CN113655363A - On-line testing circuit for conduction voltage drop of main switching tube of switching power supply - Google Patents
On-line testing circuit for conduction voltage drop of main switching tube of switching power supply Download PDFInfo
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- CN113655363A CN113655363A CN202111067353.XA CN202111067353A CN113655363A CN 113655363 A CN113655363 A CN 113655363A CN 202111067353 A CN202111067353 A CN 202111067353A CN 113655363 A CN113655363 A CN 113655363A
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- Prior art keywords
- power supply
- pole
- diode
- switching tube
- supply circuit
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- 238000012360 testing method Methods 0.000 title claims abstract description 32
- 239000003990 capacitor Substances 0.000 claims description 48
- 238000004804 winding Methods 0.000 claims description 19
- 239000000523 sample Substances 0.000 claims description 4
- 238000010998 test method Methods 0.000 abstract description 3
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/26—Testing of individual semiconductor devices
- G01R31/2607—Circuits therefor
- G01R31/2608—Circuits therefor for testing bipolar transistors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0084—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring voltage only
-
- 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
-
- 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
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses an on-line testing circuit for conduction voltage drop of a main switching tube of a switching power supply, which is used for testing the conduction voltage drop of the main switching tube of the switching power supply circuit and is characterized by comprising an auxiliary power supply circuit which is connected in series between the grounding end of the switching power supply circuit and the C pole of the main switching tube in the switching power supply circuit; the auxiliary power supply circuit is externally connected with an auxiliary power supply. According to the invention, by additionally adding the DC9V power supply, the conduction voltage drop of the main switching tube of the switching power supply circuit can be accurately tested on line, compared with the traditional test method, the test accuracy is higher, and substantial help can be provided for the switching power supply to select the main switching tube.
Description
Technical Field
The invention relates to the technical field of electronics, in particular to a switching power supply main switching tube conduction voltage drop on-line test circuit.
Background
With the rise of consumer electronic products, more and more power adapters are matched with the consumer electronic products, a main switch tube is arranged in each power adapter, and the quality of the main switch tube is directly related to the quality of the whole power adapter. Therefore, when the power adapter is used, the conduction voltage drop of the main switch tube in the power adapter can be tested usually, and the proper main switch tube is selected when the power adapter is produced conveniently. However, when the traditional method is adopted to test the conduction voltage drop of the main switching tube, the error is large, and the judgment of the performance of the main switching tube by a tester is seriously influenced.
Disclosure of Invention
The invention aims to solve the problems and provides an on-line test circuit which is convenient to test and can test the conduction voltage drop of a main switching tube during actual operation.
The purpose of the invention is realized by the following technical scheme: an on-line test circuit for conduction voltage drop of a main switching tube of a switching power supply is used for testing the conduction voltage drop of the main switching tube of the switching power supply circuit and comprises an auxiliary power supply circuit which is connected in series between the grounding end of the switching power supply circuit and the C pole of the main switching tube in the switching power supply circuit; the auxiliary power supply circuit is externally connected with an auxiliary power supply.
Further, the auxiliary power supply circuit comprises a diode D3, a diode D4, a resistor R2 and a capacitor C3; the K pole of the diode D3 is connected with the C pole of a main switching tube in the switching power supply circuit, the A pole of the diode is used as a conduction voltage drop test point, the A pole of the diode D4 is connected with the A pole of the diode D3, the K pole of the diode is connected with an auxiliary power supply, the resistor R2 is connected with the diode D4 in parallel, and the capacitor C3 is connected between the A pole of the diode D4 and the grounding end of the switching power supply circuit in series; the A pole of the diode D3 and the grounding end of the switch power supply circuit are connected with an external oscilloscope probe.
The auxiliary power supply is 9V direct current.
The switching power supply circuit comprises a voltage supply circuit and a control circuit connected with the voltage supply circuit; the voltage supply circuit comprises a transformer T1, a diode D2, a capacitor C1, a polarity capacitor CE2, a diode D1, a pole A, a pole K, a pole B and a pole C1, wherein the pole A is connected with the dotted terminal of a primary winding of the transformer T1, the pole K is connected with the dotted terminal of a primary winding of the transformer T1 after passing through a resistor R1, the capacitor C1 is connected with the resistor R1 in parallel, the pole C is connected with the dotted terminal of the primary winding of the transformer T1, the negative pole C2 is grounded, the pole A is connected with the dotted terminal of a secondary winding of the transformer T1, and the pole K is connected with the dotted terminal of a secondary winding of the transformer T1 after passing through a polarity capacitor CE 1; the anode of the polar capacitor CE1 is connected with the K pole of a diode D1; the synonym terminal of the primary winding of the transformer T1 is connected with the external power supply.
The control circuit comprises a PWM (pulse-width modulation) timing control chip U1, a main switching tube Q1, a capacitor C2 connected between an FB pin of the PWM timing control chip U1 and the negative electrode of a polar capacitor CE2 in series, a photoelectric coupler U1B with a collector connected with the FB pin of the PWM timing control chip U1 and an emitter connected with the negative electrode of a polar capacitor CE2, a polar capacitor CE3 with an anode connected with a VDD (voltage-VDD) pin of the PWM timing control chip U1 and a negative electrode connected with the negative electrode of a polar capacitor CE2, and a resistor RS1 connected between the emitter of the main switching tube Q1 and the negative electrode of the polar capacitor CE2 in series; the C pole of the main switching tube Q1 is connected with the A pole of a diode D2, and the B pole of the main switching tube Q1 is connected with the GATE pin of a PWM timing control chip U1; the GND pin of the PWM timing control chip U1 is connected to the negative terminal of the polarity capacitor CE 2.
Compared with the prior art, the invention has the following advantages and beneficial effects: according to the invention, by additionally adding the DC9V power supply, the conduction voltage drop of the main switching tube of the switching power supply circuit can be accurately tested on line, compared with the traditional test method, the test accuracy is higher, and substantial help can be provided for the switching power supply to select the main switching tube.
Drawings
Fig. 1 is a circuit configuration diagram of the present invention.
Detailed Description
The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.
Examples
As shown in fig. 1, the invention discloses an on-line testing circuit for conduction voltage drop of a main switching tube of a switching power supply, which is used for testing the conduction voltage drop of the main switching tube in the switching power supply circuit so as to judge whether the main switching tube is good or not.
Specifically, as shown in fig. 1, the test circuit includes an auxiliary power circuit connected in series between a ground terminal of the switching power circuit and a C-pole of a main switching transistor in the switching power circuit, and the auxiliary power circuit is externally connected to an auxiliary power supply.
The switching power supply circuit comprises a voltage supply circuit and a control circuit connected with the voltage supply circuit. Specifically, the voltage supply circuit comprises a transformer T1, a polar capacitor CE2, a capacitor C1, a resistor R1, a diode D2, a diode D1 and a polar capacitor CE 1. When the diode D2 is connected, the A pole is connected with the dotted terminal of the primary winding of the transformer T1, and the K pole is connected with the dotted terminal of the primary winding of the transformer T1 after passing through the resistor R1. The capacitor C1 is connected in parallel with the resistor R1. The anode of the polar capacitor CE2 is connected to the synonym terminal of the primary winding of the transformer T1, and the cathode thereof is grounded. The diode D1 has its a pole connected to the dotted terminal of the secondary winding of the transformer T1 and its K pole connected to the positive pole of the linear capacitor CE 1. The negative electrode of the linear capacitor CE1 is connected to the synonym terminal of the secondary winding of the transformer T1. The synonym terminal of the primary winding of the transformer T1 is connected with the external power supply.
The control circuit comprises a PWM (pulse-width modulation) timing control chip U1, a main switching tube Q1, a capacitor C2, a photoelectric coupler U1B, a polar capacitor CE3 and a resistor RS 1. When connected, the capacitor C2 is connected in series between the FB pin of the PWM timing control chip U1 and the negative electrode of the polarity capacitor CE 2. The collector of the photocoupler U1B is connected to the FB pin of the PWM timing control chip U1, and the emitter thereof is connected to the negative electrode of the polarity capacitor CE 2. The positive electrode of the polar capacitor CE3 is connected to the VDD pin of the PWM timing control chip U1, and the negative electrode thereof is connected to the negative electrode of the polar capacitor CE 2. The resistor RS1 is connected in series between the emitter of the main switch tube Q1 and the cathode of the polar capacitor CE 2. In addition, the C pole of the main switch tube Q1 is connected with the A pole of the diode D2, and the B pole of the main switch tube Q1 is connected with the GATE pin of the PWM timing control chip U1; the GND pin of the PWM timing control chip U1 is connected to the negative terminal of the polarity capacitor CE 2.
The auxiliary power supply circuit comprises a diode D3, a diode D4, a resistor R2 and a capacitor C3. The K pole of the diode D3 is connected with the C pole of the main switch tube Q1, the A pole of the diode D4 is used as a conducting voltage drop test point, the A pole of the diode D3 is connected with the A pole of the diode D3, and the K pole of the diode D4 is connected with the auxiliary power supply. The resistor R2 is connected in parallel with the diode D4, and the capacitor C3 is connected in series between the A pole of the diode D4 and the GND pin of the PWM timing control chip U1. The A pole of the diode D3 and the grounding end of the switch power supply circuit are connected with an external oscilloscope probe. The auxiliary power supply is 9V direct current.
During operation, DC300V voltage is filtered by a polar capacitor CE2 and then is added to the C pole of a main switch tube Q1 through a primary winding of a transformer T1, the main switch tube Q1 performs switching action through a PWM time sequence control chip U1 to drive a transformer T1 to perform power supply conversion, meanwhile, DC9V voltage is limited by a resistor R2 and filtered by a capacitor C3 after a diode D4 performs anti-backflow treatment, at the moment, voltage is detected by an oscilloscope probe between a conduction voltage drop test point and a GND pin of the PWM time sequence control chip U1, and oscilloscope waveform voltage between the conduction voltage drop test point and the GND pin of the PWM time sequence control chip U1 is voltage drop reflected when the main switch tube Q1 is conducted. The D3 is a separate diode between the conduction voltage drop test point and the pole of the main switch Q1C. Because the reflected voltage of the switching power supply circuit is far higher than the normal conduction voltage drop of the main switching tube Q1, a large error exists when the conduction voltage drop of the main switching tube is tested by a traditional test method; and because the low voltage has smaller precision error value, by utilizing the principle of voltage equal difference, the invention can reduce the error by additionally adding a smaller DC9V power supply and improve the testing precision of the conduction voltage drop of the main switch tube Q1. For example, the conduction voltage drop of the main switch tube is 1.5V, the reflected voltage of the switching power supply circuit is 600V, if the test error is 1%, the error value is 6V, which is certainly a large error value compared with the conduction voltage drop of the main switch tube of 1.5V; the invention has 1% testing error and only 0.09V error value by adding a DC9V power supply, and the obvious error is higher than the smaller testing precision compared with the conduction voltage drop of the main switch tube of 1.5V.
As described above, the present invention can be preferably realized.
Claims (5)
1. An on-line test circuit for conduction voltage drop of a main switching tube of a switching power supply is used for testing the conduction voltage drop of the main switching tube of the switching power supply circuit and is characterized by comprising an auxiliary power supply circuit which is connected in series between the grounding end of the switching power supply circuit and the C pole of the main switching tube in the switching power supply circuit; the auxiliary power supply circuit is externally connected with an auxiliary power supply.
2. The on-line testing circuit for conduction voltage drop of the main switching tube of the switching power supply as claimed in claim 1, wherein the auxiliary power supply circuit comprises a diode D3, a diode D4, a resistor R2, a capacitor C3; the K pole of the diode D3 is connected with the C pole of a main switching tube in the switching power supply circuit, the A pole of the diode is used as a conduction voltage drop test point, the A pole of the diode D4 is connected with the A pole of the diode D3, the K pole of the diode is connected with an auxiliary power supply, the resistor R2 is connected with the diode D4 in parallel, and the capacitor C3 is connected between the A pole of the diode D4 and the grounding end of the switching power supply circuit in series; the A pole of the diode D3 and the grounding end of the switch power supply circuit are connected with an external oscilloscope probe.
3. The on-line testing circuit for conduction voltage drop of the main switching tube of the switching power supply according to claim 1 or 2, wherein the auxiliary power supply is 9V direct current.
4. The on-line testing circuit for the conduction voltage drop of the main switching tube of the switching power supply according to claim 1, wherein the switching power supply comprises a voltage supply circuit and a control circuit connected with the voltage supply circuit; the voltage supply circuit comprises a transformer T1, a diode D2, a capacitor C1, a polarity capacitor CE2, a diode D1, a pole A, a pole K, a pole B and a pole C1, wherein the pole A is connected with the dotted terminal of a primary winding of the transformer T1, the pole K is connected with the dotted terminal of a primary winding of the transformer T1 after passing through a resistor R1, the capacitor C1 is connected with the resistor R1 in parallel, the pole C is connected with the dotted terminal of the primary winding of the transformer T1, the negative pole C2 is grounded, the pole A is connected with the dotted terminal of a secondary winding of the transformer T1, and the pole K is connected with the dotted terminal of a secondary winding of the transformer T1 after passing through a polarity capacitor CE 1; the anode of the polar capacitor CE1 is connected with the K pole of a diode D1; the synonym terminal of the primary winding of the transformer T1 is connected with the external power supply.
5. The on-line testing circuit for conduction voltage drop of the main switching tube of the switching power supply as claimed in claim 4, wherein said control circuit comprises a PWM timing control chip U1, a main switching tube Q1, a capacitor C2 connected in series between the FB pin of the PWM timing control chip U1 and the negative electrode of a polarity capacitor CE2, a photocoupler U1B having a collector connected with the FB pin of the PWM timing control chip U1 and an emitter connected with the negative electrode of a polarity capacitor CE2, a polarity capacitor CE3 having an anode connected with the VDD pin of the PWM timing control chip U1 and a negative electrode connected with the negative electrode of a polarity capacitor CE2, and a resistor RS1 connected in series between the emitter of the main switching tube Q1 and the negative electrode of the polarity capacitor CE 2; the C pole of the main switching tube Q1 is connected with the A pole of a diode D2, and the B pole of the main switching tube Q1 is connected with the GATE pin of a PWM timing control chip U1; the GND pin of the PWM timing control chip U1 is connected to the negative terminal of the polarity capacitor CE 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111067353.XA CN113655363A (en) | 2021-09-13 | 2021-09-13 | On-line testing circuit for conduction voltage drop of main switching tube of switching power supply |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111067353.XA CN113655363A (en) | 2021-09-13 | 2021-09-13 | On-line testing circuit for conduction voltage drop of main switching tube of switching power supply |
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| CN113655363A true CN113655363A (en) | 2021-11-16 |
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| CN202111067353.XA Pending CN113655363A (en) | 2021-09-13 | 2021-09-13 | On-line testing circuit for conduction voltage drop of main switching tube of switching power supply |
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005304210A (en) * | 2004-04-14 | 2005-10-27 | Renesas Technology Corp | Power supply driver apparatus and switching regulator |
| US20060187688A1 (en) * | 2003-11-26 | 2006-08-24 | Mamoru Tsuruya | Switching power supply apparatus |
| CN102468761A (en) * | 2010-11-16 | 2012-05-23 | 海洋王照明科技股份有限公司 | Switch power supply |
| US20180076724A1 (en) * | 2016-09-15 | 2018-03-15 | Fuji Electric Co., Ltd. | Switching power supply |
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| CN108896899A (en) * | 2018-07-23 | 2018-11-27 | 广东志高暖通设备股份有限公司 | A kind of integrated switch pipe over-current detection circuit |
| CN208479166U (en) * | 2018-08-09 | 2019-02-05 | 上海奉天电子股份有限公司 | A kind of high-precision overvoltage/undervoltage detection control circuit |
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| US20200366279A1 (en) * | 2019-05-13 | 2020-11-19 | Shanghai Jiao Tong University | On-line monitoring system for measuring on-state voltage drop of power semiconductor devices |
-
2021
- 2021-09-13 CN CN202111067353.XA patent/CN113655363A/en active Pending
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| US20060187688A1 (en) * | 2003-11-26 | 2006-08-24 | Mamoru Tsuruya | Switching power supply apparatus |
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| CN208479166U (en) * | 2018-08-09 | 2019-02-05 | 上海奉天电子股份有限公司 | A kind of high-precision overvoltage/undervoltage detection control circuit |
| CN208754183U (en) * | 2018-10-17 | 2019-04-16 | 威胜集团有限公司 | Power circuit and its indoor display unit based on MicroUSB power supply |
| US20200366279A1 (en) * | 2019-05-13 | 2020-11-19 | Shanghai Jiao Tong University | On-line monitoring system for measuring on-state voltage drop of power semiconductor devices |
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