Boschert, Inc.

Other

Hewlett-packard Company

Echelon Corporation

Tab Products Company, Inc.

Kenneth T Small

Herbert J Tanzer

Brian S Tsuyuki

Carl R Haynie

Donald D Baumann

G Michael Hey

A power distribution apparatus which utilizes relay devices to control the flow of power along power paths from an input terminal to one or more output terminals electrically coupled to the power paths. For each power path provided in the power distribution apparatus, the power distribution apparatus comprises one relay device and one or more output terminals associated with each power path. In operation, the relay device associated with each power path controls the flow of current from the input terminal to the output terminals electrically coupled to the power path. A switching assembly is electrically coupled to the power distribution apparatus for controlling the relay devices. When the switching assembly is activated, the relay devices are switched on and current is allowed to flow from the input terminal to the output terminals. When the switching assembly is deactivated, the relay devices are switched off and current is prevented from flowing from the input terminal to the output terminals. Preferably, the power distribution apparatus comprises a controller which controls the operation of the power distribution apparatus. When the switching assembly is activated and deactivated, the controller causes the relay devices to be closed and opened, respectively. Preferably, the controller switches the relay devices on and off in accordance with a predetermined timing sequence such that a time delay occurs from the time that one relay device is turned on or off before another relay device is switched on or off in the power distribution apparatus.

Power distribution apparatus comprising relay devices for controlling current flow along power paths of the power distribution apparatus

A power distribution unit adapted for mounting within an equipment enclosure including an inner rack. The power distribution unit includes at least one mounting hinge that is fixedly attached to the power distribution unit housing and which is adapted to fixedly mount the power distribution unit to the rack columns. The mounting hinge is pivotable such that the power distribution unit can be pivoted to an extended position to facilitate removal of removable modules of the equipment components mounted within the equipment enclosure.

Apparatus and method for mounting a power distribution unit within an equipment enclosure

A solid-state, PFC power converter for converting 3-phase AC to DC in a single, isolated conversion step, using 3 forward converters. Converter outputs share a common output choke, permitting operation at low instantaneous AC input voltage. Each forward converter is 'duty' modulated proportional to its rectified AC input voltage, producing unity input power factor. The constant of proportionality for 3 converters is controlled to regulate the DC output voltage. A control circuit provides immunity to AC input distortion and noise. The control circuit operates with various forward converter topologies, and is compatible with integrated circuit processes. A version using phase or symmetry modulated full-bridge converters, requires only 2 output rectifiers.

Three-phase AC power converter with power factor correction

A solid-state power converter using a transistor bridge structure and symmetry modulation to improve output stability when driving resonant loads. The power converter utilize a direct coupled driver for each upper switching transistor, permitting a wider control range than a transformer. In addition, various circuits to protect the load and the converter include: power limiting, surge reduction, thermal limiting, input over-voltage protection, output over-voltage shutdown, ground-fault shutdown, re-start delay, soft-start, and low-current off-on switch.

Tolerant power converter

A source power coupler for coupling a power source to a first transmission line and a second transmission line. DC power from the power source is conducted by the source power coupler to the first and the second transmission lines while AC signals on the first and the second transmission lines are isolated from the power source by the source power coupler. The source power coupler is comprised of an operational amplifier having a non-inverting input and an inverting input. The gate of a transistor is coupled to an output of the operational amplifier. The transistor's drain is coupled to one of the transmission lines. And the transistor's source is coupled to the inverting input of the op-amp. Thereby, a control loop is formed, which provides an AC impedance between the power source and one of the transmission lines. A resistor is coupled between the source of the transistor and the power source, and a capacitor is coupled between the non-inverting input of the op-amp and the power source. Another resistor is coupled between the non-inverting input of the op-amp one of the transmission lines. The capacitor and the second resistor provide a second control loop. This control loop provides a constant direct current voltage across the transistor.

Apparatus and method for providing AC isolation while supplying DC power

A transistorized source power coupler for coupling a power source to a pair of transmission lines. DC power from the power source is conducted by the transistorized source power coupler to the transmission lines. Meanwhile, AC signals on the transmission lines are isolated from the power source by the source power coupler. Consequently, the same pair of transmission lines can be used to supply power to cells of a communications system while also conducting data signals between those cells with minimal effect to the power source.

Source power coupler

A switching power supply includes an output transformer including a primary winding and a secondary winding. The primary winding is coupled to a switching transistor. Of importance, a diode is coupled across the switching transistor. During the time period before the switching transistor turns on, the output transformer draws magnetizing current through the diode, and thus before the transistor turns on, the voltage across the transistor is limited to one diode voltage drop. Thus, the switching losses incurred when the transistor turns on are minimized. In one embodiment, the power supply is a full bridge converter including first and second transistors coupled to one lead of the primary winding, and third and fourth transistors coupled to a second lead of the primary winding. The output voltage of the converter is regulated by regulator circuit which modulates the switching phase of the first and second transistors relative to the third and fourth transistors. The regulator circuit typically comprises a resonating LC circuit including an inductive element and a capacitive element. The on-time of the first and second switching transistors is dependent on the resonant frequency of the LC circuit. The on-time is modulated by varying the inductance of the inductive element in the LC circuit.

Power supply regulated by modulating the inductance in a resonant LC

A switching power supply includes an output transformer including a primary winding and a secondary winding. The primary winding is coupled to a switching transistor. Of importance, a diode is coupled across the switching transistor. During the time period before the switching transistor turns on, the output transformer draws magnetizing current through the diode, and thus before the transistor turns on, the voltage across the transistor is limited to one diode voltage drop. Thus, the switching losses incurred when the transistor turns on are minimized. In one embodiment, the power supply is a full bridge converter including first and second transistors coupled to one lead of the primary winding, and third and fourth transistors coupled to a second lead of the primary winding. The output voltage of the converter is regulated by modulating the switching phase of the first and second transistors relative to the third and fourth transistors.

Power supply with reduced switching losses

Each of a plurality of parallel connected power supplies is controlled by a parallel control circuit which measures the output current from each power supply and compares this output current to the average output current produced by all the power supplies and generates a signal representative of the difference therebetween to drive the output current of the power supply toward the average output curent from all power supplies. The structure includes in addition a switch for disconnecting the parallel control circuit of a failed power supply from the system and a booster resistor for assisting in bootstrapping the startup of a given power supply being inserted into parallel with the preexisting parallel connected power supplies.

Single wire current share paralleling of power supplies

A transformer for use in a power converter includes first and second primary windings tightly coupled to a first secondary winding, and third and fourth primary windings tightly coupled to a second secondary winding. Of importance, the first and second primary windings are only loosely coupled to the third and fourth primary windings. In one embodiment of the invention, the transformer includes a plurality of legs. The first and second primary windings and the first secondry winding are wound around one half of one of the legs but not a secnd half of the one leg. The third and fourth primary windings and the second secondary winding are wound around the second half of the one leg but not the first half. In another embodiment of the invention, the transformer includes a U core. The first and second primary windings and the first secondary winding are wound around a first leg of the U core while the third and fourth primary windings and the second secondary winding are wound around a second leg of the U core.

Proportional transistor base drive circuit for use in power converters

A control circuit is provided for controlling the on-time of a pair of switching transistors in a half bridge converter. The control circuit includes a first comparator for comparing the converter output voltage with a reference voltage. The control circuit also includes a circuit which generates a first signal indicative of the current through the primary winding of the converter output transformer. Also included is a circuit which generates a second signal indicative of the on-time of one of the switching transistors exceeding the on-time of the other switching transistor. The first and second signals are averaged and compared with the output voltage of the first comparator by a second comparator. The second comparator controls the on-time of the switching transistors. In this way, any imbalance in the on-time of the switching transistors is corrected by the control circuit.

Capacitor coupled current mode balance circuit

A power converter has a power switching stage which includes an output transformer containing a primary winding and a secondary winding, as well as structure for switching the current flowing through the primary from a first direction to a second direction. A feedback circuit is provided for feeding back a voltage proportional to a portion of the voltage across the primary winding on said output transformer to the structure for switching, to regeneratively turn on the switch and maintain the current flowing through the primary in the direction to which the current has been switched until the current is turned off. To help start the current through the primary in one direction or the other direction, structure is provided which supplies a pulse to the structure for switching, to positively start the current flowing in the desired direction through the primary. Because the power switching stage of a power converter uses primary and secondary windings, a novel structure is provided for the formation of these windings to insure their proper coupling.

A switching power supply for converting an input voltage to a different output voltage includes a power switch for producing a sequence of pulses from the input voltage, an output filter for filtering said pulses and for producing an output voltage from the filtered pulses, and means for sensing the output voltage and for controlling the value of the output voltage to a specified value. The power supply includes means for responding to a reduction in the input voltage beneath a normal value and for increasing the duty cycle of the sequence of pulses from the power switch in response thereto. Structure is provided for automatically controlling the frequency of the sequence of pulses to a selected value and for overriding the automatic control of this frequency so as to decrease this frequency in the event the load connected to the power supply draws too much current. Circuitry is provided to minimize off time in each period of the pulse sequence under 'brown-out' conditions.

Regulator control system

Each of a plurality of parallel connected power supplies is controlled by a parallel control circuit which measures the output current from each power supply and compares this output current to the average output current produced by all the power supplies and generates a signal representative of the difference therebetween to drive the output current of the power supply toward the average output current from all power supplies. The structure includes in addition a switch for disconnecting the parallel control circuit of a failed power supply from the system and a booster resistor for assisting in bootstrapping the startup of a given power supply being inserted into parallel with the preexisting parallel connected power supplies.

A power source provides continuous AC power by employing a bi-directional converter which interfaces a rechargable DC power storage device with AC mains power and AC loads. The bi-directional converter includes a transformer having first and second windings coupled in reverse polarity through dual switching means in parallel with one another. The switching means are coupled to a state controller responsive to conditions at the AC mains terminal, the AC load terminal and the DC power terminal. There are two general operating conditions, an active condition wherein DC power is provided to the AC load, and a standby condition wherein power is recovered by the DC storage device. In the standby condition, the converter operates in a so-called 'flyback' mode to recover power and to direct it to the DC storage device. In the active condition, the converter is pulse-width modulated according to a predetermined duty cycle to produce an AC sine wave output at the AC load terminals. Where the AC load includes reactive components, the converter operates to recover unused power from the load and to transfer power back to the DC power source whenever the polarity of the output voltage differs from the polarity of the output current.

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Cupertino, CA, United States of America

Kenneth T Small