ELECTRONIC LOAD

• US 20080150547A1
• Filed: 06/29/2007
• Published: 06/26/2008
• Est. Priority Date: 12/22/2006
• Status: Active Grant

• Current Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Inventors: LI, JUN, CHUANG, TSUNG-JEN, WONG, SHIH-FANG
• Granted Patent: US 7,466,162 B2
• Time in Patent Office: Days
• US Class Current: 324/555
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10

Abstract

An electronic load includes a current control circuit and an interface circuit. The current control circuit is used for receiving a voltage, and outputting a measured current. The interface circuit is coupled to said current control circuit, for receiving said measured current, and providing an interface for instruments. The current control circuit and the interface circuit are coupled to a power supply under test.

Claims

1. An electronic load comprising:

a current control circuit for receiving a control voltage and outputting a controllable measured current;

an interface circuit coupled to said current control circuit, for receiving said measured current, and providing an interface for instruments;

wherein the current control circuit and the interface circuit are coupled to a power supply under test.

2. The electronic load as claimed in claim 1, wherein the current control circuit comprises at least one power transistor;

the power transistor comprises a source terminal, a drain terminal, and a gate terminal;

the gate terminal is configured for coupling the control voltage;

the drain terminal is connected to the power supply under test; and

the source terminal is configured for outputting the measured current.

3. The electronic load as claimed in claim 2, wherein the current control circuit comprises at least one diode coupled to a drain terminal of the at least one power transistor, an anode of the diode is connected to the power supply under test, and a cathode of the diode is connected to the drain terminal of the power transistor.

4. The electronic load as claimed in claim 2, wherein the power transistor is either a power metal oxide semiconductor field effect transistor or an insulated gate bipolar transistor.

5. The electronic load as claimed in claim 1, wherein the electronic load further comprises a power circuit for outputting the control voltage to the current control circuit;

the power circuit comprises serially connected a DC input, a voltage-adjust unit and a switch unit;

the DC input is configured for coupling with an external DC voltage supplier, and receiving a DC voltage from the external DC voltage supplier;

the voltage-adjust unit is configured for outputting an adjusted voltage under adjustment; and

the switch unit is used for outputting the control voltage to the current control circuit at the occurrence that the switch unit is switched on.

6. The electronic load as claimed in claim 5, wherein the switch unit is either a bipolar junction transistor or a field effect transistor.

7. The electronic load as claimed in claim 5, wherein the voltage-adjust unit comprises a rheostat, the voltage-adjust unit outputs the adjusted voltage of the rheostat.

8. The electronic load as claimed in claim 7, wherein the voltage-adjust unit further comprises an adjustable shunt regulator, an outputted voltage of the adjustable shunt regulator is applied to the rheostat.

9. The electronic load as claimed in claim 5, wherein the power circuit further comprises a voltage-stabilize unit coupled to the DC input, for filtering out ripples in the DC voltage, and outputting a stabilized voltage to the voltage-adjust unit.

13. The system as claimed in claim 1, wherein the power circuit further comprises a DC input and a voltage-stabilize unit coupled to the DC input, the DC input is configured for being coupled to an external DC voltage supplier, and receiving a DC voltage from the external DC voltage supplier;

the voltage-stabilize unit is used for stabilizing the DC voltage, and outputting a stabilized voltage to the voltage-adjust unit.

10. A system comprising:

a power supply under test;

a load module coupled to the power supply, for testing the power supply, the load module comprising a current control circuit and an interface circuit; and

an instrument coupled to the interface circuit;

wherein the current control circuit is configured for outputting a measured current to the interface circuit in control of a control voltage.

11. The system as claimed in claim 10, wherein the system further comprises a power circuit for outputting the control voltage, the power circuit comprises serially connected a voltage-adjust unit and a switch unit;

the voltage-adjust unit is configured for outputting an adjusted voltage under adjustment; and

the switch unit is used for outputting the control voltage to the current control circuit at the occurrence that the switch unit is switched on.

12. The system as claimed in claim 11, wherein the switch unit is either a bipolar junction transistor or a field effect transistor.

14. The system as claimed in claim 11, wherein the power circuit further comprises an amplifier unit, the amplifier unit comprises an inverting input and a non-inverting input;

the inverting input of the amplifier unit is connected to an output end of the current control circuit, and the non-inverting input is connected with the voltage-adjust unit, for receiving the adjusted voltage.

15. The system as claimed in claim 11, wherein the voltage-adjust unit comprises a rheostat, the rheostat is used for being tuned, thus the voltage-adjust unit is able to output the adjusted voltage.

16. The system as claimed in claim 15, wherein the voltage-adjust unit further comprises an adjustable shunt regulator, an outputted voltage of the adjustable shunt regulator is applied to the rheostat.

17. The system as claimed in claim 10, wherein the current control circuit comprises at least one branch comprising at least one power transistor;

a source terminal of the at least one power transistor is configured for outputting the measured current to the interface circuit;

a drain terminal of the at least one power transistor is connected to the power supply under test through a diode, an anode of the diode is connected to the power supply under test, and a cathode of the diode is connected to the drain terminal of the at least one power transistor; and

a gate terminal of the at least one power transistor is configured for being coupled to the control voltage.

18. The system as claimed in claim 17, wherein the power transistor is either a power metal oxide semiconductor field effect transistor or an insulated gate bipolar transistor.

19. The system as claimed in claim 10, wherein the interface circuit comprises a plurality of shunt resistors connected in parallel with each other.

20. The system as claimed in claim 19, wherein the shunt resistors have a same resistance.