Compaq Computer Corporation, Inc.

Other

Richard A Faulk

John C Schluter

Thanh Thien Tran

Richard E Walker

Michael E Schneider

David A Hulsebosch

Eddie B Braddy, Jr

J Howard Ho

A circuit and method for charging batteries while a power supply also powers a dynamically varying load. All power in excess of that required by the load is used by a power converter to charge the batteries. The circuit advantageously allows the load to change from external power to battery power without switching delays.

Battery charge control architecture for constant voltage maximum power

A planar-type magnetic structure in which two coils, on two poles of the same core, are separated by an open space which is wide enough and low enough that the air return flux, through the open space, completes the flux circuit for each coil. Thus the coupling coefficient between the two coils is very small, even though they are both mounted on a single continuous core of high-permeability material.

Planar magnetics with segregated flux paths

A universal battery pack in which an internal switch-mode power converter's control circuitry is powered from the battery side of the converter, rather than from the system side.

Converting battery module with battery-powered controller

A battery pack which contains an integral bidirectional up/down voltage converter, so that the voltage of the battery does not have to match the voltage of the system power lines at all. Thus a single battery pack can be used in different systems which have different power bus voltages.

Variable-voltage programmable battery module

A universal battery pack which contains an integral DC-DC switching power converter, with an asymmetric ripple-suppression topology which suppresses ripple at the power output terminals during discharging.

Ripple-suppressed converting battery module

A standardized and universal application-specific language for operation of any battery type where measured values of voltage, current, temperature, and/or power are used to control battery operation to optimize battery life, and prevent damage to the battery and the system in which it resides.

Battery control architecture with standardized language

A portable computer system which includes a modified C-7 power cord socket, which can receive either an AC power cord with a standard C-7 connector or a DC power cord with a modified C-7 connector. (However, the modified C-7 connector cannot be inserted into a standard C-7 socket.) Microswitches in the modified power cord socket detect the presence of the DC connector, and automatically adjust the power conversion circuit accordingly.

AC/DC portable power connecting architecture

Innovative systems and methods for advantageous use of a new isolated power converter topology, in which transformer isolation is provided by a very simple DC-DC converter operated in open-loop mode (with each switch running at a constant duty cycle of approximately 50%, to achieve an effective duty cycle of approximately 100%), and feedback or modulation is instead applied to a preconverter stage which also does power factor corrections. Since the isolation stage is operated at a constant duty cycle, distortion can be minimized and its efficiency can be fully optimized, with a simple circuit and small component count. Unlike a flyback converter, only a very small inductance is required. A simple control architecture is used with current control loop. The disclosed circuit tightly clamps the voltages on the switch and on the transformer, with no ringing nor overshoot.

System with open-loop DC-DC converter stage

A universal battery pack which contains an integral transformerless DC--DC switching power converter, with no DC connection between the battery and the power terminals. This provides inherent protection against overcurrent, and permits smaller fuse sizes to be used for a given current rating.

DC-isolated converting battery module

A current-mode control system for a switching power supply which provides logarithmic compensation to a peak primary current of a variable frequency, fully discontinuous switching power supply. A ramp voltage generator generates a ramp voltage that is furnished to a control circuit. The control circuit compares the voltage level of the ramp signal to the voltage level of a control voltage. The control voltage is provided by an error amplifier and is a function of an output voltage of the converter. The control circuit allows a primary switching current to exist in the converter until the ramp voltage renders the control voltage. The ramp voltage logarithmically compensates the peak of the primary current by adjusting the ramp voltage. This logarithmic compensation provides a relatively constant output power over a large input voltage range.

Logarithmic power compensation for a switching power supply

An isolation transformer comprises two core pieces mounted to cooperate to provide flux paths, one of the core pieces being shaped so that a central flux path is defined by a central leg of the core, at least two magnetically coupled windings surrounding the central flux path, and an isolation layer sandwiched between the windings.

Isolation transformers and isolation transformer assemblies

An auxiliary power transistor which is switched in common with the primary power transistor, and which isolates the voltage-monitoring circuit when the primary power transistor is off. Thus the signal for sensing the secondary current is connected only when the power transistor is turned on, and high voltages in the sensing logic are avoided. This is particularly advantageous for systems where the turn-off times of the power transistor are sought to be synchronized with current zero-crossings. This current-zero-crossing technique may be used to detect zero-crossings of current on a secondary-side switch.

Protected zero-crossing detection using switching transistor's

A universal battery pack which includes an integral power converter and a dynamically adjustable output voltage. The default output voltage is set by an optional resistor connection, which shifts the voltage-dividing ratio into the error amplifier. In a multiple-battery configuration, the output voltages of the separate battery modules are preferably set to slightly different values. Thus the battery module with the highest output voltage setting will be completely exhausted first. This results in automatic battery switchover, without requiring any control algorithm or logic for execution of the switchover.

Converting battery module with resistor programmation of default output

Converter topologies in which two separate switching transistors and two capacitors are used on the input side. Preferably the two transistors are switched alternately, to alternately pull down different nodes in an inductor-capacitor chain. Two capacitors are interposed in series between an input inductor on the input and a transformer primary winding. Preferably the two transistors are connected with their parasitic diodes in opposite senses, so that one can source current from a first node to ground when off, and the other can sink current from a second node to ground when off.

Converter topologies with multiple windings

An internal AC adapter which incorporates a space efficient EMI filter is positioned within a main chassis portion of a portable personal computer having at least one energy-demanding component also positioned within the main chassis portion. The internal AC adapter, which converts alternating current received from an alternating current main to direct current for transmission to the energy-demanding components, includes a first connector for electrically connecting the internal AC adapter to the alternating current main, a bridge rectifier circuit having an AC input side electrically connected to the first connector and a DC output side and a space efficient electromagnetic interference filter having an input side electrically connected to the DC output side of the bridge rectifier circuit and an output side. The bridge rectifier circuit converts alternating current received from the first connector to direct current for transmission to the electromagnetic interference filter. In turn, the electromagnetic interference filter includes at least one capacitative element for filtering noise from the direct current transmitted thereto by the bridge rectifier circuit. The filtered direct current is then transmitted to the energy-demanding components electrically connected to the output side of the electromagnetic interference filter. By placing the electromagnetic interference filter on the DC output side of the bridge rectifier circuit, reduced size capacitors such as a multilayer ceramic capacitor may be used as the capacitative element.

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Cypress, TX, United States of America

Richard A Faulk