CN207234388U - A kind of novel bus current foldback circuit - Google Patents
A kind of novel bus current foldback circuit Download PDFInfo
- Publication number
- CN207234388U CN207234388U CN201721216064.0U CN201721216064U CN207234388U CN 207234388 U CN207234388 U CN 207234388U CN 201721216064 U CN201721216064 U CN 201721216064U CN 207234388 U CN207234388 U CN 207234388U
- Authority
- CN
- China
- Prior art keywords
- resistance
- low
- pass filter
- pin
- foldback circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
Overcurrent protection field is the utility model is related to, discloses a kind of novel bus current foldback circuit.Sampling resistor is in series with the busbar；The current foldback circuit includes sequentially connected low-pass filter, partial pressure unit, current sample comparator；The low-pass filter is in parallel with sampling resistor；The external microcontroller of output terminal of the current sample comparator.The utility model circuit structure is simple, of less demanding to components accuracy, cost is low, strong antijamming capability while, sampling precision Gao Bingneng effectively plays the effect of overcurrent protection.
Description
Technical field
Current protection technology field is the utility model is related to, more particularly, to a kind of novel bus current foldback circuit.
Background technology
In motor bus current sample circuit, bus current produces pressure drop by sampling resistor, due to usual busbar electricity
Stream is all more than 100 amperes, according to P=I2R, therefore it is required that the resistance value of sampling resistor is very small, otherwise can produce very big
Power attenuation.Because sampling resistor resistance value is very small, differential signal BUSS, BUSSG of inlet highway current foldback circuit nor
It is often faint.
Traditional circuit is the size for accurately sampling out bus current, then calculates busbar by the programmed algorithm in microcontroller
Electric current whether exceed setting value, so as to judge whether to need to carry out protection act.As shown in Figure 1, its implementation is：Pass through
OP amplifiers are sent into the tiny differential signal collected after two level is amplified the size that main control unit carries out calculating current.
There are following shortcoming for the prior art：
The maximum feature of one of prior art circuits is that OP amplifiers introduce two level negative-feedback, therefore it is required that R7=R11=R13
The error that=R15, R8=10*R9=10*R14, slightly deviation may result in output result is very big, therefore in the prior art to this
The required precision of several resistance is very high；The precision of resistance is difficult to reach, and causes the sampling precision of the program not high；And this circuit
Complexity, antijamming capability is weak, and reliability is low.
Utility model content
The utility model is at least one defect overcome described in the above-mentioned prior art, there is provided a kind of circuit structure is simple,
While, strong antijamming capability of less demanding to components accuracy, sampling precision Gao Bingneng effectively plays the new mother of overcurrent protection
Line current foldback circuit.
In order to solve the above technical problems, the technical solution of the utility model is as follows：
A kind of novel bus current foldback circuit is provided, sampling resistor is in series with the busbar；The overcurrent protection electricity
Road includes sequentially connected low-pass filter, partial pressure unit, current sample comparator；The low-pass filter and sampling resistor
It is in parallel；The external microcontroller of output terminal of the current sample comparator.
By setting low-pass filter in the application, the High-frequency Interference on busbar is filtered out；Exported by adjusting partial pressure unit
Magnitude of voltage to be used as busbar overcurrent protection threshold value.After the faint differential signal collected is by low-pass filter, with partial pressure list
The output protection threshold value of member is compared；If exceeding threshold value, current sample comparator will export a signal to microcontroller,
Microcontroller need not calculate can make corresponding overcurrent protection action with signal accordingly.
Preferably, the low-pass filter uses resistance capacitance formula.
It is further preferred that the low-pass filter includes resistance R1, resistance R2, resistance R3 and capacitance C1；Resistance R3
Parallel with one another with capacitance C1, the both ends of resistance R3 are connected to resistance R1 and resistance R2, and resistance R1 and resistance R2 are not connected with electricity
The one end for hindering R3 is connected as the input terminal of low-pass filter and the both ends of sampling resistor, and the both ends of the capacitance C1 are as low pass
The output terminal of wave filter is connected with current sample comparator.
Preferably, the current sample comparator uses current sample comparable chip.
It is further preferred that the current sample comparable chip uses AD8214 chips.This chip periphery circuit is simple, valency
Lattice are cheap.
Preferably, the partial pressure unit includes resistance R4 and resistance R5；Can by the resistance value of regulation resistance R4 and resistance R5
To adjust the rotection thresholds of partial pressure unit output；The pin Vs of the AD8214 chips connects power supply；Pin+IN passes through parallel with one another
Filter capacitor C2 and an output terminal of divider resistance R4 and low-pass filter connection；Another output terminal of low-pass filter
It is connected with pin-IN；Pin Vreg is connected by resistance R5 with pin+IN；Pin GND is grounded；Pin OUT is connect by resistance R6
Ground, and by protection diode D1 connection power supplys, while output terminal external microcontrollers of the pin OUT as current sample comparator
Device.
Further, the microcontroller is microcontroller.
The beneficial effects of the utility model：
The application eliminates the negative feedback network that the prior art uses, and circuit structure is simple, is easy to commercialization；Pass through low pass
Wave filter realizes anti-interference, and by setting partial pressure unit, sample rate current and current protection threshold are realized using electric current comparable chip
Value carries out electric current comparison, solves tiny signal fluctuation and is also easy to produce the influence of large error, it is necessary to uses high-precision resistance, of high cost
The problem of；Meanwhile external microcontroller need not calculate and can make corresponding protection act with signal accordingly, solve
The problem of circuit is complicated.
This current foldback circuit, not only can be adapted for busbar overcurrent protection, same for the overcurrent protection on All other routes
Sample is applicable in.
Brief description of the drawings
Fig. 1 is existing current foldback circuit structure diagram.
Fig. 2 is 1 electrical block diagram of embodiment.
Embodiment
Attached drawing is only for illustration, it is impossible to is interpreted as the limitation to this patent；
In order to more preferably illustrate the present embodiment, some components of attached drawing have omission, zoom in or out, and do not represent actual product
Size；To those skilled in the art, some known features and its explanation may be omitted and will be understood by attached drawing.
For the ordinary skill in the art, concrete meaning of the above-mentioned term in the utility model can be understood with concrete condition.
The technical solution of the utility model is described further with reference to the accompanying drawings and examples.
Embodiment 1
As shown in Figure 1, in the prior art, the tiny differential signal collected is sent after two level is amplified by OP amplifiers
Enter the size that main control unit carries out calculating current.In this circuit in order to ensure sampling accuracy, R7=R11=R13=R15, R8=
10*R9=10*R14, the required precision to resistance are excessive, it is difficult to realize commercialization.And two level reversed feedback amplifier is introduced, electricity
Road is complicated, very high to the susceptibility of tiny signal, and extraneous minimum interference can also produce final output result bigger shadow
Ring.
As shown in Fig. 2, in view of the shortcomings of the prior art, the present embodiment provides a kind of novel bus current foldback circuit.This
Embodiment is to be applied to electric power steering（EPS）Exemplified by technical field.Sampling resistor is in series with EPS motor busbar；Overcurrent
Circuit is protected to include sequentially connected low-pass filter, partial pressure unit, current sample comparator；Low-pass filter with sampling electricity
Resistance is in parallel；The external microcontroller of output terminal of the current sample comparator.
The low-pass filter that the present embodiment uses includes resistance R1, resistance R2, resistance R3 and capacitance C1；Resistance R3 and electricity
Appearance C1 is parallel with one another, and the both ends of resistance R3 are connected to resistance R1 and resistance R2, and resistance R1 and resistance R2 are not connected with resistance R3
One end as low-pass filter input terminal and sampling resistor both ends connect, the both ends of the capacitance C1 are as low-pass filtering
The output terminal of device is connected with current sample comparator.One end that resistance R1 is not connected with resistance R3 is also associated with busbar power supply 12V.
The current sample comparator of the present embodiment is using the electric current that peripheral circuit is simple, common-mode rejection ratio is big, cheap
Comparable chip AD8214 chips are sampled to realize.
Partial pressure unit includes resistance R4 and resistance R5；The pin Vs of AD8214 chips meets power supply 12V；Pin+IN passes through phase
Mutually filter capacitor C2 in parallel and the connection of an output terminal of divider resistance R4 and low-pass filter；Low-pass filter another
Output terminal is connected with pin-IN；Pin Vreg is connected by resistance R5 with pin+IN；Pin GND is grounded；Pin OUT passes through electricity
R6 ground connection is hindered, and by protection diode D1 connection power supply 5V, while outside output terminals of the pin OUT as current sample comparator
Connect microcontroller.
In the present embodiment the output protection threshold value of partial pressure unit is set by setting the resistance value of resistance R4 and resistance R5.Adopt
After the faint differential signal collected is by low-pass filter, with resistance R4, the output protection threshold of the partial pressure unit of resistance R5 compositions
Value is compared, if exceeding threshold value, the 5 foot pin OUT of AD8214 chips U1 export a high level signal to external monolithic
Machine, microcontroller, which need not calculate, to make corresponding protection act with signal accordingly.
The present embodiment circuit structure is simple, and cost is low, and sampling precision is high, can effectively carry out overcurrent protection.
The present embodiment has already been through EMC electromagnetic interference experiment tests, and is successfully applied on EPS volume production controllers.
The same or similar label correspond to the same or similar components；Described in attached drawing position relationship be used for be only used for showing
Example property explanation, it is impossible to be interpreted as the limitation to this patent.Obviously, above-described embodiment of the utility model is only clearly to say
Bright the utility model example, and it is not the restriction to the embodiment of the utility model.For the general of fields
For logical technical staff, other different forms of changes or modifications may be made based on the above description.Here need not
Also all embodiments can not be exhaustive.Any modification for being made where within the spirit and principles of the present invention,
Equivalent substitution and improvement etc., should be included within the utility model scope of the claims.
Claims (7)
1. a kind of novel bus current foldback circuit, sampling resistor is in series with the busbar；It is characterized in that, the overcurrent is protected
Protection circuit includes sequentially connected low-pass filter, partial pressure unit, current sample comparator；The low-pass filter with sampling
Resistor coupled in parallel；The external microcontroller of output terminal of the current sample comparator.
2. novel bus current foldback circuit according to claim 1, it is characterised in that the low-pass filter uses resistance
Condenser type.
3. novel bus current foldback circuit according to claim 2, it is characterised in that the low-pass filter includes resistance
R1, resistance R2, resistance R3 and capacitance C1；Resistance R3 and capacitance C1 are parallel with one another, and the both ends of resistance R3 are connected to resistance
R1 and resistance R2, resistance R1 and resistance R2 are not connected with the input terminal and sampling resistor of one end of resistance R3 as low-pass filter
Both ends connect, and the both ends of the capacitance C1 are connected as the output terminal of low-pass filter with current sample comparator.
4. according to novel bus current foldback circuit described in claims 1 to 3 any one, it is characterised in that the electric current is adopted
Sample comparator uses current sample comparable chip.
5. novel bus current foldback circuit according to claim 4, it is characterised in that the current sample comparable chip is adopted
With AD8214 chips.
6. novel bus current foldback circuit according to claim 5, it is characterised in that the partial pressure unit includes resistance R4
With resistance R5；The pin Vs of the AD8214 chips connects power supply；Pin+IN passes through filter capacitor C2 parallel with one another and partial pressure electricity
An output terminal for hindering R4 and low-pass filter connects；Another output terminal of low-pass filter is connected with pin-IN；Pin
Vreg is connected by resistance R5 with pin+IN；Pin GND is grounded；Pin OUT is grounded by resistance R6, and by protecting two poles
Pipe D1 connection power supplys, while output terminal external microcontrollers of the pin OUT as current sample comparator.
7. according to the novel bus current foldback circuit of claim 5 or 6, it is characterised in that the microcontroller is monolithic
Machine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721216064.0U CN207234388U (en) | 2017-09-21 | 2017-09-21 | A kind of novel bus current foldback circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721216064.0U CN207234388U (en) | 2017-09-21 | 2017-09-21 | A kind of novel bus current foldback circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207234388U true CN207234388U (en) | 2018-04-13 |
Family
ID=61863483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721216064.0U Active CN207234388U (en) | 2017-09-21 | 2017-09-21 | A kind of novel bus current foldback circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207234388U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109921398A (en) * | 2019-03-21 | 2019-06-21 | 广东美的制冷设备有限公司 | Current foldback circuit and air conditioner |
| CN110474304A (en) * | 2019-07-23 | 2019-11-19 | 上海空间电源研究所 | A kind of Magnetic isolation formula high voltage bus high-speed response current foldback circuit |
-
2017
- 2017-09-21 CN CN201721216064.0U patent/CN207234388U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109921398A (en) * | 2019-03-21 | 2019-06-21 | 广东美的制冷设备有限公司 | Current foldback circuit and air conditioner |
| CN110474304A (en) * | 2019-07-23 | 2019-11-19 | 上海空间电源研究所 | A kind of Magnetic isolation formula high voltage bus high-speed response current foldback circuit |
| CN110474304B (en) * | 2019-07-23 | 2021-09-07 | 上海空间电源研究所 | Magnetic isolation type high-speed response overcurrent protection circuit for high-voltage bus |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103954821A (en) | Ripple voltage detection method of filer capacitor equivalent series resistor | |
| CN102967748A (en) | DC bus voltage detection circuit with high antijamming capability | |
| CN207234388U (en) | A kind of novel bus current foldback circuit | |
| CN105162314B (en) | A kind of over-current detection circuit for BUCK converters | |
| CN107219402B (en) | A kind of circuit for quick measurement of DC resistance for power module port | |
| CN103698600A (en) | Frequency measuring system for universal voltage input power frequency signal | |
| CN103675421A (en) | Power burr signal detection circuit and detection method thereof | |
| CN103441482A (en) | Current monitoring circuit with accurate current-limit function | |
| CN204964613U (en) | Zero -cross detection circuit | |
| CN103546114B (en) | Circuit according to pull-up voltage in the pull-up Voltage Cortrol bus of equipment and method thereof | |
| CN206618791U (en) | A kind of wide-band capacitor compensating formula resitstance voltage divider | |
| CN114624497A (en) | Vehicle-mounted equipment input large current detection circuit structure | |
| CN109581043A (en) | A kind of high direct voltage signal acquisition circuit | |
| CN105223533A (en) | A kind of superhigh precision responds DC current prover circuit fast | |
| CN103647447B (en) | The supply unit of a kind of electric energy table communication module | |
| CN103236679B (en) | Exchange breaker electronic type standby protector | |
| CN106410757A (en) | Short-circuit protective circuit | |
| CN206096239U (en) | Reference voltage sample module, signal processing device and converter | |
| CN209117756U (en) | Fan monitor | |
| CN209559957U (en) | A kind of steering engine current detection circuit and system | |
| CN208766550U (en) | A kind of constant current drawing, which carries, sets | |
| CN206117132U (en) | Leakage current protector circuit based on ARM platform | |
| CN205691660U (en) | A kind of power input to a machine counting circuit | |
| CN204440215U (en) | A kind of adjustable DC constant current source generation device based on microcontroller | |
| CN215956371U (en) | Analog quantity sampling conditioning circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210203 Address after: 412000 Room 201, 100 Hangkong Road, Lusong District, Zhuzhou City, Hunan Province Patentee after: Hunan Dongjia Intelligent Technology Co.,Ltd. Address before: 412000 No.100 Hangkong Avenue, high tech park, Dongjia section, Lusong District, Zhuzhou City, Hunan Province Patentee before: ZHUZHOU ELITE ELECTRO MECHANICAL Co.,Ltd. |
|
| TR01 | Transfer of patent right |