CN107404217B - Switching power supply control circuit and method and switching power supply - Google Patents
Switching power supply control circuit and method and switching power supply Download PDFInfo
- Publication number
- CN107404217B CN107404217B CN201710712428.2A CN201710712428A CN107404217B CN 107404217 B CN107404217 B CN 107404217B CN 201710712428 A CN201710712428 A CN 201710712428A CN 107404217 B CN107404217 B CN 107404217B
- Authority
- CN
- China
- Prior art keywords
- switching tube
- power supply
- main switching
- control circuit
- main
- 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
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Abstract
The invention discloses a switching power supply control circuit and method and a switching power supply. A switching power supply control circuit comprising: the main switching tube control circuit receives the first signal and the second signal and outputs a main switching tube control signal representing the on and off of the main switching tube; the auxiliary switching tube control circuit receives signals representing the conduction time of the main switching tube, when the signals representing the conduction time of the main switching tube reach a conduction threshold value, the auxiliary switching tube is turned off, and when the signals representing the conduction time of the main switching tube are smaller than the conduction threshold value, auxiliary switching tube control signals representing the conduction and the turn-off of the auxiliary switching tube are generated according to the main switching tube control signals. The invention can further increase the maximum duty cycle, thereby further increasing the maximum value of the output voltage.
Description
Technical Field
The present invention relates to the field of power electronics, and more particularly, to a switching power supply control circuit and method, and a switching power supply.
Background
The circuit structure types of the prior art switching power supply include a Buck circuit (Buck circuit), a Boost circuit (Boost circuit), a Forward circuit (Forward circuit), a Flyback circuit (Flyback circuit), and the like, and can convert an input voltage into a required output voltage to drive a load. In practice, these circuits generally comprise a main switching tube and an auxiliary switching tube. In the prior art, the main switching tube and the auxiliary switching tube are driven to be turned on and off in a synchronous control mode, so that the purpose of voltage regulation is achieved. The synchronous control means that the conduction and the switching of the main switching tube and the auxiliary switching tube are opposite and synchronous. As shown in fig. 1, the switching signal is triggered to act on the falling edge of the clock signal, the main switching tube is turned on, the auxiliary switching tube is turned off, and the output signal of the error amplifier or the comparator controls the main switching tube to be turned off and the auxiliary switching tube to be turned on after the time Ton. In this process, the on and off of the main switching tube and the auxiliary switching tube are opposite, and the changes of on and off are synchronized.
In the prior art, i.e. synchronous control, the above process is continuously increased along with Ton, the on time of the main switching tube is gradually increased until the rising edge of the pulse signal arrives earlier than the output signal of the error amplifier or comparator, at this time, the rising edge of the pulse signal directly turns off the main switching tube, the auxiliary switching tube is turned on, and Ton reaches the maximum value, i.e. Ton (max). Since the auxiliary switching tube has a minimum on-time, the main switching tube has a corresponding minimum off-time due to the synchronous control, which the main switching tube must be turned off, so that the maximum on-time Ton (max) of the main switching tube is limited. As shown in fig. 2, the pulse rising edge controls the turn-off of the main switching tube, and the minimum on time Bon (min) of the auxiliary switching tube controls the turn-on of the main switching tube, at this time, the main switching tube has the maximum on time Ton (max), the duty ratio reaches the maximum, and the output voltage reaches the maximum. In synchronous control, the maximum on time of the main switching tube is limited, at the moment, the on time of the main switching tube cannot be continuously increased, and the duty ratio cannot be continuously increased, so that the range of output voltage is limited to a certain extent.
Disclosure of Invention
In view of this, the present invention provides a switching power supply control circuit and method, and a switching power supply, which can further increase the on time of the main switching tube, so that the duty ratio can be further increased, thereby further increasing the maximum value of the output voltage.
The invention provides a switching power supply control circuit, which comprises:
the main switching tube control circuit receives the first signal and the second signal and outputs a main switching tube control signal representing the on and off of the main switching tube;
the auxiliary switching tube control circuit receives signals representing the conduction time of the main switching tube, when the signals representing the conduction time of the main switching tube reach a conduction threshold value, the auxiliary switching tube is turned off, and when the signals representing the conduction time of the main switching tube are smaller than the conduction threshold value, auxiliary switching tube control signals representing the conduction and the turn-off of the auxiliary switching tube are generated according to the main switching tube control signals.
Optionally, the auxiliary switching tube control circuit includes a comparison circuit, the comparison circuit receives a signal representing the on time of the main switching tube and a signal representing the on threshold value respectively, and when the signal representing the on time of the main switching tube reaches the on threshold value, the auxiliary switching tube is in an off state until the signal representing the on time of the main switching tube is smaller than the signal representing the on threshold value.
Optionally, the switching power supply control circuit further includes a main switching tube time detection circuit, receives the main switching tube control signal indicating the on and off of the main switching tube, and outputs the signal indicating the on time of the main switching tube.
Optionally, the conduction threshold value refers to the set maximum conduction time of the main switching tube in synchronous control.
Optionally, the auxiliary switching tube control circuit further includes an inverter and a nor gate, the comparison circuit receives a signal representing the on time of the main switching tube and a signal representing the on threshold value, the output end of the comparison circuit is connected to the first input end of the nor gate, the inverter receives the auxiliary switching tube control signal representing the on and off of the auxiliary switching tube generated according to the main switching tube control signal, the output end of the inverter is connected to the second input end of the nor gate, and the nor gate outputs the auxiliary switching tube control signal representing the off or on and off of the auxiliary switching tube.
Optionally, the first signal is a pulse signal, and the second signal is an output signal of an error amplifier in the switching power supply.
A switching power supply control method based on the switching power supply control circuit comprises the following steps:
comparing a signal indicative of the on-time of the main switching tube with an on-threshold,
when the signal representing the on time of the main switching tube is larger than or equal to an on threshold value, the auxiliary switching tube is turned off;
and when the signal representing the on time of the main switching tube is smaller than the on threshold value, generating an auxiliary switching tube control signal representing the on and off of the auxiliary switching tube according to the main switching tube control signal.
A switching power supply, comprising: the control end of the auxiliary switching tube is connected with the output end of the auxiliary switching tube control circuit of the switching power supply control circuit.
Compared with the prior art, the technical scheme of the invention has the following advantages: the invention compares the signal representing the on time of the main switching tube with the on threshold, and when the signal representing the on time of the switching tube is larger than the on threshold, the auxiliary switching tube is always turned off, and the on time of the main switching tube is increased by reducing the on time of the auxiliary switching tube, so that the duty ratio of the prior art is further increased, and the maximum value of the output voltage is further improved, therefore, the invention can increase the voltage regulating range of the voltage regulating circuit.
Drawings
FIG. 1 is a schematic diagram of a prior art synchronous control of the on and off of a primary and secondary switching tube;
FIG. 2 is a schematic diagram of the prior art for synchronously controlling the on and off of a main and auxiliary switching tube when the on time of the main switch is maximum;
FIG. 3 is a schematic diagram of an embodiment of a switching power supply control circuit of the present invention;
FIG. 4 is a schematic diagram of an embodiment of an auxiliary switching tube control circuit of the present invention;
FIG. 5 is a schematic diagram of the present invention for controlling the on and off of the main and auxiliary switching tubes when the on time of the main switching tube is greater than or equal to the on threshold;
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to these embodiments only. The invention is intended to cover any alternatives, modifications, equivalents, and variations that fall within the spirit and scope of the invention.
In the following description of preferred embodiments of the invention, specific details are set forth in order to provide a thorough understanding of the invention, and the invention will be fully understood to those skilled in the art without such details.
The invention is more particularly described by way of example in the following paragraphs with reference to the drawings. It should be noted that the drawings are in a simplified form and are not to scale precisely, but rather are merely intended to facilitate and clearly illustrate the embodiments of the present invention.
Fig. 3 illustrates a circuit configuration of an embodiment of the switching power supply control circuit of the present invention. The switching power supply control circuit comprises a main switching tube control circuit, a main switching tube conduction time detection circuit and an auxiliary switching tube control circuit.
The main switching tube control circuit receives the first signal and the second signal, outputs a T signal representing the on and off of the main switching tube, and further controls the on and off of the main switching tube; the main switch tube on-time detection circuit receives the control signals representing the on and off of the main switch tube, namely a T signal, and outputs a signal representing the main switch on-time Ton; one input end of the auxiliary switching tube control circuit receives a signal representing the on time Ton of the main switch, the other input end of the auxiliary switching tube control circuit generates an auxiliary switching tube control signal representing the on and off of the auxiliary switching tube according to the main switching tube control signal, the auxiliary switching tube control signal is marked as a B signal, and the B signal and the T signal are synchronous and opposite. The switching power supply is a Buck circuit, and Buck comprises: a first switching tube M1, a second switching tube M2, an inductor L and a capacitor C. The drain electrode of the first switching tube M1 is connected with the input voltage, the source electrode of the first switching tube M1 is connected with the drain electrode of the second switching tube M2, and the source electrode of the second switching tube M2 is grounded. One end of the inductor L1 is connected with the common end of the first switching tube M1 and the second switching tube M2, and the other end of the inductor L1 is used as a high potential end of the output end. One end of the capacitor C is connected with the high potential end of the output end, and the other end of the capacitor C is grounded. The output end of the main switching tube driving circuit is connected with the grid electrode of the main switching tube M1, and the auxiliary switching tube driving circuit is connected to the grid electrode of the auxiliary switching tube M2.
When the signal representing the on time Ton of the main switching tube reaches an on threshold, the auxiliary switching tube is turned off, and when the signal representing the on time Ton of the main switching tube is smaller than the on threshold, an auxiliary switching tube control signal representing the on and off of the auxiliary switching tube, namely a B signal, is generated according to the main switching tube control signal.
In this embodiment, the first signal is a pulse signal, and the second signal is an output signal of an error amplifier in the switching power supply, but the signals related to the first signal and the second signal and having the same function are all within the protection scope of the present invention. The switching power supply error amplifier is not shown in the figures, since it is not an important part of the present invention.
As shown in fig. 4, an embodiment of an auxiliary switching tube control current is illustrated, the auxiliary switching tube control circuit includes a comparison circuit U01, an inverter and a nor gate U02, a first input terminal of the comparison circuit U01 receives a turn-on time Ton of the main switching tube, a second input terminal of the comparison circuit U01 receives a turn-on threshold value, an output terminal of the comparison circuit is connected to a first input terminal of the nor gate U02, the inverter receives an auxiliary switching tube control signal, i.e., a B signal, representing turning-on and turning-off of the auxiliary switching tube according to the main switching tube control signal, an output of the inverter is connected to a second input terminal of the nor gate U02, and the nor gate U02 outputs the auxiliary switching tube control signal representing turning-off or turning-on and turning-off of the auxiliary switching tube.
The conduction threshold may be set to a maximum conduction time of the main switching tube, or may be a constant that leaves a certain threshold to the maximum conduction time of the main switching tube, or may be another value that may represent a conduction time limit. The on threshold of the present embodiment is set to the maximum on time Tmax of the main switching tube, but other relevant on threshold settings are also within the scope of the present invention.
In fig. 4, the on threshold Tmax signal and the on time Ton signal of the main switching tube are compared, if Ton > Tmax, the comparison circuit U01 outputs a logic high level 1, and after passing through the nor gate U02, the comparison circuit directly outputs a logic low level 0, so that the auxiliary switching tube is turned off; if Ton < Tmax, the comparison circuit U01 outputs a logic low level 0, and the nor gate U02 follows the auxiliary switch control signal, i.e., the B signal, so as to control the on and off of the auxiliary switch tube. That is, when Ton > Tmax, the auxiliary switching tube is always turned off, as shown in fig. 5. Until Ton < Tmax, the on and off of the auxiliary switching tube is synchronous and opposite to the main switching tube, namely the same as the synchronous control process, as shown in fig. 1 and 2.
In the prior art, namely synchronous control, the on signal Ton of the main switching tube is controlled by the output signal of the error amplifier or the comparator, namely the output signal of the error amplifier or the comparator controls the turn-off of the main switching tube; with the continuous increase of Ton, the on time of the main switching tube gradually increases until the rising edge of the pulse signal arrives earlier than the output signal of the error amplifier or the comparator, at this time, the rising edge of the pulse signal directly turns off the main switching tube, the auxiliary switching tube turns on, and Ton reaches the maximum value, i.e., tmax. In synchronous control, the auxiliary switching tube has a minimum on time, namely the main switching tube has a minimum off time, and the main switching tube can be turned on after the minimum off time is needed to be turned off, so that the maximum on time of the main switching tube is limited. The invention effectively avoids the situation, and can ensure that the conduction time of the main switching tube can still be continuously increased after reaching the maximum conduction time Tmax. When the detected on time Ton of the main switching tube is greater than or equal to the on threshold Tmax, the auxiliary switching tube control circuit controls the auxiliary switching tube to be turned off all the time, at the moment, the on and off of the main switching tube are respectively controlled by the falling edge and the rising edge of the pulse, and the high level of the pulse is generally far smaller than the off time of the auxiliary switching tube, so that after the on time Ton of the main switching tube reaches the on threshold Tmax, the on time Ton of the main switching tube can be continuously increased, and the duty ratio is further increased.
In addition, the example given here is the case of a Buck circuit, but the present invention is applicable to any circuit including a main switching transistor and an auxiliary switching transistor, and in which the control manner of the main switching transistor and the auxiliary switching transistor is synchronous control.
Although the embodiments have been described and illustrated separately above, and with respect to a partially common technique, it will be apparent to those skilled in the art that alternate and integration may be made between embodiments, with reference to one embodiment not explicitly described, and reference may be made to another embodiment described.
The above-described embodiments do not limit the scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the above embodiments should be included in the scope of the present invention.
Claims (8)
1. A switching power supply control circuit, comprising:
the main switching tube control circuit receives the first signal and the second signal and outputs a main switching tube control signal representing the on and off of the main switching tube;
the auxiliary switching tube control circuit receives signals representing the conduction time of the main switching tube, when the signals representing the conduction time of the main switching tube reach a conduction threshold value, the auxiliary switching tube is turned off, and when the signals representing the conduction time of the main switching tube are smaller than the conduction threshold value, auxiliary switching tube control signals representing the conduction and the turn-off of the auxiliary switching tube are generated according to the main switching tube control signals.
2. The switching power supply control circuit according to claim 1, wherein: the auxiliary switching tube control circuit comprises a comparison circuit, wherein the comparison circuit receives signals representing the conduction time of the main switching tube and signals representing the conduction threshold value respectively, and when the signals representing the conduction time of the main switching tube reach the conduction threshold value, the auxiliary switching tube is in an off state until the signals representing the conduction time of the main switching tube are smaller than the signals representing the conduction threshold value.
3. The switching power supply control circuit according to claim 1 or 2, wherein: the switching power supply control circuit also comprises a main switching tube time detection circuit, receives a main switching tube control signal representing the on and off of the main switching tube and outputs a signal representing the on time of the main switching tube.
4. The switching power supply control circuit according to claim 1 or 2, wherein: the conduction threshold value refers to the set maximum conduction time of the main switching tube in synchronous control.
5. The switching power supply control circuit according to claim 2, wherein: the auxiliary switching tube control circuit further comprises an inverter and a NOR gate, the comparison circuit receives signals representing the on time of the main switching tube and signals representing the on threshold value respectively, the output end of the comparison circuit is connected to the first input end of the NOR gate, the inverter receives auxiliary switching tube control signals representing the on and off of the auxiliary switching tube generated according to the main switching tube control signals, the output end of the inverter is connected to the second input end of the NOR gate, and the NOR gate outputs auxiliary switching tube control signals representing the on and off of the auxiliary switching tube.
6. The switching power supply control circuit according to claim 1, wherein: the first signal is a pulse signal, and the second signal is an output signal of an error amplifier in the switching power supply.
7. A switching power supply control method, based on the switching power supply control circuit of any one of claims 1 to 6, comprising:
comparing a signal indicative of the on-time of the main switching tube with an on-threshold,
when the signal representing the on time of the main switching tube is larger than or equal to an on threshold value, the auxiliary switching tube is turned off;
and when the signal representing the on time of the main switching tube is smaller than the on threshold value, generating an auxiliary switching tube control signal representing the on and off of the auxiliary switching tube according to the main switching tube control signal.
8. A switching power supply, comprising: the switching power supply comprises a main switching tube, an auxiliary switching tube and any one of the switching power supply control circuits in claims 1-6, wherein the control end of the main switching tube is connected with the output end of the main switching tube control circuit of the switching power supply control circuit, and the control end of the auxiliary switching tube is connected with the output end of the auxiliary switching tube control circuit of the switching power supply control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710712428.2A CN107404217B (en) | 2017-08-18 | 2017-08-18 | Switching power supply control circuit and method and switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710712428.2A CN107404217B (en) | 2017-08-18 | 2017-08-18 | Switching power supply control circuit and method and switching power supply |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107404217A CN107404217A (en) | 2017-11-28 |
| CN107404217B true CN107404217B (en) | 2023-06-23 |
Family
ID=60396483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710712428.2A Active CN107404217B (en) | 2017-08-18 | 2017-08-18 | Switching power supply control circuit and method and switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107404217B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101227147A (en) * | 2008-02-19 | 2008-07-23 | 北京中星微电子有限公司 | Direct current switch power supply control circuit |
| JP2009148157A (en) * | 2007-12-12 | 2009-07-02 | Micrel Inc | Voltage regulator for utilizing fixed on time with increased maximum duty cycle |
| JP2016032319A (en) * | 2014-07-28 | 2016-03-07 | ローム株式会社 | Switching power supply device |
| CN105790581A (en) * | 2016-05-19 | 2016-07-20 | 杰华特微电子（杭州）有限公司 | Switching control circuit, switching circuit and constant switching-on time control method |
| CN207459981U (en) * | 2017-08-18 | 2018-06-05 | 杰华特微电子（杭州）有限公司 | Switching power source control circuit and Switching Power Supply |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104393743B (en) * | 2014-11-21 | 2017-04-12 | 矽力杰半导体技术(杭州)有限公司 | Control circuit, control method and switching mode convertor |
-
2017
- 2017-08-18 CN CN201710712428.2A patent/CN107404217B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009148157A (en) * | 2007-12-12 | 2009-07-02 | Micrel Inc | Voltage regulator for utilizing fixed on time with increased maximum duty cycle |
| CN101227147A (en) * | 2008-02-19 | 2008-07-23 | 北京中星微电子有限公司 | Direct current switch power supply control circuit |
| JP2016032319A (en) * | 2014-07-28 | 2016-03-07 | ローム株式会社 | Switching power supply device |
| CN105790581A (en) * | 2016-05-19 | 2016-07-20 | 杰华特微电子（杭州）有限公司 | Switching control circuit, switching circuit and constant switching-on time control method |
| CN207459981U (en) * | 2017-08-18 | 2018-06-05 | 杰华特微电子（杭州）有限公司 | Switching power source control circuit and Switching Power Supply |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107404217A (en) | 2017-11-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10608543B2 (en) | Resonant converter and driving method thereof | |
| US9831777B2 (en) | Switch control circuit and converter including the same | |
| KR101677728B1 (en) | Power factor correction circuit and driving method thereof | |
| US9634555B2 (en) | Method for operating a non-isolated switching converter having synchronous rectification capability suitable for power factor correction applications | |
| US8649129B2 (en) | Method and apparatus of providing over-temperature protection for power converters | |
| US10199946B2 (en) | Systems and methods for adjusting peak frequencies with duty cycles | |
| US20140198539A1 (en) | Systems and methods for zero voltage switching in power conversion systems | |
| JP5136892B2 (en) | Voltage control device, power supply device, electron tube and high-frequency circuit system | |
| KR101812703B1 (en) | Over voltage repetition prevention circuit, method thereof, and power factor compensation circuit using the same | |
| JP2021013259A (en) | Gate drive device and power conversion device | |
| US10104728B2 (en) | LED driving circuit, LED device comprising the same, and driving method of LED | |
| CN111786560A (en) | Synchronous rectification control method, control circuit and switching power supply | |
| JP4548484B2 (en) | Synchronous rectification forward converter | |
| CN111786563A (en) | Synchronous rectification control circuit and switching power supply | |
| KR20130057320A (en) | Switch controller, switch control method, and power supply device comprising the switch controller | |
| US10418910B2 (en) | Isolated switch-mode power supply and control circuit and control method for isolated switch-mode power supply | |
| US7848119B2 (en) | Direct current to direct current converter | |
| JP2007202313A (en) | Switching control circuit | |
| CN107404217B (en) | Switching power supply control circuit and method and switching power supply | |
| US11883912B2 (en) | Welding power supply device | |
| US9673622B2 (en) | Power supplying system, linear controlling module thereof, and controlling method of switching component | |
| CN108063554B (en) | Control circuit, control method and switching circuit of switching power supply | |
| CN213602561U (en) | Control circuit of switch circuit and switch circuit | |
| CN110707917B (en) | Bridge converter driving dead zone self-adjusting method and device | |
| US20180248471A1 (en) | Switching power supply, primary control chip and loop compensation device thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: Room 901-23, 9 / F, west 4 building, Xigang development center, 298 Zhenhua Road, Sandun Town, Xihu District, Hangzhou City, Zhejiang Province, 310030 Applicant after: Jiehuate Microelectronics Co.,Ltd. Address before: Room 424, building 1, 1500 Wenyi West Road, Cangqian street, Yuhang District, Hangzhou City, Zhejiang Province Applicant before: JOULWATT TECHNOLOGY Inc.,Ltd. |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |