CN2881654Y - Current detection circuit - Google Patents
Current detection circuit Download PDFInfo
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- CN2881654Y CN2881654Y CN 200620000753 CN200620000753U CN2881654Y CN 2881654 Y CN2881654 Y CN 2881654Y CN 200620000753 CN200620000753 CN 200620000753 CN 200620000753 U CN200620000753 U CN 200620000753U CN 2881654 Y CN2881654 Y CN 2881654Y
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Abstract
The utility model discloses a current detection circuit, including a voltage-controlled current source, a current sampling circuit and a transformer. Through the sampling signal, access to the original switching current signal, the current signal of the output induction is controlled, synthesized and simulated by the voltage-controlled current source, thus obtains the current signal that is very close to the actual output current signal. The utility model has the characteristics such as simple circuit, low cost; small size, low power consumption, high reliability and so on.
Description
Technical field
The utility model relates to a kind of current detection circuit, specifically, relates to a kind of current detection circuit of applied current synthetic technology.
Background technology
At present, in Switching Power Supply, generally use shunt or hall device to obtain the voltage signal of output current, but when output current was bigger, current sampling resistor had big power consumption, had reduced the efficient of transducer; And the Hall element volume is big, costs an arm and a leg, and increases the transducer cost.
The utility model content
The utility model is just in order to overcome above-mentioned technical matters, and design is a kind of on the basis of ortho-exciting electric source, utilizes the electric current synthetic technology to obtain the circuit of output current signal.
The technical scheme that its technical matters that solves the utility model adopts is: a kind of current detection circuit comprises voltage-controlled current source, current sampling circuit and transformer; It is characterized in that: 2 pin of transformer T1 connect the drain electrode of metal-oxide-semiconductor V4, and the source electrode of metal-oxide-semiconductor V4 links to each other with current sampling circuit; Current sampling circuit obtains on capacitor C 2 and the proportional voltage signal of outputting inductance L1 charging current by diode V1, resistance R 1; Output voltage V o and reference voltage V
REFObtain and the proportional control voltage of output voltage by divider resistance R7, R8, R9 respectively, output to the voltage-controlled current source control end, the output current of voltage-controlled current source carries out constant-current discharge to C2, voltage on C2 with the proportional slope variation of discharge slope of outputting inductance L1, simulation obtains and the proportional voltage signal of outputting inductance L1 discharge process; So just the current waveform on the synthetic in proportion outputting inductance L1 of the drain electrode of metal-oxide-semiconductor V2 again by the filtering of resistance R 2 capacitor C 1, obtains the output current signal I that needs
OUT
Its feature also is: voltage-controlled current source is made of resistance R 4, R5, R6, capacitor C 3, metal-oxide-semiconductor V2 and amplifier U1A, 1 pin of amplifier U1A links to each other with metal-oxide-semiconductor V2 grid by resistance R 4,2 pin of amplifier U1A link to each other with metal-oxide-semiconductor V2 source electrode by resistance R 6, and capacitor C 3 is connected in parallel on 1 pin and 2 pin of amplifier U1A; Metal-oxide-semiconductor V2 source electrode is by resistance R 5 ground connection, and metal-oxide-semiconductor V2 drain electrode links to each other with capacitor C 2.
Its feature also is: sample circuit is made up of current sensor T2, diode V3 and resistance R 10, current sensor T2 input end is serially connected in former limit or the secondary circuit, current sensor T2 output terminal and diode V3 and resistance R 10 polyphones, sampled signal is exported to the positive pole of diode V1 from the tie point of current sensor T2 and diode V3 positive pole.
Its feature also is: sample circuit also can be a resistance R 10, and sampled signal is exported to the positive pole of diode V1 from the tie point of the source electrode of diode V4 and resistance R 10.
Its feature also is: 3 pin of transformer T1 link to each other with diode V5 is anodal, diode V5 negative pole links to each other with diode V6 negative pole with the pin of outputting inductance L1, diode V6 positive pole links to each other with 4 pin of transformer T1, the bipod of capacitor C 5 links to each other with another pin of diode V6 negative pole and L1 respectively, and output voltage V o externally is provided.
Switching tube for the former limit of protection in the ortho-exciting electric source circuit generally all is connected to primary current detection means such as current sensor, but this device only can detect the electric current that flows through former limit switching tube, and the current signal that can't obtain to export.The former limit switching current signal that this utility model utilization monitors is by the current signal of an electric current synthetic line analog electrical output sense, thereby obtains output current signal.Principle of work is: in the time that metal-oxide-semiconductor V4 opens, and secondary diode V5 conducting, outputting inductance L1 charging; V4 is in the turn-off time, and outputting inductance L1 is by diode V6 discharge.The time internal inductance charging current that V4 opens is detected by current sensor T2, obtains on capacitor C 2 and the proportional voltage signal of outputting inductance charging current by diode V1, resistance R 1.No matter be that charging is gone back in the discharge process, the control voltage that is obtained of voltage-controlled current source is always proportional with output voltage.
V4 is in the turn-off time, and primary current blackout, secondary inductance are by diode V6 discharge, and its discharge slope k is expressed as: k=(Vo+Vd)/L
Vo is an output voltage in the formula, and Vd is a diode drop, the inductance value of L outputting inductance.
Constitute voltage-controlled current source by resistance R 4, R5, R6, capacitor C 3, metal-oxide-semiconductor V2 and amplifier U1A, output voltage V o and reference voltage V
REFObtain and the proportional control voltage of output voltage by divider resistance R7, R8 and R9 respectively, the output current of the above-mentioned current source of this Control of Voltage, this electric current carries out constant-current discharge to C2, voltage on the C2 with the proportional slope variation of discharge slope k of outputting inductance, simulation obtains the current waveform of this time period outputting inductance; The current waveform on the synthetic in proportion outputting inductance of the drain electrode of metal-oxide-semiconductor V2 so just.By the filtering of resistance R 2 capacitor C 1, obtain the output current signal that needs.
To capacitor C 2 chargings, voltage-controlled current source is to capacitor C 2 discharges by current sensor, and simulation obtains output current signal on capacitor C 2.The discharge current and the output voltage of this voltage-controlled current source are proportional.This technology can be widely used in except that being used for single-end ortho-exciting type circuit, also can being used for forward converters such as full-bridge or half-bridge in the control of display circuit, flow equalizing circuit of output current current foldback circuit, output current.
The beneficial effects of the utility model are to utilize electric current to synthesize to obtain output current signal, and circuit is simple, and cost is low.Avoid adopting shunt to obtain the big or high shortcoming of the use big cost of Hall element volume of output current signal power consumption.
Description of drawings
Fig. 1 is the current detection circuit schematic diagram of the utility model applied current synthetic technology.
Fig. 2 is the current detection circuit schematic diagram of applied current synthetic technology when adopting current sampling resistor.
Embodiment
Below in conjunction with drawings and Examples the utility model is further specified.
As illustrated in fig. 1 and 2, a kind of current detection circuit of the utility model comprises voltage-controlled current source, current sampling circuit and transformer.2 pin of transformer T1 connect the drain electrode of metal-oxide-semiconductor V4, and the source electrode of metal-oxide-semiconductor V4 links to each other with current sampling circuit; Current sampling circuit obtains on capacitor C 2 and the proportional voltage signal of outputting inductance L1 charging current by diode V1, resistance R 1; Output voltage V o and reference voltage V
REFObtain and the proportional control voltage of output voltage by divider resistance R7, R8, R9 respectively, output to the voltage-controlled current source control end, the output current of voltage-controlled current source carries out constant-current discharge to C2, voltage on C2 with the proportional slope variation of discharge slope of outputting inductance L1, simulation obtains and the proportional voltage signal of outputting inductance L1 discharge process; So just the current waveform on the synthetic in proportion outputting inductance L1 of the drain electrode of metal-oxide-semiconductor V2 again by the filtering of resistance R 2 capacitor C 1, obtains the output current signal I that needs
OUT
Voltage-controlled current source is made of resistance R 4, R5, R6, capacitor C 3, metal-oxide-semiconductor V2 and amplifier U1A, 1 pin of amplifier U1A links to each other with metal-oxide-semiconductor V2 grid by resistance R 4,2 pin of amplifier U1A link to each other with metal-oxide-semiconductor V2 source electrode by resistance R 6, and capacitor C 3 is connected in parallel on 1 pin and 2 pin of amplifier U1A; Metal-oxide-semiconductor V2 source electrode is by resistance R 5 ground connection, and metal-oxide-semiconductor V2 drain electrode links to each other with capacitor C 2.
Sample circuit can be made up of current sensor T2, diode V3 and resistance R 10, current sensor T2 input end is serially connected between the source electrode and ground of metal-oxide-semiconductor V4, current sensor T2 output terminal and diode V3 and resistance R 10 polyphones, sampled signal is exported to the positive pole of diode V1 from the tie point of current sensor T2 and diode V3 positive pole.
Sample circuit also can be to be made of separately resistance R 10, and sampled signal is exported to the positive pole of diode V1 from the tie point of the source electrode of diode V4 and resistance R 10.
The secondary output circuit is: 3 pin of transformer T1 link to each other with diode V5 is anodal, diode V5 negative pole links to each other with diode V6 negative pole with the pin of outputting inductance L1, diode V6 positive pole links to each other with 4 pin of transformer T1, the bipod of capacitor C 5 links to each other with another pin of diode V6 negative pole and L1 respectively, and output voltage V o externally is provided.
Claims (6)
1, a kind of current detection circuit comprises voltage-controlled current source, current sampling circuit and transformer; It is characterized in that: 2 pin of transformer T1 connect the drain electrode of metal-oxide-semiconductor V4, and the source electrode of metal-oxide-semiconductor V4 links to each other with current sampling circuit; Current sampling circuit obtains on capacitor C 2 and the proportional voltage signal of outputting inductance L1 charging current by diode V1, resistance R 1; Output voltage V o and reference voltage V
REFObtain and the proportional control voltage of output voltage by divider resistance R7, R8, R9 respectively, output to the voltage-controlled current source control end, the output current of voltage-controlled current source carries out constant-current discharge to C2, voltage on C2 with the proportional slope variation of discharge slope of outputting inductance L1, simulation obtains and the proportional voltage signal of outputting inductance L1 discharge process; So just the current waveform on the synthetic in proportion outputting inductance L1 of the drain electrode of metal-oxide-semiconductor V2 again by the filtering of resistance R 2 capacitor C 1, obtains the output current signal I that needs
OUT
2, current detection circuit according to claim 1, it is characterized in that: voltage-controlled current source is made of resistance R 4, R5, R6, capacitor C 3, metal-oxide-semiconductor V2 and amplifier U1A, 1 pin of amplifier U1A links to each other with metal-oxide-semiconductor V2 grid by resistance R 4,2 pin of amplifier U1A link to each other with metal-oxide-semiconductor V2 source electrode by resistance R 6, and capacitor C 3 is connected in parallel on 1 pin and 2 pin of amplifier U1A; Metal-oxide-semiconductor V2 source electrode is by resistance R 5 ground connection, and metal-oxide-semiconductor V2 drain electrode links to each other with capacitor C 2.
3, current detection circuit according to claim 1, it is characterized in that: sample circuit is made up of current sensor T2, diode V3 and resistance R 10, current sensor T2 input end is serially connected in the circuit of former limit, current sensor T2 output terminal and diode V3 and resistance R 10 polyphones, sampled signal is exported to the positive pole of diode V1 from the tie point of current sensor T2 and diode V3 positive pole.
4, current detection circuit according to claim 1, it is characterized in that: sample circuit is made up of current sensor T2, diode V3 and resistance R 10, current sensor T2 input end is serially connected in the secondary circuit, current sensor T2 output terminal and diode V3 and resistance R 10 polyphones, sampled signal is exported to the positive pole of diode V1 from the tie point of current sensor T2 and diode V3 positive pole.
5, current detection circuit according to claim 1 is characterized in that: sample circuit is a resistance R 10, and sampled signal is exported to the positive pole of diode V1 from the tie point of the positive pole of diode V3 and resistance R 10.
6, current detection circuit according to claim 1, it is characterized in that: 3 pin of transformer T1 link to each other with diode V5 is anodal, diode V5 negative pole links to each other with diode V6 negative pole with the pin of outputting inductance L1, diode V6 positive pole links to each other with 4 pin of transformer T1, the bipod of capacitor C 5 links to each other with another pin of diode V6 negative pole and L1 respectively, and output voltage V o externally is provided.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620000753 CN2881654Y (en) | 2006-01-13 | 2006-01-13 | Current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620000753 CN2881654Y (en) | 2006-01-13 | 2006-01-13 | Current detection circuit |
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| CN2881654Y true CN2881654Y (en) | 2007-03-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200620000753 Expired - Fee Related CN2881654Y (en) | 2006-01-13 | 2006-01-13 | Current detection circuit |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008113239A1 (en) * | 2007-03-22 | 2008-09-25 | Huawei Technologies Co., Ltd. | A current testing circuit and device |
| CN101655516B (en) * | 2008-08-20 | 2012-08-22 | 力博特公司 | Main-circuit input current detection device |
| CN103675404A (en) * | 2012-09-05 | 2014-03-26 | 快捷半导体(苏州)有限公司 | Method, device, and system for sensing and regulating inductor current in inductor |
| CN103931205A (en) * | 2011-11-15 | 2014-07-16 | 株式会社爱霓威亚 | Fault detection method and substation terminal used for said method |
| CN106291045A (en) * | 2015-05-22 | 2017-01-04 | 登腾电子股份有限公司 | Current sensing module, power conversion device and electronic device applying same |
| CN110456232A (en) * | 2019-09-02 | 2019-11-15 | 北京智芯微电子科技有限公司 | The low-power current detection circuit of the independent powering mode of fault detector battery |
| CN112711285A (en) * | 2020-12-22 | 2021-04-27 | 深圳市艾尔曼医疗电子仪器有限公司 | Programmable high-voltage reference unit circuit and high-voltage reference source |
-
2006
- 2006-01-13 CN CN 200620000753 patent/CN2881654Y/en not_active Expired - Fee Related
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008113239A1 (en) * | 2007-03-22 | 2008-09-25 | Huawei Technologies Co., Ltd. | A current testing circuit and device |
| US7768290B2 (en) | 2007-03-22 | 2010-08-03 | Huawei Technologies Co., Ltd. | Circuit and apparatus for detecting electric current |
| CN101655516B (en) * | 2008-08-20 | 2012-08-22 | 力博特公司 | Main-circuit input current detection device |
| CN103931205A (en) * | 2011-11-15 | 2014-07-16 | 株式会社爱霓威亚 | Fault detection method and substation terminal used for said method |
| CN103931205B (en) * | 2011-11-15 | 2017-12-29 | 株式会社爱霓威亚 | Fault detection method and the secondary terminal station for being used in this method |
| CN103675404A (en) * | 2012-09-05 | 2014-03-26 | 快捷半导体(苏州)有限公司 | Method, device, and system for sensing and regulating inductor current in inductor |
| CN106291045A (en) * | 2015-05-22 | 2017-01-04 | 登腾电子股份有限公司 | Current sensing module, power conversion device and electronic device applying same |
| CN106291045B (en) * | 2015-05-22 | 2019-02-19 | 登腾电子股份有限公司 | Current sensing module, power conversion device and electronic device applying same |
| CN110456232A (en) * | 2019-09-02 | 2019-11-15 | 北京智芯微电子科技有限公司 | The low-power current detection circuit of the independent powering mode of fault detector battery |
| CN110456232B (en) * | 2019-09-02 | 2021-07-27 | 北京智芯微电子科技有限公司 | Low-power-consumption current detection circuit of fault indicator battery independent power supply mode |
| CN112711285A (en) * | 2020-12-22 | 2021-04-27 | 深圳市艾尔曼医疗电子仪器有限公司 | Programmable high-voltage reference unit circuit and high-voltage reference source |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| ASS | Succession or assignment of patent right |
Owner name: BEIJING DI SAICH TECHNOLOGY CO., LTD. Free format text: FORMER OWNER: BEIJING DONGLIYUAN TECHNOLOGY CO.,LTD. Effective date: 20080523 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20080523 Address after: Room 8, Spark Road, No. 411, Fengtai District Science City, Beijing, China: 100070 Patentee after: Beijing Design Technology Co., Ltd. Address before: No. 8, Spark Road, Fengtai District Science City, Beijing, China: 100070 Patentee before: Beijing Power Producer Science and Technology Co., Ltd. |
|
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20070321 Termination date: 20150113 |
|
| EXPY | Termination of patent right or utility model |