Dell USA L P

Nathan Wiscombe

Alan E Brown

Victor K Pecone

Ronald D Shaw

Arthur Lopez

A feedback sensing system including a control circuit for detecting power failure of either power supply, and for controlling first and second switch circuits to modify the feedback sensing path of the other supply to the output load. In this manner, when one power supply fails, the feedback sensing path of the other power supply is rerouted to the output node to directly monitor and regulate the voltage across the load. Each switch circuit preferably operates to switch between two nodes along the respective output paths of the power supply, including a first node located before the current control device and a second node located between the current control device and the load. In one embodiment, each switch circuit includes two switches operated in a mutually-exclusive manner. In another embodiment, each switch circuit includes a relatively low value resistive device coupled between the output sense input and the first node, and a switch coupled between the output sense input and the second node for swamping the resistive device when activated or otherwise turned on.

Method and apparatus for modifying feedback sensing for a redundant

A power loss detection system for a power supply including a main converter for providing regulated power, an activation circuit for mining on and off the main converter based on an active low activation signal, a standby power circuit for providing a standby power signal, and an internal pullup resistor coupled between the standby power and activation signals. The power supply asserts a power status signal indicative of the status of regulated power. Alternatively, an external detection circuit monitors the regulated power from the power supply and asserts a power loss signal indicative thereof. The control circuit asserts the activation signal low to turn on the main converter or floats the activation signal to turn off the main converter. If the power good or power loss signal indicates loss of regulated power, the control circuit floats the activation signal. If the activation signal goes or remains low after the activation signal is floated, then the power source has failed. If the activation signal is pulled high, then the power supply has failed. If the power supply has failed, then the control circuit asserts a failure signal indicative thereof. The present invention is particularly advantageous in a redundant power supply system for supplying power to a computer system, where both power supplies provide standby power.

Method and apparatus for distinguishing between failure of a power

A computer is provided with a redundant power supply system using a plurality of power supply boxes having generally conventional, off-the-shelf configurations. The computer includes a housing having a wall opening spaced apart from and facing the side of a paralleling type circuit board having mounted thereon a plurality of AC electrical connectors and a spaced plurality of DC electrical connectors. The power supply boxes are mounted on carrier structures slidably received in the computer housing for drawer-like movement through the housing wall opening toward and away from the circuit boards. Each power supply box has an external wire bundle with blind mate DC electrical connectors mounted on the outer ends of its leads and supported by the carrier structure for mating connection with their associated circuit board connectors when the carrier structure is moved into adjacency with its associated circuit board. The carrier structure also supports an AC connector structure which is mated with its associated circuit board connector in response to such movement of the carrier structure. A switch carded by each carrier structure is operative to selectively enable and disable its associated power supply box and releasably lock the carrier structure to the computer housing.

Computer power supply apparatus

A method and apparatus for balancing shared power supplies or regulating a power supply device includes disposing a transistor (310) in series with a power supply current that is supplied to a load resistor (316) The gate of the transistor (310) is controlled by a control circuit (320) to set the gate-to-source voltage thereon to define a desired current therethrough. The voltage across the transistor (310) is measured with a voltage detector (322) and then a current conversion device (324) is operable to use a look up table to determine from the gate voltage on the transistor (310) what the impedance across the drain-to-source is and then calculate the current. This current is then utilized by the control circuit (320) to control the current through transistor 310. This therefore allows transistor (310) to both provide the control operation and provide the sensing operation, thus eliminating the requirement for a separate sense resistor.

Growing community of inventors

Cedar Park, TX, United States of America

Nathan Wiscombe