CN203261230U - THD correction circuit of PFC - Google Patents
THD correction circuit of PFC Download PDFInfo
- Publication number
- CN203261230U CN203261230U CN 201320270928 CN201320270928U CN203261230U CN 203261230 U CN203261230 U CN 203261230U CN 201320270928 CN201320270928 CN 201320270928 CN 201320270928 U CN201320270928 U CN 201320270928U CN 203261230 U CN203261230 U CN 203261230U
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- pfc
- thd
- correction circuit
- triode
- circuit
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Abstract
The utility model discloses a THD correction circuit of a PFC. The PFC comprises a PFC control chip and a MOS transistor. The THD correction circuit of the PFC comprises a first resistor, a first diode, a first triode and a detection control circuit; a positive electrode of the first diode is connected with a zero crossing detection port of the PFC control chip and a negative electrode is connected with a collector electrode of the first triode via the first resistor; an emission electrode of the first triode is connected to the ground and a base electrode is connected to the detection control circuit; and the detection control circuit is connected with the MOS transistor. The THD correction circuit of the PFC controls the operating frequency of the MOS transistor by detecting the wave forms of current passing through the MOS transistor, so an objective that the THD is effectively reduced is achieved. The THD correction circuit of the PFC is available for low-power products which particularly require that the THD of a harmonic wave is less than 10%, and solves a problem of greater THD caused by wide-range input voltage.
Description
Technical field
The utility model relates to the THD circuit, particularly the THD correction circuit of a kind of PFC.
Background technology
At present, there is the power factor controlling PFC(Power Factor Correction of oneself in many companies) chip, but most chip when the input of wide voltage or the THD (Total Harmonic Distortion total harmonic distortion) of load variations scope when larger (particularly bearing power hour) all can be larger, may reach 20%.But now also more and more higher to the THD requirement of small-power electronic product, there is larger market demands THD to satisfy＜10%.
Traditional pfc circuit for the larger power supply of power (more than the 25W) to accomplish total harmonic wave＜10% with interior be to be relatively easy to, but at 25W with interior will accomplishing＜10%, adopt traditional harmonic management mode to be difficult to accomplish, the development trend of present global product is energy-conserving and environment-protective, along with the development of society and the minimizing of earth energy, even now low power product also require THD can accomplish＜10%, can greatly improve like this utilance of national grid, be earth energy savings.
In view of this, prior art is still waiting to improve and improve.
The utility model content
In view of above-mentioned the deficiencies in the prior art part, the purpose of this utility model is to provide the THD correction circuit of a kind of PFC, be difficult to total harmonic wave is accomplished for lower-powered product to solve existing pfc circuit＜10% with interior problem.
In order to achieve the above object, the utility model has been taked following technical scheme:
The THD correction circuit of a kind of PFC comprises a PFC control chip and a metal-oxide-semiconductor among the described PFC, wherein, the THD correction circuit of described PFC comprises:
The first resistance, the first diode, the first triode and detect control circuit;
Wherein, the positive pole of described the first diode connects the zero passage detection end of PFC control chip, and negative pole connects the collector electrode of the first triode by the first resistance; The grounded emitter of described the first triode, base stage are connected to the detection control circuit, and described detection control circuit connects metal-oxide-semiconductor.
The THD correction circuit of described PFC, wherein, described the first triode is the NPN triode.
The THD correction circuit of described PFC, wherein, described PFC control chip is that the model that ST company produces is the PFC control chip of L6562.
The THD correction circuit of described PFC, wherein, described metal-oxide-semiconductor is the N metal-oxide-semiconductor.
Beneficial effect:
Compared to prior art, the THD correction circuit of a kind of PFC that the utility model provides flows through the electric current of metal-oxide-semiconductor by detection, controls the operating frequency of metal-oxide-semiconductor, thereby reaches the purpose that effectively reduces THD.It is applicable to the occasion that small-power has specific (special) requirements harmonic wave THD＜10%, and has solved wide-range input voltage and cause the problem that THD is larger.
Description of drawings
Fig. 1 is the circuit diagram of the pfc circuit of prior art.
The schematic diagram of the pfc circuit of the THD correction circuit that is provided with the utility model and provides is provided Fig. 2.
Embodiment
The utility model provides the THD correction circuit of a kind of PFC, and being used for small-power has the occasion of specific (special) requirements harmonic wave THD＜10%, and has solved wide-range input voltage and cause the problem that THD is larger.
For making the purpose of this utility model, technical scheme and effect clearer, clear and definite, referring to the accompanying drawing embodiment that develops simultaneously the utility model is further described.Should be appreciated that specific embodiment described herein only in order to explaining the utility model, and be not used in restriction the utility model.
Understand for the aspect, please consult first Fig. 1, it is the circuit diagram of the pfc circuit of prior art.Be convenient and understand that described pfc circuit illustrates take the L6562 of ST company commonly used as the PFC control chip.As shown in the figure, represent L6562 with IC1 among the figure, N represents zero line, and L represents live wire.Its circuit theory diagrams can referring to the IC data of L6562, just no longer be done too much and give unnecessary details here.
Please continue to consult Fig. 2, schematic diagram of the pfc circuit of the THD correction circuit that is provided with the utility model and provides is provided for it.As shown in the figure, in order to make harmonic wave THD＜10%, solved wide-range input voltage and caused the problem that THD is larger.The utility model provides the THD correction circuit of a kind of PFC, and it comprises: the first resistance R 1, the first diode D1, the first triode Q1 and one detect control circuit; In addition, comprise a PFC control chip IC1 and a metal-oxide-semiconductor V1 among the described PFC.
Wherein, the positive pole of described the first diode D1 connects the zero passage detection end 5 of PFC control chip IC1, and negative pole connects the collector electrode of the first triode Q1 by the first resistance R 1; The grounded emitter of described the first triode Q1, base stage are connected to the detection control circuit, and described detection control circuit connects metal-oxide-semiconductor V1.
Specifically, detect control circuit for detection of the current waveform of metal-oxide-semiconductor V1.Flow through the current waveform of metal-oxide-semiconductor V1 by detection, the pwm signal of detection control circuit output fixed frequency and duty ratio is controlled the conducting of the first triode Q1 and is closed, thereby the conducting by the first triode Q1 and close to affect the zero passage detection end 5 of control chip IC1, make control chip IC1 send the operating frequency that control signal reduces metal-oxide-semiconductor V1, thereby reach the purpose that effectively reduces THD.
Find that through research the THD correction circuit of PFC of the present utility model is applicable to the occasion that small-power has specific (special) requirements harmonic wave THD＜10%, and solved wide-range input voltage and cause the problem that THD is larger.
Further, in the THD of described PFC correction circuit, described the first triode Q1 is the NPN triode.In addition, described metal-oxide-semiconductor can be the N metal-oxide-semiconductor.
In sum, the THD correction circuit of a kind of PFC that the utility model provides, comprise a PFC control chip and a metal-oxide-semiconductor among the described PFC, wherein, the THD correction circuit of described PFC comprises: the first resistance, the first diode, the first triode and detect control circuit; The positive pole of described the first diode connects the zero passage detection end of PFC control chip, and negative pole connects the collector electrode of the first triode by the first resistance; The grounded emitter of described the first triode, base stage are connected to the detection control circuit, and described detection control circuit connects metal-oxide-semiconductor.Flow through the current waveform of metal-oxide-semiconductor by detection, control the operating frequency of metal-oxide-semiconductor, thereby reach the purpose that effectively reduces THD.It is applicable to the occasion that small-power has specific (special) requirements harmonic wave THD＜10%, and has solved wide-range input voltage and cause the problem that THD is larger.
Be understandable that; for those of ordinary skills; can be equal to replacement or change according to the technical solution of the utility model and utility model design thereof, and all these changes or replacement all should belong to the protection range of the appended claim of the utility model.
Claims (4)
1. the THD correction circuit of a PFC comprises a PFC control chip and a metal-oxide-semiconductor among the described PFC, it is characterized in that, the THD correction circuit of described PFC comprises:
The first resistance, the first diode, the first triode and detect control circuit;
Wherein, the positive pole of described the first diode connects the zero passage detection end of PFC control chip, and negative pole connects the collector electrode of the first triode by the first resistance; The grounded emitter of described the first triode, base stage are connected to the detection control circuit, and described detection control circuit connects metal-oxide-semiconductor.
2. the THD correction circuit of PFC according to claim 1 is characterized in that, described the first triode is the NPN triode.
3. the THD correction circuit of PFC according to claim 1 is characterized in that, the model of described PFC control chip is the PFC control chip of L6562.
4. the THD correction circuit of PFC according to claim 1 is characterized in that, described metal-oxide-semiconductor is the NMOS pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320270928 CN203261230U (en) | 2013-05-17 | 2013-05-17 | THD correction circuit of PFC |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320270928 CN203261230U (en) | 2013-05-17 | 2013-05-17 | THD correction circuit of PFC |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203261230U true CN203261230U (en) | 2013-10-30 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320270928 Expired - Fee Related CN203261230U (en) | 2013-05-17 | 2013-05-17 | THD correction circuit of PFC |
Country Status (1)
| Country | Link |
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| CN (1) | CN203261230U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113394963A (en) * | 2020-03-11 | 2021-09-14 | 上海海立（集团）股份有限公司 | PFC circuit detection method and device and readable storage medium |
-
2013
- 2013-05-17 CN CN 201320270928 patent/CN203261230U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113394963A (en) * | 2020-03-11 | 2021-09-14 | 上海海立（集团）股份有限公司 | PFC circuit detection method and device and readable storage medium |
| CN113394963B (en) * | 2020-03-11 | 2023-11-10 | 上海海立（集团）股份有限公司 | PFC circuit detection method and device and readable storage medium |
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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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131030 Termination date: 20210517 |