System and Method for Compensating for Cable Voltage Loss at Various Output Voltages

Patent metadata

Field	Value
Publication number	US-2016254752-A1
Application number	US-201514632518-A
Country	US
Kind code	A1
Filing date	Feb 26, 2015
Priority date	Feb 26, 2015
Publication date	Sep 1, 2016
Grant date	—

Abstract

A power adapter includes a primary side and a secondary side. The primary side rectifies an alternating current voltage. The secondary side is coupled to the primary side, provides a direct current voltage of a specific voltage level to a cable. The second side includes a sensing resistor, and a compensation circuit. The compensation circuit monitors a voltage level across the sensing resistor, and injects a current into the cable based on the voltage level across the sensing resistor.

First claim

What is claimed is:

1 . A power adapter comprising:
a cable to provide a direct current voltage of a specific voltage level to an information handling system; a sensing resistor coupled to the cable; and a compensation circuit coupled to the sensing resistor, the compensation circuit to monitor a voltage level across the sensing resistor, and to inject a current into the cable based on the voltage level across the sensing resistor.

2 . The power adapter of claim 1 , wherein the compensation circuit includes:
a plurality of switches, wherein different combinations of the switches are closed are based on the specific voltage level.

3 . The power adapter of claim 2 , wherein a higher number of the switches are closed in response to a higher specific voltage level.

4 . The power adapter of claim 2 , further comprising:
a microcontroller unit, the microcontroller unit to determine the specific voltage level based on a desired voltage level to be received at the information handling system, and to control the number of switches that are closed based on the specific voltage level.

5 . The power adapter of claim 4 , further comprising:
a variable resistor coupled to the compensation circuit, wherein the microcontroller unit is configured to vary an impedance of the variable resistor to change a voltage level of the direct current voltage.

6 . The power adapter of claim 1 , wherein a voltage drop occurs across the cable based on a current provided on the cable and on a resistance of the cable.

7 . The power adapter of claim 6 , wherein the current injected into the cable increases the direct current voltage provided to the cable to compensate for the voltage drop across the cable.

8 . A power adapter comprising:
a primary side to rectify an alternating current voltage; and a secondary side coupled to the primary side, the secondary side to provide a direct current voltage of a specific voltage level to a cable, the second side including:
a sensing resistor; and
a compensation circuit coupled to the sensing resistor, the compensation circuit to monitor a voltage level across the sensing resistor, and to inject a current into the cable based on the voltage level across the sensing resistor.

9 . The power adapter of claim 8 , wherein the compensation circuit includes:
a plurality of switches, wherein different combinations of the switches are closed are based on the specific voltage level.

10 . The power adapter of claim 9 , wherein a higher number of the switches are closed in response to a higher specific voltage level.

11 . The power adapter of claim 9 , further comprises:
a microcontroller unit, the microcontroller unit to determine the specific voltage level based on a desired voltage level to be received at an information handling system, and to control the number of switches that are closed based on the specific voltage level.

12 . The power adapter of claim 8 , wherein a voltage drop occurs across the cable based on a current provided on the cable and on a resistance of the cable.

13 . The power adapter of claim 12 , wherein the current injected into the cable increases the direct current voltage provided to the cable to compensate for the voltage drop across the cable.

14 . The power adapter of claim 12 , wherein the current injected into the cable causes the specific voltage level to be provided to an information handling system coupled to the cable.

15 . A method comprising:
determining a desired voltage level to be provided to an information handling system via a cable; monitoring a voltage level across a sensing resistor of the cable; and injecting a current into the cable based on the desired voltage level and the voltage level across the sensing resistor.

16 . The method of claim 15 further comprising:
determining whether the power adapter is connected to the information handling system via the cable prior to determining the desired voltage level.

17 . The method of claim 16 wherein a microcontroller unit determines whether the power adapter is connected to an information handling system.

18 . The method of claim 15 wherein a microcontroller unit determines the desired voltage level for the information handling system.

19 . The method of claim 15 further comprising:
closing a specific number of switches within a compensation circuit based on the desired voltage level to be provided to the information handling system.

20 . The method of claim 15 further comprising:
changing an impedance of a variable resistor based on the desired voltage level.

Assignees

• Dell Products Lp

Inventors

• Wood Iii Merle J
• Liao Anson
• Yu Jason

Classifications

• G01R19/0084

  Measuring voltage only · CPC title

• H02M3/22 Primary

  with intermediate conversion into AC · CPC title

• G06F1/305 Primary

  in the event of power-supply fluctuations · CPC title

• G01R15/14

  Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks · CPC title

• H02M3/28 Primary

  using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate AC · CPC title