Switching power supply burn in test circuit

A switching power supply burn in test circuit includes an AC/DC bidirectional converter, a DC/DC load and a first wire connecting end. The AC/DC bidirectional converter has an AC terminal connected to a power grid of the mains power, and a DC terminal connected to the first wire connecting end. The DC/DC load has an output terminal connected to the first wire connecting end. When the power supply to be tested is a DC/DC switching power supply, the input terminal of the DC/DC switching power supply is connected to the first wire connecting end, and its output terminal is connected to the input terminal of the DC/DC load. When the power supply to be tested is an AC/DC switching power supply, the input terminal of the AC/DC switching power supply is connected to the mains power and its output terminal is connected to the input terminal of the DC/DC load.

FIELD OF INVENTION

The present invention relates to the technical field of power supply burn in test, in particular to a power-saving burn in test for a switching power supply.

BACKGROUND OF INVENTION

1. Description of the Related Art

In general, a conventional switching power supply burn in test is performed by using a high power resistor as load, and electric energy is consumed and converted into heat by the resistor, and the test wastes tremendous energy unnecessarily.

To reduce the aforementioned waste of electric energy of the switching power supply during burn in test, an improved test circuit as shown inFIG. 1is used for the switching power supply burn in test, whereinFIG. 1ashows that the power supply to be tested is an AC/DC power supply, andFIG. 1bshows that the power supply to be tested is a DC/DC power supply, wherein the DC/AC load and the DC/DC load are AC/DC converter and DC/DC converter respectively and they are used to substitute the high power resistor as a load and feeds back the electric energy to the input terminal of the power supply to be tested for a reuse, so as to reduce the waste of electric energy.

However, the aforementioned solution divides the power supply to be tested into the AC/DC power supply and the DC/DC power supply and uses different circuits as shown inFIGS. 1aand 1bfor the burn in test, so that the test is relatively more troublesome and has a poor compatibility, so that manufacturers have to buy two different sets of testing equipments which will increase the cost. Therefore, two other improved solutions as shown inFIG. 2are introduced. InFIG. 2a, when the power supply to be tested is a DC/DC power supply, K1is open, and K2is closed, and the AC/DC power supply receives power from utility grid and coverts the power into a direct current DC1required by the test, and the direct current DC1is outputted to the DC/DC power supply to be tested, and then the DC/DC power supply to be tested converts the direct current DC1into a direct current DC2and outputs the direct current DC2to the DC/DC load, and the DC/DC load converts the direct current DC2into the direct current DC1which is fed back to the input terminal of the DC/DC power supply to be tested for a reuse. When the power supply to be tested is an AC/DC power supply, K1is closed, and K2is open, and the utility grid supplies power to the AC/DC power supply to be tested for testing, and the AC/DC power supply to be tested converts the mains power into a direct current DC2which is outputted to the DC/DC load, and the DC/DC load converts the direct current DC2into the direct current DC1which is outputted to the DC/AC load, and the DC/AC load converts the DC into AC which is fed back to the power grid for a reuse. In the improved solution as shown inFIG. 2b, the switches K1and K2are removed, and when the power supply to be tested is a DC/DC power supply, the current flow direction is AC/DC power supply→DC/DC power supply to be tested→DC/DC load→DC/AC load→AC/DC power supply to achieve the effect of reusing the electric energy. When the power supply to be tested is an AC/DC power supply, the current flow direction is power grid→AC/DC power supply to be tested→DC/DC load→DC/AC load→power grid to achieve the effect of reusing the electric energy. Although the two improved solutions as shown inFIG. 2can overcome the compatibility issue and test both DC/DC power supply and AC/DC power supply by one circuit, yet there are still drawbacks. The improved solution as shown inFIG. 2ahas a relatively more complicated circuit structure and requires manually switching K1and K2and thus may go wrong easily. The improved solution as shown inFIG. 2bcan simplify the structure by omitting the switches K1and K2, yet the testing of both DC/DC power supply and AC/DC power supply has two loads (the DC/DC load and the DC/AC load), and thus wasting electric energy.

2. Summary of the Invention

Therefore, it is a primary objective of the present invention to overcome the drawbacks of the prior art by providing a switching power supply burn in test circuit with the features of good compatibility and simple structure and capable of reducing the waste of electric energy.

To achieve the aforementioned and other objectives, the present invention provides a switching power supply burn in test circuit, comprising: an AC/DC bidirectional converter, a DC/DC load and a first wire connecting end, and the AC/DC bidirectional converter having an AC terminal coupled to a power grid of the mains power, and the DC terminal being coupled to a first wire connecting end, and the DC/DC load having an output terminal coupled to the first wire connecting end, and when a power supply to be tested is a DC/DC switching power supply, an input terminal of the DC/DC switching power supply to be tested is coupled to the first wire connecting end and an output terminal of the DC/DC switching power supply to be test is coupled to an input terminal of the DC/DC load, and the AC/DC bidirectional converter rectifies the mains power into a direct current DC1and outputs the direct current DC1from the DC terminal of the AC/DC bidirectional converter through the first wire connecting end to the input terminal of the DC/DC switching power supply to be tested, and the DC/DC switching power supply to be tested converts the direct current DC1into a direct current DC2and outputs the direct current DC2to the input terminal of the DC/DC load, and the DC/DC load converts the direct current DC2into the direct current DC1and outputs the direct current DC1from the first wire connecting end to the input terminal of the DC/DC switching power supply to be tested for a reuse; when the power supply to be tested is an AC/DC switching power supply, an input terminal of the AC/DC switching power supply to be tested is coupled to a power grid of the mains power, and the output terminal of the AC/DC switching power supply to be tested is coupled to the input terminal of the DC/DC load, and the AC/DC switching power supply to be tested rectifies the mains power into a direct current DC2and outputs the direct current DC2to the input terminal of the DC/DC load, and the DC/DC load converts the direct current DC2into the direct current DC1and outputs the direct current DC1through the first wire connecting end to the DC terminal of the AC/DC bidirectional converter, and the AC/DC bidirectional converter converts the direct current DC1into an alternate current AC and outputs the alternate current AC from the AC terminal of the AC/DC bidirectional converter to a power grid of the mains power for a reuse.

The AC/DC bidirectional converter can rectify the alternate current (AC) into the direct current (DC) and also can convert the DC into AC to achieve the bidirectional flow of the electric energy, and the present invention uses this feature to simplify the switching power supply burn in test circuit simply comprised of the AC/DC bidirectional converter and the DC/DC load and test the DC/DC power supply and the AC/DC power supply with a good compatibility and one load less, so as to reduce the power consumption and the waste of electric energy.

Preferably, the direct current DC1has a voltage value greater than the voltage value of the direct current DC2.

Preferably, the DC/DC load is a boost circuit.

Preferably, the AC/DC bidirectional converter comprises a plurality of switching tubes Q11-Q16, a plurality of capacitors C11-C12, an inductor L11and a transformer T11, and the switching tubes Q11and Q13are connected in series with each other and then in parallel with the capacitor C11, and the switching tubes Q12and Q14are connected in series and then in parallel with the capacitor C11, and the transformer T11has a primary coil connected in series with the switching tube Q15and then in parallel with the capacitor C11and a secondary coil connected in series with the switching tube Q16and then in parallel with the capacitor C12, and the inductor L11has an end connected to the contact point of the switching tubes Q11and Q13and the other end serving as a first terminal of an AC terminal of the AC/DC bidirectional converter connected to a fire wire of the mains power, and the contact point of the switching tubes Q12and Q14serving as a second terminal of the AC terminal of the AC/DC bidirectional converter connected a zero line of the mains power, and both ends of the capacitor C12serve as a positive electrode and a negative electrode of the AC/DC bidirectional converter DC terminal respectively. The AC/DC bidirectional converter is applicable for a single-phase mains power or a small power.

Preferably, the AC/DC bidirectional converter comprises a plurality of switching tubes Q21-Q34, a plurality of inductors L21-L24, a plurality of capacitors C21-C22, a transformer T21and a diode D21, and the inductor L24is a conjugate inductor, and the switching tubes Q21and Q24are connected in series with each other and then in parallel with the capacitor C21, and the switching tubes Q22and Q25are connected in series with each other and then in parallel with the capacitor C21, and the switching tubes Q23and Q26are connected in series with each other and then in parallel with the capacitor C21, and a third terminal of the inductor L24is connected to a first terminal of the capacitor C21, and the switching tubes Q27and Q29are connected in series with each other and then in parallel with a fourth terminal of the inductor L24and a second terminal of the capacitor C21, and the switching tubes Q28and Q30are connected in series with each other and then in parallel with a further terminal of the inductor L24and a second terminal of the capacitor C21, and the switching tubes Q31and Q33are connected in series with each other and then in parallel with the capacitor C22, and the switching tubes Q32and Q34are connected in series with each other and then in parallel with the capacitor C22, and both ends of the primary coil of the transformer T21are connected to the contact point of the switching tubes Q27and Q29and the contact point of the switching tubes Q28and Q30respectively and both ends of the secondary coil of the transformer T21are connected to the contact point of the switching tubes Q31and Q33and the contact point of the switching tubes Q32and Q34respectively, and the second terminal of the inductor L24is connected to an end of the capacitor C22and the first terminal is connected to the other end of the capacitor C22through the diode D21, and an end of the inductor L21is connected to the contact point of the switching tubes Q21and Q24and the other end of the inductor L32serves as a first terminal of the AC/DC bidirectional converter connected a phase line of the three-phase mains power A, and an end of the inductor L22is connected to the contact point of the switching tubes Q22and Q25and the other end of the inductor L22serves as a second terminal of the AC terminal of the AC/DC bidirectional converter connected to a phase line of the three-phase mains power B, and an end of the inductor L23is connected to the contact point of the switching tubes Q23and Q26, and the other end of the inductor L23serves as a third terminal of the AC terminal of the AC/DC bidirectional converter connected to a phase line of the three-phase mains power C, and both ends of the capacitor C22serve as a positive electrode and a negative electrode of the DC terminal of the AC/DC bidirectional converter. The AC/DC bidirectional converter is applicable for a three-phase mains power or a large power.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

To make it easier for our examiner to understand the objective of the invention, its structure, innovative features, and performance, we use a preferred embodiment together with the attached drawings for the detailed description of the invention. Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

With reference toFIG. 3for a switching power supply burn in test circuit of a preferred embodiment of the present invention, the switching power supply burn in test circuit comprises an AC/DC bidirectional converter, a DC/DC load and a first wire connecting end a. Preferably, the DC/DC load is a boost circuit as shown inFIG. 6, and the AC/DC bidirectional converter has an AC terminal connected to a power grid of the mains power and a DC terminal connected to the first wire connecting end a, and the DC/DC load has an output terminal connected to the first wire connecting end a. When the power supply to be tested is a DC/DC switching power supply, the input terminal of the DC/DC switching power supply is connected to the first wire connecting end a and the output terminal of the DC/DC switching power supply is connected to the input terminal of the DC/DC load, and the AC/DC bidirectional converter rectifies the mains power into a direct current DC1and outputs the direct current DC1from the first wire connecting end a to the input terminal of the DC/DC switching power supply to be tested, and the DC/DC switching power supply to be tested converts the direct current DC1into a direct current DC2and outputs the direct current DC2to the input terminal of the DC/DC load, wherein the direct current DC1has a voltage value greater than the voltage value of the direct current DC2, and the DC/DC load converts the direct current DC2into a direct current DC1and outputs the direct current DC1from the first wire connecting end a to the input terminal of the DC/DC switching power supply to be tested for a reuse. When the power supply to be tested is an AC/DC switching power supply, the AC/DC switching power supply to be tested has an input terminal connected to a power grid of the mains power and an output terminal connected to the input terminal of the DC/DC load, and the AC/DC switching power supply to be tested rectifies the mains power into a direct current DC2and outputs the direct current DC2to the input terminal of the DC/DC load, and the DC/DC load converts the direct current DC2into the direct current DC1and outputs the direct current DC1from the first wire connecting end a to the DC terminal of the AC/DC bidirectional converter, and the AC/DC bidirectional converter converts the direct current DC1into AC and outputs the AC from its AC terminal to a power grid of the mains power for a reuse. The AC/DC bidirectional converter can rectify the alternate current (AC) into the direct current (DC) and also can convert the DC into AC to achieve the bidirectional flow of the electric energy, and the present invention uses this feature to simplify the switching power supply burn in test circuit simply comprised of the AC/DC bidirectional converter and the DC/DC load and test the DC/DC power supply and the AC/DC power supply with a good compatibility and one load less, so as to reduce the power consumption and the waste of electric energy.

With reference toFIG. 4for an AC/DC bidirectional converter in accordance with a preferred embodiment of the present invention, the AC/DC bidirectional converter comprises a plurality of switching tubes Q11-Q16, a plurality of capacitors C11-C12, an inductor L11and a transformer T11, and the switching tubes Q11and Q13are connected in series with each other and then in parallel with the capacitor C11, and the switching tubes Q12and Q14are connected in series and then in parallel with the capacitor C11, and the transformer T11has a primary coil connected in series with the switching tube Q15and then in parallel with the capacitor C11and a secondary coil connected in series with the switching tube Q16and then in parallel with the capacitor C12, and the inductor L11has an end connected to the contact point of the switching tubes Q11and Q13and the other end serving as a first terminal of an AC terminal of the AC/DC bidirectional converter connected to a fire wire of the mains power, and the contact point of the switching tubes Q12and Q14serving as a second terminal of the AC terminal of the AC/DC bidirectional converter connected a zero line of the mains power, and both ends of the capacitor C12serve as a positive electrode and a negative electrode of the AC/DC bidirectional converter DC terminal respectively. The AC/DC bidirectional converter is applicable for a single-phase mains power or a small power.

With reference toFIG. 5for an AC/DC bidirectional converter in accordance with a preferred embodiment of the present invention, the AC/DC bidirectional converter comprises a plurality of switching tubes Q21-Q34, a plurality of inductors L21-L24, a plurality of capacitors C21-C22, a transformer T21and a diode D21, and the inductor L24is a conjugate inductor, and the switching tubes Q21and Q24are connected in series with each other and then in parallel with the capacitor C21, and the switching tubes Q22and Q25are connected in series with each other and then in parallel with the capacitor C21, and the switching tubes Q23and Q26are connected in series with each other and then in parallel with the capacitor C21, and a third terminal of the inductor L24is connected to a first terminal of the capacitor C21, and the switching tubes Q27and Q29are connected in series with each other and then in parallel with a fourth terminal of the inductor L24and a second terminal of the capacitor C21, and the switching tubes Q28and Q30are connected in series with each other and then in parallel with a further terminal of the inductor L24and a second terminal of the capacitor C21, and the switching tubes Q31and Q33are connected in series with each other and then in parallel with the capacitor C22, and the switching tubes Q32and Q34are connected in series with each other and then in parallel with the capacitor C22, and both ends of the primary coil of the transformer T21are connected to the contact point of the switching tubes Q27and Q29and the contact point of the switching tubes Q28and Q30respectively and both ends of the secondary coil of the transformer T21are connected to the contact point of the switching tubes Q31and Q33and the contact point of the switching tubes Q32and Q34respectively, and the second terminal of the inductor L24is connected to an end of the capacitor C22and the first terminal is connected to the other end of the capacitor C22through the diode D21, and an end of the inductor L21is connected to the contact point of the switching tubes Q21and Q24and the other end of the inductor L32serves as a first terminal of the AC/DC bidirectional converter connected a phase line of the three-phase mains power A, and an end of the inductor L22is connected to the contact point of the switching tubes Q22and Q25and the other end of the inductor L22serves as a second terminal of the AC terminal of the AC/DC bidirectional converter connected to a phase line of the three-phase mains power B, and an end of the inductor L23is connected to the contact point of the switching tubes Q23and Q26, and the other end of the inductor L23serves as a third terminal of the AC terminal of the AC/DC bidirectional converter connected to a phase line of the three-phase mains power C, and both ends of the capacitor C22serve as a positive electrode and a negative electrode of the DC terminal of the AC/DC bidirectional converter. The AC/DC bidirectional converter is applicable for a three-phase mains power or a large power.

The circuit structure and principle of the aforementioned two preferred embodiments of the AC/DC bidirectional converter are prior arts, and thus will not be repeated here, and the two AC/DC bidirectional converters may be selected according to the actual required situation.