplifying circuit, wherein, the input of amplifying circuit is connected with the output end of RC filter circuits, for passing through RC
The filtered current sampling signal of filter circuit is amplified, and the current sampling signal after amplification is transmitted to sampler.
Further, RC filter circuits include：First resistor, wherein, the input and current sampling signal of first resistor
Anode connection；Second resistance, wherein, the input of second resistance and the negative terminal of current sampling signal connect；First electric capacity, its
In, one end of the first electric capacity is connected to first resistor, and the other end of the first electric capacity is connected to second resistance.
Further, according to the resistance of set of frequency first resistor of current sampling signal and the resistance of second resistance and
The capacitance of first electric capacity.
Further, amplifying circuit includes：3rd resistor, wherein, the input of 3rd resistor is connected with first resistor；The
Four resistance, wherein, the input of the 4th resistance is connected with second resistance；5th resistance, wherein, the input of the 5th resistance and
Four resistance connect；Operational amplifier, wherein, opamp input terminal is connected with 3rd resistor and the 4th resistance, operation amplifier
Device output end is connected with the 5th resistance.
Further, according to the resistance of the resistance of 3rd resistor and the 4th resistance, the multiplication factor of operational amplifier is adjusted.
Further, current sampling circuit also includes：6th resistance, wherein, the input and operation amplifier of the 6th resistance
The output end connection of device；Second electric capacity, wherein, second electric capacity one end ground connection, the other end is connected with the 6th resistance.
Further, current sampling circuit also includes：Clamp diode, wherein, the input of clamp diode and the 6th
Resistance is connected, and the output end of clamp diode is connected with sampler, for carrying out pressure limiting to the voltage of input sample device.
Further, according to the load voltage value of sampler, the pressure limiting scope of clamp diode is configured.
To achieve these goals, according to another aspect of the present utility model, there is provided a kind of motor, it is characterised in that
Including above-mentioned current sampling circuit.
To achieve these goals, according to another aspect of the present utility model, there is provided a kind of air-conditioning, it is characterised in that
Including above-mentioned motor.
By the utility model, using circuits below：RC filter circuits and amplifying circuit, solves electric current in correlation technique
The problem of sample circuit is had a great influence by higher hamonic wave, and then eliminate caused by the on-off actions of equipment such as IPM
The effect of higher hamonic wave.
Brief description of the drawings
Form a part of accompanying drawing of the present utility model to be used for providing further understanding to of the present utility model, this practicality is new
The schematic description and description of type is used to explain the utility model, does not form to improper restriction of the present utility model.
In accompanying drawing：
Fig. 1 is the schematic diagram of the current sampling circuit provided according to the utility model embodiment.
Embodiment
It should be noted that in the case where not conflicting, the feature in embodiment and embodiment in the utility model can
To be mutually combined.Describe the utility model in detail below with reference to the accompanying drawings and in conjunction with the embodiments.
In order that those skilled in the art more fully understand the utility model, it is real below in conjunction with the utility model
The accompanying drawing in example is applied, the technical scheme in the embodiment of the utility model is clearly and completely described, it is clear that be described
Embodiment is only the embodiment of the utility model part, rather than whole embodiments.Based on the reality in the utility model
Example is applied, the every other embodiment that those of ordinary skill in the art are obtained under the premise of creative work is not made, all should
When the scope for belonging to the utility model protection.
It should be noted that term " first " in specification and claims of the present utility model and above-mentioned accompanying drawing,
" second " etc. is for distinguishing similar object, without for describing specific order or precedence.It should be appreciated that so
The data used can exchange in the appropriate case, so as to embodiment of the present utility model described herein.In addition, term " bag
Include " and " having " and their any deformation, it is intended that cover it is non-exclusive include, for example, containing series of steps
Or process, system, product or the equipment of unit are not necessarily limited to those steps or the unit clearly listed, but it may include do not have
It is clearly listing or for the intrinsic other steps of these processes, product or equipment or unit.
For the ease of description, the part noun or term being related to below to the utility model embodiment illustrate：
IPM, i.e. SPM, not only integrate device for power switching and drive circuit, and internal collection
Into there are the failure detector circuits such as overvoltage, overcurrent and overheat, and detection signal can be sent to CPU.
According to embodiment of the present utility model, there is provided a kind of current sampling circuit.
Fig. 1 is the schematic diagram according to the current sampling circuit of the utility model embodiment.As shown in figure 1, current sample is electric
Road includes：
RC filter circuits, wherein, the input of RC filter circuits receives current sampling signal, and wherein S+ believes for current sample
Number anode, S- be current sampling signal negative terminal, for being filtered to current sampling signal；Amplifying circuit, wherein, amplification
The input of circuit is connected with the output end of RC filter circuits, for passing through the filtered current sampling signal of RC filter circuits
It is amplified, and the current sampling signal after amplification is transmitted to sampler.
Specifically, RC filter circuits include：First resistor (R11), wherein, the input and electric current of first resistor (R11)
Anode (S+) connection of sampled signal；Second resistance (R12), wherein, the input and current sampling signal of second resistance (R12)
Negative terminal (S-) connection；First electric capacity (C1), wherein, one end of the first electric capacity (C1) is connected to first resistor (R11), the first electricity
The other end for holding (C1) is connected to second resistance (R12)；
In order to improve the filtering accuracy of RC filter circuits, the resistance of first resistor (R11) and second resistance (R12) is being set
And first electric capacity (C1) capacitance when, can be according to the set of frequency of current sampling signal.
Optionally, amplifying circuit includes：3rd resistor (R21), wherein, the input of 3rd resistor (R21) and the first electricity
Hinder (R11) connection；4th resistance (R22), wherein, the input of the 4th resistance (R22) is connected with second resistance (R12)；5th
Resistance (R32), wherein, the input of the 5th resistance (R32) is connected with the 4th resistance (R22)；Operational amplifier, wherein, computing
Amplifier in is connected with 3rd resistor (R21) and the 4th resistance (R22), operational amplifier output terminal and the 5th resistance
(R32) connect.
In order to lift the flexibility of adjustment operational amplifier multiplication factor, optionally, the multiplication factor of operational amplifier needs
The scope of the magnitude of voltage for the signal that can be received according to the size and sampler of the input value of current sampling signal is adjusted,
In actual applications, can be according to the resistance and the resistance of the 4th resistance (R22) of 3rd resistor (R21), to adjust operational amplifier
(U2) multiplication factor.
It should be noted that first resistor (R11) and 3rd resistor (R21) series connection, and second resistance (R12) and the 4th electricity
(R22) series connection is hindered, therefore the resistance for working as 3rd resistor (R21) and the 4th resistance (R22) is fixed, and need to adjust operational amplifier
During U2 multiplication factor, op-amp U2 can be adjusted by adjusting the resistance of first resistor (R11) and second resistance (R12)
Multiplication factor.
Optionally, current sampling circuit also includes：6th resistance (R6), wherein, the input and fortune of the 6th resistance (R6)
Calculate the output end connection of amplifier (U2)；Second electric capacity (C3), wherein, the second electric capacity (C3) one end ground connection, the other end and the 6th
Resistance (R6) connects.
It should be noted that operational amplifier (U2) output amplification after current signal after, the 6th resistance (R6) and
Another filter circuit of second electric capacity (C3) composition is further filtered the high-frequency harmonic included to above-mentioned current signal,
So as to be further ensured that the degree of purity of current sampling signal.
Alternatively, in order to ensure the reliability using the current sampling circuit, current sampling circuit also includes：The pole of clamper two
Manage (D1), wherein, the input of clamp diode (D1) is connected with the 6th resistance (R6), the output end of clamp diode (D1) and
Sampler connects, for carrying out pressure limiting, sampler input (So) to the voltage of input sample device.
Pressure limiting is carried out to the voltage of input sample device by the clamp diode (D1), ensure that the security of sampler,
Further ensure the reliability that circuit is used using the electric current.
Alternatively, according to the load voltage value of sampler, the pressure limiting scope of configuration clamp diode (D1), clamp diode
D1 is made up of two Diode series, wherein, a diode cathode ground connection, another diode cathode connects power Vcc, the
Six resistance (R6) sampler input (So) is connected by the link position of above-mentioned two diode with sampler input (So),
When the value of the current potential current potential above Ground of the signal of input sample device input (So) is more than the reverse breakdown electricity of above-mentioned diode
During pressure, diode reverse breakdown that positive pole is connected to ground, the signal potential of input sample device input (So) is clamped, and voltage is big
The small tube voltage drop for diode reverse breakdown；When the current potential of the signal of input sample device input (So) is less than the electricity of power Vcc
When the value of position is more than the breakdown reverse voltage of above-mentioned diode, diode reverse breakdown that negative pole is connected with power Vcc, input is adopted
The signal potential of sample device input (So) is clamped, and current potential size subtracts the tube voltage drop of above-mentioned diode for the current potential of power Vcc.
Therefore, by configuring the breakdown reverse voltage size of clamp diode (D1), you can configure its pressure limiting scope, and then adopt input
The signal of sample device meets the load voltage value of sampler.
Current sampling circuit in above-described embodiment rearmounted operational amplifier, makes pre-filtering by preposition RC wave filters
Phase shift angle it is small and fixed, not only ensured filtering performance but also do not reduced the real-time of signal, and the phase shift angle of fixation is also just
In compensating.Rearmounted amplifier input resistance not exclusively relies on the R coefficient of wave filter so that and it is adjustable that input resistance becomes part,
The multiplication factor of sampled signal can realize change.
Above-mentioned current sampling circuit phase shift angle is small and fixed, is analyzed as follows：
R11, R12 and C1 form preposition filtering link, mainly eliminate inverter caused high order in action process
Harmonic wave.The cut-off frequency of prefilter can be calculated with below equation：
Tr=4* (2*R1) * C1=8*R1*C1；
Fc=BW=0.35/tr；
Wherein, tr is the rise time, and R1=R11=R12, BW are bandwidth.
The phase shift angle of preposition amplifier can be described with formula below：
Loop complex impedance：Z=R1+ (R1+1/j*2 π f*C1)
Wherein, f is the frequency of sampled signal, and Vo is the output of pre-filtering link, and Vi is the input of pre-filtering link.
It can thus be concluded that lag angle ψ=- arctan (P/Q)；
For example, in the configuration of conventional motor, R1=1.21K, C1=1nf, f=16k are arranged to, is obtained:
Fc=36KHz>F=16K, i.e., useful low frequency signal can pass through；
ψ=- arctan (P/Q)=- arctan (- 0.007/0.9721)=0.0072；
For T=1/f=0.000625s, time delay caused by RC is：T=T* ψ/2* π=0.0011*T<<T；
As can be seen here, in a kind of application of the configuration of conventional motor, prolong in above-mentioned current sampling circuit caused by RC
When the time it is very small, can be neglected in actual applications.
The current sampling circuit that the utility model embodiment provides, pass through preposition RC filter circuits and rearmounted amplification electricity
Road, solve the problems, such as that current sampling circuit is had a great influence by higher hamonic wave in correlation technique, and then elimination IPM etc.
The effect of higher hamonic wave caused by the on-off action of equipment.
The utility model embodiment additionally provides a kind of motor, and the motor includes the current sample electricity described in any of the above-described
Road.
The utility model embodiment additionally provides a kind of air-conditioning, and the air-conditioning includes described motor.
Embodiment of the present utility model is these are only, is not limited to the utility model.For art technology
For personnel, the utility model can have various modifications and variations.It is all to be made within spirit of the present utility model and principle
Any modification, equivalent substitution and improvements etc., it should be included within right of the present utility model.
Claims (10)
- A kind of 1. current sampling circuit, it is characterised in that including：RC filter circuits, wherein, the input of the RC filter circuits receives current sampling signal, for the current sample Signal is filtered；Amplifying circuit, wherein, the input of the amplifying circuit is connected with the output end of the RC filter circuits, for passing through The filtered current sampling signal of RC filter circuits is amplified, and the current sampling signal after amplification is transmitted to sampling Device.
- 2. current sampling circuit according to claim 1, it is characterised in that the RC filter circuits include：First resistor, wherein, the input of the first resistor is connected with the anode of the current sampling signal；Second resistance, wherein, the input of the second resistance is connected with the negative terminal of the current sampling signal；First electric capacity, wherein, one end of first electric capacity is connected to the first resistor, and the other end of first electric capacity connects It is connected to the second resistance.
- 3. current sampling circuit according to claim 2, it is characterised in that according to the set of frequency of current sampling signal institute State the resistance of first resistor and the resistance of second resistance and the capacitance of first electric capacity.
- 4. current sampling circuit according to claim 2, it is characterised in that the amplifying circuit includes：3rd resistor, wherein, the input of the 3rd resistor is connected with the first resistor；4th resistance, wherein, the input of the 4th resistance is connected with the second resistance；5th resistance, wherein, the input of the 5th resistance is connected with the 4th resistance；Operational amplifier, wherein, the opamp input terminal is connected with the 3rd resistor and the 4th resistance, described Operational amplifier output terminal is connected with the 5th resistance.
- 5. current sampling circuit according to claim 4, it is characterised in that according to the resistance of the 3rd resistor and the 4th The resistance of resistance, adjust the multiplication factor of the operational amplifier.
- 6. current sampling circuit according to claim 4, it is characterised in that current sampling circuit also includes：6th resistance, wherein, the input of the 6th resistance is connected with the output end of the operational amplifier；Second electric capacity, wherein, the second electric capacity one end ground connection, the other end is connected with the 6th resistance.
- 7. current sampling circuit according to claim 6, it is characterised in that current sampling circuit also includes：Clamp diode, wherein, the input of the clamp diode is connected with the 6th resistance, the clamp diode Output end is connected with the sampler, for carrying out pressure limiting to the voltage for inputting the sampler.
- 8. current sampling circuit according to claim 7, it is characterised in that according to the load voltage value of the sampler, Configure the pressure limiting scope of the clamp diode.
- 9. a kind of motor, it is characterised in that including the current sampling circuit any one of claim 1 to 8.
- 10. a kind of air-conditioning, it is characterised in that including the motor described in claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721163339.9U CN207198222U (en) | 2017-09-11 | 2017-09-11 | A kind of current sampling circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721163339.9U CN207198222U (en) | 2017-09-11 | 2017-09-11 | A kind of current sampling circuit |
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| Publication Number | Publication Date |
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| CN207198222U true CN207198222U (en) | 2018-04-06 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113848399A (en) * | 2020-06-28 | 2021-12-28 | 广东威特真空电子制造有限公司 | Microwave oven and magnetron detection device |
-
2017
- 2017-09-11 CN CN201721163339.9U patent/CN207198222U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113848399A (en) * | 2020-06-28 | 2021-12-28 | 广东威特真空电子制造有限公司 | Microwave oven and magnetron detection device |
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