Voltage drop cancellation

• US 8,552,878 B2
• Filed: 04/05/2010
• Issued: 10/08/2013
• Est. Priority Date: 04/05/2010
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Jordan, James D.
• Primary Examiner(s): Wu, Daniel
• Assistant Examiner(s): BAMERT, JOHN J
• Application Number:
  US12/754,434
• Publication Number:
  US 20110241893A1
• Time in Patent Office: 1,282 Days
• Field of Search: 340/333, 340/693.2, 307/66
• US Class Current: 340/663
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24

Abstract

An apparatus, system, and method are disclosed for bypassing a voltage drop. A protection module allows electric current to flow from an electric power storage device to a load. The protection module prevents electric current from flowing to the electric power storage device. The protection module includes a voltage drop between the electric power storage device and the load. A power source detection module detects an absence of electric power from an electric power source. The electric power source provides electric current to the load when electric power from the electric power source is present. A bypass module bypasses the protection module and the voltage drop in response to the power source detection module detecting the absence of electric power from the electric power source. A conservation module delivers, to the load, electric current flowing through the power source detection module.

Claims

1. An apparatus to bypass a voltage drop, the apparatus comprising:

a protection module configured to allow electric current to flow from a battery to a load and prevent electric current from flowing to the battery, the battery comprising a non-rechargeable battery, the protection module comprising a voltage drop between the battery and the load;

a power source detection module configured to detect an absence of electric power from an electric power source, the electric power source providing electric current to the load when electric power from the electric power source is present;

an output voltage detection module configured to detect that a voltage of the battery has fallen below a predefined level;

a bypass module configured to, in response to the power source detection module detecting the absence of electric power from the electric power source and the output voltage detection module detecting that the voltage of the battery has fallen below the predefined level, bypass the protection module such that the electric current from the battery reaches the load without the voltage drop of the protection module; and

a conservation module configured to deliver, to the load, electric current flowing through the power source detection module.

2. The apparatus of claim 1, wherein the voltage regulator supplies power to the load, the protection module is electrically connected to the input of the voltage regulator, the power source provides electric current to the load through the voltage regulator and the power source is connected to the input of the voltage regulator.

3. The apparatus of claim 1, wherein the conservation module is configured to deliver, to the load, electric current flowing through the output voltage detection module.

4. The apparatus of claim 1, wherein the output voltage detection module comprises a diode electrically coupled to a voltage divider in a series configuration, an output of the voltage divider electrically coupled to a driving circuit such that a voltage at the output of the voltage divider determines the predefined level for the output voltage detection module, an output of the driving circuit electrically coupled to the bypass module.

5. The apparatus of claim 1, further comprising a voltage regulator disposed between the protection module and the load, wherein the conservation module is configured to deliver the electric current flowing through the power source detection module to an output of the voltage regulator such that the load receives a portion of the electric current from the battery through the voltage regulator and a portion of the electric current from the battery through the power source detection module.

6. The apparatus of claim 1, wherein the power source detection module comprises a diode and a driving circuit, a cathode of the diode electrically coupled to the driving circuit, the cathode of the diode delivering electric current from the electric power source to the driving circuit when electric power from the electric power source is present, an output of the driving circuit electrically coupled to the bypass module.

7. The apparatus of claim 1, wherein the protection module comprises a blocking diode.

8. The apparatus of claim 1, wherein the load is selected from the group consisting of a real-time clock and a volatile memory device.

9. The apparatus of claim 1, further comprising a computing device, wherein the load is a component of the computing device.

10. The apparatus of claim 9, wherein the computing device comprises a blade server.

11. The apparatus of claim 1, further comprising a test module configured to temporarily interrupt electric current from the electric power source and measure a voltage at a point between the protection module and the load.

12. The apparatus of claim 11, wherein the test module is configured to alert a user in response to the voltage being below a predefined minimum threshold level.

13. A method to bypass a voltage drop, the method comprising:

allowing electric current to flow from a battery to a load and preventing electric current from flowing to the battery, the electric current having a voltage drop between the battery and the load, the battery comprising a non-rechargeable battery;

detecting an absence of electric power from an electric power source, the electric power source providing electric current to the load when electric power from the electric power source is present;

detecting that a voltage of the battery has fallen below a predefined level;

bypassing the voltage drop in response to detecting the absence of electric power from the electric power source and that the voltage of the battery has fallen below the predefined level, such that the electric current from the battery reaches the load without the voltage drop; and

delivering, to the load, electric current used to detect an absence of electric power from the electric power source.

14. The method of claim 13, further comprising delivering, to the load, electric current used to detect that the voltage of the battery has fallen below the predefined level.

15. An apparatus to bypass a voltage drop, the apparatus comprising:

a protection module configured to perform a diode function, an anode of the protection module electrically coupled to a battery, a cathode of the protection module electrically coupled to a load such that the protection module allows electric current to flow from the battery to the load and prevents electric current from flowing to the battery, the batter comprising a non-rechargeable battery, the protection module comprising a voltage drop between the battery and the load;

a power source detection module configured to detect an absence of electric power from an electric power source, the electric power source providing electric current to the load at the cathode of the protection module when electric power from the electric power source is present; and

an output voltage detection module configured to detect that a voltage of the battery has fallen below a predefined level;

a switch electrically coupled to the anode of the protection module and the cathode of the protection module such that the switch and the protection module are disposed in a parallel configuration, the switch configured to close in response to the power source detection module detecting the absence of electric power from the electric power source and the output voltage detection module detecting that the voltage of the battery has fallen below the predefined level, such that electric current from the battery reaches the load without the voltage drop of the protection module;

wherein electric current flowing through the power source detection module is delivered to the load.

16. The apparatus of claim 15, wherein electric current flowing through the output voltage detection module is delivered to the load.

17. The apparatus of claim 15, further comprising a voltage regulator electrically coupled between the cathode of the protection module and the load, wherein electric current flowing through the power source detection module is delivered to an output of the voltage regulator such that the load receives a portion of electric current from the battery through the voltage regulator and a portion of the electric current from the battery through the power source detection module.