Including D.c.-a.c.-d.c. Converter Patents (Class 363/15)
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Patent number: 6515430Abstract: The invention relates to a power supply for an illumination system used to expose photo-initiated adhesives. The illumination system includes an arc lamp to provide light. As the lamp ages, its electrodes deteriorate, reducing the amount of light directed into a light guide and ultimately onto the adhesive. The power supply provides an increasing power input to the lamp to increase the light output of the lamp, countering this deterioration at least in part. The voltage and current drawn by the lamp are measured and a skewed control signal which magnifies the level is used to control the power input to the lamp.Type: GrantFiled: February 1, 2001Date of Patent: February 4, 2003Assignee: EXFO Photonic Solutions Inc.Inventor: Roy Kayser
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Publication number: 20030021125Abstract: A power supply comprising a DC-DC converter which comprisesType: ApplicationFiled: June 27, 2002Publication date: January 30, 2003Inventors: Alfred-Christophe Rufer, Claudio Zimmermann, Frederic Muller, Albert Bulliard
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Patent number: 6501194Abstract: An energy recovery snubber circuit for a bidirectional power converter, a method of operation thereof and a power plant employing the bidirectional power converter. The bidirectional power converter has first and second inputs, an inductor coupled to the first input and a power switch coupled between the inductor and the second input. In one embodiment, the energy recovery snubber circuit includes: (1) a clamping capacitor coupled to the second input; (2) a clamping diode coupled between the clamping capacitor and the first input; and (3) a snubber inductor coupled to a node between the clamping capacitor and the clamping diode.Type: GrantFiled: August 31, 2000Date of Patent: December 31, 2002Assignee: Lucent Technologies Inc.Inventors: Yimin Jiang, Hengchun Mao
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Publication number: 20020191417Abstract: An engine-driven portable generator using an inverter may still generate a voltage at its output terminals even though the engine is stopped. In view of this problem, the invention is to provide a portable generator, which is intended to prevent any residual voltage from generating between the output terminals. That is, a portable generator rectifying once an AC voltage into a DC voltage, converting the DC voltage into a single-phase AC voltage, and outputting the single-phase AC voltage, which has an output-stop-control unit (443) that, when an operating switch (305) is turned off, stops the operation of the inverter circuit at the timing when the voltage between the output terminals drops to 0, is provided.Type: ApplicationFiled: June 12, 2002Publication date: December 19, 2002Inventors: Kouji Suzuki, Takeshi Shinohara, Jun Takahashi
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Publication number: 20020171495Abstract: Two oscillators, such as in two pulse width modulator circuits of DC to DC power converters, are maintained in synchronization and at a predetermined phase shift from one another by a circuit incorporating a comparator. A sawtooth signal output from the master oscillator is fed to one comparator input while the sawtooth signal is filtered and applied to the second input of the comparator to generate an approximately 180° phase shift turn-on at the output of the comparator that is fed through a driver circuit to an input of a second oscillator. By insuring that the faster operating oscillator is the master, the slave oscillator will be triggered by the signal from the master.Type: ApplicationFiled: May 17, 2001Publication date: November 21, 2002Applicant: Texas Instruments IncorporatedInventor: Billy Joe Hughes
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Publication number: 20020154518Abstract: The invention describes a system for electrical transmission in the field of garments and a corresponding transmitter for this. Electrical circuits in garments are coupled, preferably inductively in a wireless manner with electrical devices and/or electrical circuits in other garments, wherein electrical energy is transmitted via the coupling. Energy transmission in both directions is preferably possible, wherein a distributed system results with sources and devices that can be coupled with each other. The efficiency of the inductive energy transmission is increased by regulation of the frequency, preferably using resonance. In addition, means for information transmission are proposed.Type: ApplicationFiled: April 18, 2002Publication date: October 24, 2002Inventors: Reinhold Elferich, Georg Sauerlaender, Thomas Duerbaum
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Patent number: 6456106Abstract: A method and circuit for detecting primary switch (12) status in isolated DC/DC converters by observing the falling speed of the voltage level at the sensing point (node Z) is disclosed. It is noted that high impedance oscillation has a relatively slow falling or rising time when compared to a valid signal. By observing the falling or rising time of a given signal during the appropriate time period, a determination can be made to differentiate a valid signal and an oscillating signal. More specifically, two reference voltages (A & B) are provided to compare against node Z voltage to generate a sense pulse. A reference pulse having a predefined duration is compared to the sense pulse. If the duration of the sense pulse is greater than the duration of the reference pulse, a latch is used to generate a low output signal. If the duration of the sense pulse is less than the duration of the reference pulse, a high output signal is generated.Type: GrantFiled: June 7, 2000Date of Patent: September 24, 2002Assignee: SRMOS, Inc.Inventor: Hsian-Pei Yee
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Publication number: 20020089861Abstract: A self-oscillation DC-DC converter circuit which includes a first transistor electrically connected to an input positive terminal, a second transistor electrically connected to the first transistor and operable to pass a portion of a base current of the first transistor, and a circuit to steady the output voltage electrically connected between the second transistor and an output positive terminal. The output negative terminal is connected directly to the input negative terminal. The self-oscillation DC-DC converter circuit does not use an auxiliary turn, thereby allowing the use of NPN transistors. Positive feedback is achieved by a voltage change Vce1 of the first transistor from a saturation state to a non-saturation state. In the non-saturation state, the second transistor is turned on, the first transistor is turned off and self-oscillation is achieved. With this construction, the self-oscillation DC-DC converter operates normally when the input voltage is lower than 5Vdc.Type: ApplicationFiled: August 16, 2001Publication date: July 11, 2002Inventors: Minchao Huang, Yi Chen
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Patent number: 6418037Abstract: A power supply for a computer is disclosed. The power supply is capable of providing power in both a DC domain and a high frequency AC domain. A first power consuming component can be coupled to the power supply to receive power in the DC domain, and a second power consuming component can be coupled to the power supply to receive power in the high frequency AC domain.Type: GrantFiled: August 16, 2000Date of Patent: July 9, 2002Assignee: Intel CorporationInventor: Michael T. Zhang
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Publication number: 20020071290Abstract: A power supply for both alternating current (AC) and direct current (DC) which has an AC/DC converter and DC/DC converter detachably coupled with each other. The AC/DC converter is adapted to convert an AC input voltage into a DC signal, and the DC/DC converter is adapted to convert a DC input voltage into a DC signal. An output voltage selector is provided to obtain a DC output voltage appropriate to an associated device. The present power supply can be conveniently carried, supply power to an associated device regardless of AC and DC input voltages and select a level of an output DC voltage. Therefore, the present power supply can be used universally irrespective of the types of associated devices and manufacturers.Type: ApplicationFiled: August 21, 2001Publication date: June 13, 2002Inventors: Dae-Young Youn, Hun-June Kim
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Patent number: 6385056Abstract: This instantaneously interruptible power source (I2PS) produces a precise AC output voltage. The I2PS can be built using only 7 power components, including an output capacitor. Moreover, currents applied thereto are unidirectional and independently developed. In the conventional switching power amplifier or uninterruptible power source, an output inductor continuously delivers a current to an output capacitor. A precise correction is simply impossible since, at the end of every switching cycle, the correction is either insufficient or continues while no longer required. This includes even most sophisticated class-D amplifiers. By contrast, the I2PS can instantaneously interrupt the correction and become idle. Without transformation, the output voltage can exceed supply voltages. An inductive block comprises at least one inductor and/or transformer for providing a return voltage. A switch or switches selectively apply a DC supply voltage or voltages to the inductive block.Type: GrantFiled: September 29, 2000Date of Patent: May 7, 2002Inventor: Jeff Gucyski
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Patent number: 6381150Abstract: The present invention comprises an isolated dual power supply having an internal feedback loop. The dual power supply comprises a modulated switched power converter generating an internal regulated voltage output coupled to an alternating current tank. The alternating current tank has a first and a second power switch that are alternately switched ON at a 50% duty cycle. When the first switch is ON, the internal regulated voltage output is coupled to a storage capacitor and a primary winding of a transformer in the alternating current tank wherein the storage capacitor is charged and a current flows in a first direction through the primary winding. Alternatively, when the second switch is ON, the charged storage capacitor discharges and a current flows in a second direction opposite to the first direction through the primary winding. In this fashion, the transformer becomes a linear device, allowing the use of internal feedback to control the external output of the transformer.Type: GrantFiled: November 19, 1999Date of Patent: April 30, 2002Assignee: IWATTInventor: Mark D. Telefus
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Publication number: 20020044458Abstract: An apparatus for and method of achieving current balancing among phases of a multi-phase power supply by reducing and controlling the temperature variation among packages disposed within each phase. Each package contains a dc-to-dc converter (e.g. a buck converter), a temperature sensor and may also contain a driver, which supplies a pulse train for driving the converter. By controlling the temperature among phases to within ±X % a balancing of currents among phases to within ±X/2% is achieved.Type: ApplicationFiled: August 6, 2001Publication date: April 18, 2002Inventor: Alan Elbanhawy
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Patent number: 6370039Abstract: The present invention comprises an isolated dual power supply having an internal feedback loop. The dual power supply comprises power converter responsive to an error signal for generating a DC internal regulated output voltage coupled to a DC/AC switching power converter having a transformer. The primary winding of the transformer is coupled to the DC internal output voltage and to one or more power switches. A control circuit drives the one or more power switches such that an alternating current having substantially a constant duty cycle flows through the primary winding. An error amplifier produces a control signal proportional to the difference of an output voltage at a load coupled to the secondary winding and a reference voltage equal to the maximum expected voltage losses at the load. The error signal is formed from a combination of the control signal and a signal proportional to the internal voltage output.Type: GrantFiled: March 31, 2000Date of Patent: April 9, 2002Assignee: IWattInventor: Mark D. Telefus
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Publication number: 20020018351Abstract: The invention relates to a device (2) which can be supplied with a given DC voltage (V1) and with a current of limited strength via a supply line (5). According to the invention, a capacitor (3) is connected to an input (15) of the device (2).Type: ApplicationFiled: July 2, 2001Publication date: February 14, 2002Inventor: Rudy Vanherck
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Publication number: 20020015315Abstract: The present invention comprises an isolated dual power supply having an internal feedback loop. The dual power supply comprises a modulated switched power converter generating an internal regulated voltage output coupled to an alternating current tank. The alternating current tank has a first and a second power switch that are alternately switched ON at a 50% duty cycle. When the first switch is ON, the internal regulated voltage output is coupled to a storage capacitor and a primary winding of a transformer in the alternating current tank wherein the storage capacitor is charged and a current flows in a first direction through the primary winding. Alternatively, when the second switch is ON, the charged storage capacitor discharges and a current flows in a second direction opposite to the first direction through the primary winding. In this fashion, the transformer becomes a linear device, allowing the use of internal feedback to control the external output of the transformer.Type: ApplicationFiled: November 19, 1999Publication date: February 7, 2002Inventor: MARK D. TELEFUS
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Publication number: 20020003712Abstract: An AC controller which provides programmable switching of AC power flow, together with producing a source of DC power for operating the AC controller. The AC controller is connected in series with only one side of the AC power source and the AC load. The AC controller utilizes a thyristor for AC power control switching. During the operation, the AC controller steals a small portion of each half-cycle of the AC power to provide DC power to the AC controller. The AC controller enables the flow of AC current by providing a gate current pulse at any predetermined time during the half cycle. Once the thyristor is ON, the AC current flows through the thyristor until the AC cycle is at or near zero. To provide an OFF state, the AC controller does not provide a gate current pulse. The AC controller uses an microcontroller for the programmable capability.Type: ApplicationFiled: January 20, 2000Publication date: January 10, 2002Inventor: Richard A. Bishel
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Patent number: 6329589Abstract: A solar panel arrangement for capturing solar energy and supplying power for use in a building. Solar cells are embedded in a window pane and generate electrical direct current that is converted, by an electrical circuit permanently attached to the pane, to an oscillating current that is fed to a ferrite core mounted to the pane. An external ferrite core is mounted in close proximity to the core, so that the oscillating current can be picked up and supplied to a building. The arrangement allows window panes to be pre-formed or manufactured with certain built-in electrical components, and, without the need for skilled labor, to be easily connected to a power circuit external of the window pane.Type: GrantFiled: March 21, 2000Date of Patent: December 11, 2001Inventors: John Wing-Yan Tang, Tai-Yan Tang
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Patent number: 6294848Abstract: The present invention discloses a power distribution system for circuit boards connected to a backplane in a customer premises telecommunications hub. Each functional board in the system contains its own DC to DC converter for receiving a first DC supply voltage from the backplane and supplying a lower voltage to the circuits on the board. The converter is of the single ended primary inductance converter type having its inductance element positioned between the power switching device and the input power capacitor. The power converter is connected to the main power supply through two pins of a staged or staggered connector on the board. A resistor is connected between the earlier of the two pins to make contact with the main supply. Due to the small size of the input resistor required for the converter, the input capacitor can almost fully charge before the second pin, which connects directly to the converter input, makes contact.Type: GrantFiled: October 12, 2000Date of Patent: September 25, 2001Assignee: Sprint Communications Company, L.P.Inventor: Earl Goodrich, II
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Patent number: 6291764Abstract: The present invention prevents an increase in an overvoltage and increases an optimum operating voltage of a power inverter. A photovoltaic power generation device is provided with a solar cell device 1, a power inverter 2 for inverting output from the solar cell device 1 into AC power, a current path circuit 3 connected in parallel between the solar cell device 1 and the power inverter 2, and a current detection circuit 4 for detecting a current feeding back to the solar cell device 1. When a current detected by the current detection circuit 4 reaches beyond a predetermined current value, the current path circuit 3 is cut off.Type: GrantFiled: March 23, 2000Date of Patent: September 18, 2001Assignee: Sanyo Electronics Co., Ltd.Inventors: Takeo Ishida, Ryuzo Hagihara, Hitoshi Kishi
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Patent number: 6288912Abstract: A power supply device (201) for a light box (102) is provided for the backlighting of liquid crystal display screens. The device (201) includes a regulating DC/DC converter (204) of the booster type, powered directly by a 28-volt power supply so as to deliver directly a 50-volt stabilized DC voltage for powering the light box (102). The converter (204) includes an output diode (208) which protects the device. An energy reserve is obtained via a capacitor (209) supplied directly with the 50-volt voltage. A second converter (111) with galvanic isolation provides a set of supply voltages to electronic control cards (103) of display screens illuminated by the light box (102). A link between the light box (102) and the control cards (103) is effected by a galvanic isolation device (210). The device (201) makes it possible to increase the efficiency of the power supply so as to decrease weight, volume and cost thereof.Type: GrantFiled: June 16, 2000Date of Patent: September 11, 2001Assignee: Thomson-CSF SextantInventor: Bernard Bedouet
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Publication number: 20010001051Abstract: An exemplary embodiment of the invention is a power system for providing power to a critical load. The system includes a first power source producing sufficient power to supply the critical load and a second power source, independent of said first power source. The second power source produces sufficient power to supply the critical load. The system also includes a rotary device having a first power input circuit and a second power input circuit. The second power source is coupled to the rotary device at the second power input circuit. A transfer switch selectively couples the first power source to the first power input circuit and the second power input circuit.Type: ApplicationFiled: January 3, 2001Publication date: May 10, 2001Inventor: William E. Cratty
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Patent number: 6208528Abstract: A blank formed from electrically conductive sheet material defines a continuous conductive path which includes two terminal ends and at least three loops disposed along the path. The blank is foldable at preselected folding locations on the path to position the loops in overlying relation to one another, and the blank is preferably formed with the loops disposed along the conductive path in substantially the same plane. The blank is used to form a multi-turn planar winding for a magnetic device such as, for example, an inductor or transformer which may be incorporated into electrical circuits such as power supplies. The planar magnetic device provides a low overall volume and profile, as well as a substantially higher volume or surface area of conductive material per turn of the winding compared to conventional wire or etched windings to provide a higher current carrying capacity and fewer turns compared to conventional windings.Type: GrantFiled: May 28, 1999Date of Patent: March 27, 2001Assignee: Nidec America CorporationInventors: Louis A. Soto, Paul W. Godek
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Patent number: 6153869Abstract: An AC/DC type microwave oven has a function of managing an input power source. The AC/DC type microwave oven comprises a rotatable inverter which inverts a DC power source to an AC power source by a rotational force, a high voltage transformer which receives a common power source or an AC power inverted by the rotatable inverter and outputs a higher voltage, a magnetron which is driven by the high voltage outputted from the high voltage transformer and radiates a microwave and a power control unit for sensing a signal from a power selecting key and preventing the AC and DC power sources from being simultaneously inputted. Therefore, both of AC power and DC power are prevented from being simultaneously supplied to the microwave oven which could result in a malfunction, or an overload occurs in the electric components of the microwave oven. Therefore, only one input power of the common and DC power sources is selected and, the microwave oven is operated properly.Type: GrantFiled: January 7, 1999Date of Patent: November 28, 2000Assignee: Samsung Electronics Co., Ltd.Inventors: Chul Kim, Yong-woon Han, Seong-deog Jang, Han-jun Sung
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Patent number: 6153870Abstract: Disclosed is an AC/DC type microwave oven. The AC/DC type microwave oven comprises a rotatable inverter which inverts a DC power source to an AC power source by means of a rotational force, a high voltage transformer which receives a common power source or an AC power inverted by the rotatable inverter and outputs a higher voltage and a magnetron which is driven by the high voltage outputted from the high voltage transformer and radiates a microwave, and further comprises a control unit which controls the operation of the rotatable inverter so as to output a stable frequency. The rotatable inverter comprises a motor, a commutator driven by the motor and a plurality of brushes, which are respectively contacted with an outer surface of the commutator.Type: GrantFiled: January 7, 1999Date of Patent: November 28, 2000Assignee: Samsung Electronics Co., Ltd.Inventors: Chul Kim, Yong-woon Han, Seong-deog Jang, Han-jun Sung
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Patent number: 6118351Abstract: The present invention provides a power micromagnetic integrated circuit having a ferromagnetic core, a method of manufacture therefor and a power processing circuit employing the same, that includes: (1) a substrate; (2) an insulator coupled to the substrate and (3) a metallic adhesive that forms a bond between the insulator and the ferromagnetic core to secure the ferromagnetic core to the substrate.Type: GrantFiled: June 10, 1997Date of Patent: September 12, 2000Assignee: Lucent Technologies Inc.Inventors: Dean P. Kossives, Ashraf W. Lotfi, Lynn F. Schneemeyer, Michael L. Steigerwald, R. Bruce Van Dover
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Patent number: 6101102Abstract: Frequency regulating apparatus comprising a high power, voltage variable dielectric varactor or capacitor (or ferroelectric voltage variable dielectric capacitor) for use as a control element in the regulation circuit that actively tunes a resonant network to modulate power delivered to a load. The voltage variable dielectric capacitor comprises a substrate having a bottom electrode 33 formed thereon. A dielectric material is disposed on the substrate is a crystallized ceramic material that preferably comprises a barium, strontium, and titanium mixture. A top electrode is disposed on top of the crystallized ceramic material. Methods of fabricating the voltage variable dielectric varactor (capacitor) are also disclosed.Type: GrantFiled: April 28, 1999Date of Patent: August 8, 2000Assignee: Raytheon CompanyInventors: Michael Brand, Thomas Kirk Dougherty, John J. Drab, Brian M. Pierce
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Patent number: 6081434Abstract: A switch circuit comprising a semiconductor switch and an inverse-parallel diode is connected between a main electricity storage unit 4 and a primary winding 142P of an insulating transformer 142 and a switch circuit including a semiconductor switch and a diode is connected in inverse-parallel between a secondary winding 142S of the insulating transformer 142 and an auxiliary electricity storage unit 10. The switch circuits are controlled on/off, whereby power is supplied from the main electricity storage unit 4 to the auxiliary electricity storage unit 10 or from the auxiliary electricity storage unit 10 to the main electricity storage unit 4 for charging the electricity storage unit 10 or 4.Type: GrantFiled: March 22, 1999Date of Patent: June 27, 2000Assignee: Fuji Electric Co., Ltd.Inventors: Shigenori Kinoshita, Kouichi Ueki, Yasuo Kobayashi
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Patent number: 6069799Abstract: A power converter having an input and output and a method of operating the power converter. In one embodiment, the power converter includes a power transformer having primary and secondary windings and a power switch coupled to the input and configured to impress an input voltage across the primary winding. The power converter further includes a hybridge synchronous rectifier coupled to the secondary winding and including first and second synchronous rectifier switches. The power converter still further includes a separate drive winding wound on the power transformer and coupled between the first and second synchronous rectifier switches. The separate drive winding is configured to alternately energize the first and second synchronous rectifier switches.Type: GrantFiled: May 4, 1998Date of Patent: May 30, 2000Assignee: Lucent Technologies Inc.Inventors: Wayne C. Bowman, Van A. Niemela, Allen F. Rozman
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Patent number: 6066926Abstract: An electronic flash device in which a voltage of a power supply battery is boosted to be supplied to a load, includes a first oscillation portion of self-excited type, a second oscillation portion of separately-excited type, and a changeover portion which performs a changeover between causing the first oscillation portion to operate and causing the second oscillation portion to operate, according to a condition of the load.Type: GrantFiled: October 10, 1997Date of Patent: May 23, 2000Assignee: Canon Kabushiki KaishaInventor: Masanori Yamada
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Patent number: 6034517Abstract: The present invention relates to circuits and methods for improving the efficiency of step down switching regulators converting a high input voltage to a low output voltage. Furthermore, the present invention relates to circuits and methods to achieve such efficiency improvements while maintaining controllability during light output load conditions. In a preferred embodiment, the current mode switching regulator circuit includes a logic section, an output switch section controlled by the logic section, an oscillator for providing periodic timing signals to the logic section to turn the output switch ON, a feedback amplifier for developing an integrated error signal based on the output voltage, and a current comparator including an output, the current comparator for comparing the integrated error signal to the instantaneous value of the current in the output switch, the output of the comparator producing a signal which causes the logic section to turn the output switch OFF.Type: GrantFiled: October 27, 1998Date of Patent: March 7, 2000Assignee: Linear Technology CorporationInventor: Jeffrey Schenkel
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Patent number: 6028373Abstract: A power supply system (300) provides a staged startup of multiple loads (303, 305). Preferably, the power supply (300) is a switching power supply that provides power, in the form of a primary output voltage to a first output terminal (319) and to a second output terminal (325). A first load (303) demands a first startup power from the switching power supply through the first output terminal (319). A voltage comparator (333) provides an enable signal (335) when a primary output signal, present at the first output terminal, exceeds a predetermined threshold (335). A load coupling device, preferably a gateable voltage regulator (331), is coupled to the second output terminal (325). The gateable voltage regulator (331) has an output (327) coupled to a second load (305).Type: GrantFiled: August 2, 1993Date of Patent: February 22, 2000Assignee: Motorola, Inc.Inventors: Sang Hoon Kim, Brian D. Chapman
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Patent number: 6021499Abstract: The present invention is a method and system for flexibly and efficiently providing electrical power within a computer system. The present invention comprises an isolated ground reference direct current power supply, including an AC/DC converter that transforms alternating current into direct current and an isolation component that provides DC voltage outputs. At least two of the DC voltage outputs have ground references that are isolated from one another in a manner that is compliant with IEEE 1394 requirements. One of the ground references is supplied as the chassis ground for the computer system and is coupled to most of the components of the computer system. Another of the ground references is isolated from the chassis ground reference and is coupled to the physical layer of an IEEE serial communications circuit. A DC to DC converter is used with the power supply to generate the isolated ground reference for the physical layer.Type: GrantFiled: March 31, 1998Date of Patent: February 1, 2000Assignees: Sony Corporation of Japan, Sony Electronics, Inc.Inventor: Rassoul Aleshi
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Patent number: 6008997Abstract: A series resonant circuit converts a DC input to an AC output. The circuit includes first and second series circuits connected across the DC input, but in opposite polarities. Each series circuit includes a switch, a transformer primary and a capacitor. Also within each series circuit, a diode is connected across the combination of the switch and transformer primary to provide limiting. The transformer primaries are connected together so that the switches are effectively in series. Singular and multiple transformer cores may be used in connection with singular and multiple secondaries to provide the AC output.Type: GrantFiled: March 22, 1999Date of Patent: December 28, 1999Assignee: Lambda Electronics IncorporatedInventor: Isaac Cohen
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Patent number: 5986384Abstract: A self-oscillation type signal converter includes a piezoelectric ceramic, four electrodes P.sub.A, P.sub.B, Q.sub.C and Q.sub.D, a load resistance R consisting of N parts R.sub.i (i=1, 2, . . . , N), N-1 terminals T.sub.i {i=1, 2, . . . , (N-1)} between two parts R.sub.i and R.sub.(i+1), two terminals T.sub.0 and T.sub.N, formed on the electrodes Q.sub.C and Q.sub.D, respectively, a switch, a vibration circuit connected between the electrodes P.sub.A and P.sub.B, and a rectification circuit connected between two of all the terminals T.sub.0, T.sub.i and T.sub.N, via the switch. The electrodes P.sub.A, P.sub.B, Q.sub.C and Q.sub.D are formed on four side surfaces A, B, C and D, of the piezoelectric ceramic, respectively. The load resistance R is connected between the terminals T.sub.0 and T.sub.N. The piezoelectric ceramic, the electrodes P.sub.A, P.sub.B, Q.sub.C and Q.sub.D, form a piezoelectric vibrator. When a high-frequency electric signal E.sub.IN with a voltage V.sub.IN is applied to the electrodes P.Type: GrantFiled: December 17, 1998Date of Patent: November 16, 1999Inventor: Kohji Toda
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Patent number: 5973936Abstract: The current-voltage regulator has a reference voltage source with an output. Two transconductance amplifiers each have two inputs and a current output. The current outputs of the transconductance amplifiers are coupled to one another and form an output of the current-voltage regulator. One of the inputs of the transconductance amplifiers is coupled to the output of the reference voltage source, and the other inputs of the transconductance amplifiers are driven, respectively, by a current sensor signal and a voltage sensor signal.Type: GrantFiled: December 17, 1998Date of Patent: October 26, 1999Assignee: Siemens AktiengesellschaftInventors: Michael Lenz, Frank-Lothar Schwertlein
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Patent number: 5949658Abstract: A multiple output dc to dc converter is described that improves efficiency for auxiliary outputs using a secondary side switch. The converter uses a switching circuit to place an alternating voltage from a dc power source across a transformer. The switching circuit is controlled by a primary PWM controller which regulates the primary output voltage by adjusting the duty cycle of the switching circuit. The switching circuit produces an alternating voltage across the center-tapped winding of the transformer, which is rectified by diodes connected to the winding to create a full-wave output. This output is used by a primary output circuit to create the primary output voltage, and is also used to create an auxiliary output voltage by using a secondary side switch and auxiliary PWM controller to regulate the auxiliary output.Type: GrantFiled: December 1, 1997Date of Patent: September 7, 1999Assignee: Lucent Technologies, Inc.Inventors: Vijayan Joseph Thottuvelil, Richard William Farrington
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Patent number: 5914842Abstract: In an electrical power supply system provided with a step-down distribution transformer connected to a power source to supply current to at least one neutral grounded load center, said power source having a conductor connected to a first primary grounding connection, said distribution transformer having a magnetic core, and a primary and a secondary winding independently mounted on said magnetic core, said secondary winding being electrically connected to a pair of output terminals and to a center-tapped neutral terminal, said terminals being connected to said load center, said primary winding being electrically connected to a pair of input terminals arranged for connection to said primary power source, one of said input terminals being further connected to a second primary grounding connection, said center-tapped neutral terminal being connected to said second primary grounding connection via a shunting conductor, an improvement comprising a current balancing transformer (CBT) having a magnetic core and a fiType: GrantFiled: September 26, 1997Date of Patent: June 22, 1999Assignee: SNC Manufacturing Co., Inc.Inventor: Carl J. Sievers
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Patent number: 5907479Abstract: A family of integrated filter forward converters includes a filter inductor is magnetically included in the transformer assembly. A basic circuit includes a DC voltage source, two cross-coupled capacitors, a clamp diode, a power switch, two identical transformers (or equivalent to a transformer and a filter inductor), two rectifying diodes, a filter capacitor and a load resistor. Several useful versions can be obtained by modifying the basic circuit for different applications. Both the input and output currents of the present invention can yield continuous current operation.Type: GrantFiled: December 17, 1997Date of Patent: May 25, 1999Inventor: Sam C. Leu
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Patent number: 5895983Abstract: A flash charging circuit has first and second transistors (TR1, TR2) which are connected to opposite terminals of a primary coil of a transformer, a battery is connected to a center tap provided in a middle portion of the primary coil, and first and second drive pulse signals (S1, S2) are applied to the first and second transistors to drive them alternately with each other, to induce an alternating secondary current in a secondary coil of the transformer. Each of the first and second drive pulse signals have a shorter pulse duration (Pd) than a pulse separation (Ps). The phases of the first and second drive pulse signals are determined such that both the first and second drive pulse signals take a low level for a time (Ta) before and after each drive pulse of the first and second drive pulse signals, so that both the first and second transistors are OFF immediately before either of them is turned ON.Type: GrantFiled: July 11, 1996Date of Patent: April 20, 1999Assignee: Fuji Photo Film Co., Ltd.Inventor: Katsumi Motomura
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Patent number: 5821826Abstract: An apparatus and method for generating signals. According to one embodiment, the apparatus has an oscillator generating a series of signals, an output stage for transforming the series of signals into a second series of signals, and a watchdog for providing a control signal to the output stage to hold the output stage in a selected state and for changing the control signal to enable the output stage in the selected state when the oscillator generates a first signal of the series of signals.Type: GrantFiled: June 17, 1996Date of Patent: October 13, 1998Assignee: Burr-Brown CorporationInventor: Trevor Newlin
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Patent number: 5787336Abstract: Disclosed is a method for operating a communications signal transmitter and apparatus for carrying out the method. The method includes the steps of receiving a communications signal; sensing a signal strength of the received communications signal, the signal strength being indicative of the current user demand; adjusting an output of a power supply that supplies operating power to a communications signal transmitter amplifier in accordance with the sensed signal strength so as to increase the output of the power supply when the sensed signal strength increases and to decrease the output of the power supply when the sensed signal strength decreases; and amplifying the received communications signal with the communications signal transmitter amplifier. The step of sensing may include a step of subtracting a noise component from the received communications signal.Type: GrantFiled: November 8, 1994Date of Patent: July 28, 1998Assignee: Space Systems/Loral, Inc.Inventors: Edward Hirschfield, Robert A. Wiedeman, Stanley Canter
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Patent number: 5768111Abstract: In a DC--DC converter comprising a piezoelectric transformer (25) having an input capacitance between a pair of transformer input teminals and a transformer resonant frequeney, an input switching stage (27) responsive to a DC input signal for supplying a sinusoidal transformer input signal, and an output rectifier stage (29) for producing a converter output voltage across a load resistor (23), the switching stage includes an input series inductor (39) connected in series to one of the transformer input terminals and having an input series inductance that defines a switching resonant frequency in cooperation with the input capacitance to be different from the transformer resonant frequency. It is preferred when the switching stage is operable in zero volt switching that the input series inductance be either between 1.0 and 2.2 .mu.H or between 3.0 and 3.4 .mu.H, or more preferably either between 1.4 and 1.8 .mu.H or about 3.0 .mu.H, if the input series inductance should be 2.8 .mu.Type: GrantFiled: February 26, 1996Date of Patent: June 16, 1998Assignee: NEC CorporationInventor: Toshiyuki Zaitsu
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Patent number: 5757624Abstract: A DC--DC converter unit includes a high-voltage circuit having a main fuse provided in a case, a branch circuit branched from the high-voltage circuit on a downstream side of the main fuse, a subfuse inserted in the branch circuit, and a DC-DC converter connected to a terminal of the branch circuit. A main battery, mounted on an electric vehicle, is connected to a primary side of the high-voltage circuit. A high-voltage load is connected to a secondary side of the high-voltage circuit. The circuit of the high-voltage portion can be shortened, so that covered harnesses and waterproof connectors used in the high-voltage portion can be reduced to thereby reduce the cost. Further, the reliability of the high-voltage portion can also be improved.Type: GrantFiled: December 20, 1996Date of Patent: May 26, 1998Assignee: Honda Giken Kogyo Kabushiki KaishaInventor: Kenji Kawaguchi
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Patent number: 5745350Abstract: In a power supply circuit supplying a high voltage charger of an implantable cardioverter-defibrillator (ICD), a changer circuit switches the power source of the power supply circuit between a battery and an output signal of a step-up converter. The signal derived from the boost winding rises to a high voltage when the high voltage charger charges the storage capacitors of the ICD. A system current measurement circuit can be provided in the power supply circuit.Type: GrantFiled: June 7, 1996Date of Patent: April 28, 1998Assignee: Pacesetter, Inc.Inventors: Stephen T. Archer, Kenneth J. Carroll
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Patent number: 5742470Abstract: A circuit arrangement including an EHT cascade circuit (1) with at least a series arrangement (2, 3) of capacitors having staggered conductive strips (19, 20, 21, 22, 23, 24, 25) provided on both sides of a dielectric layer (18, 18a, 18b) which, together with the conductive strips (19, 20, 21, 22, 23, 24, 25), is wound about a support to constitute a winding form (15, 15a, 15b). A compact and low-cost construction, particularly for use of the circuit arrangement in an EHT generator for a picture display tube, is achieved in that the EHT cascade circuit (1) precedes an EHT output capacitor (6, 12), and in that the EHT output capacitor (6, 12) is the support.Type: GrantFiled: June 25, 1996Date of Patent: April 21, 1998Assignee: U. S. Philips CorporationInventor: Hubert Raets
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Patent number: 5708357Abstract: A power supply circuit configuration for an electronic controller comprises a current transformer, a first rectification circuit, a voltage drop circuit, a second rectification circuit, a voltage regulator and filter circuit, a control unit and a power switch unit. The electronic controller is connected externally to a pair of power cords and to a load through a power switch unit. The load is connected in series to the primary winding of the current transformer. When the power switch unit is triggered by the controller and the load start operating, the current flowing in the load is equal to the current flow in the primary winding of the current transformer. Then, the DC current is supplied to the control unit from a first electric path consisting of the current transformer, the first rectification circuit and the voltage regulator and filter circuit.Type: GrantFiled: August 28, 1996Date of Patent: January 13, 1998Inventor: Jing-horng Chen
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Patent number: 5703770Abstract: A method and apparatus for generating a high voltage by converting input power at a low voltage to output power at a high voltage, by: supplying input power to a low voltage unit to produce a periodic signal having a frequency; supplying the periodic signal to a rectifier voltage multiplier of a specific type to cause the rectifier voltage multiplier to produce the output power at a high voltage, wherein the ratio of output power to input power is a function of the frequency of the periodic signal; identifying the type of the rectifier voltage multiplier; and continually adjusting the frequency of the periodic signal toward a value which maximizes the ratio of output power to input power.Type: GrantFiled: August 9, 1995Date of Patent: December 30, 1997Assignee: Sames S.A.Inventors: Jean Pierre Burtin, Flavien Dobrowolski, Caryl Thome
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Patent number: 5699236Abstract: A high-voltage stabilization circuit of a monitor can detect accurately a change of a high voltage of a secondary winding of a high-voltage transformer.Type: GrantFiled: May 30, 1996Date of Patent: December 16, 1997Assignee: Daewoo Electronics Co., Ltd.Inventor: Hyun-Chil Choi
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Patent number: RE37510Abstract: A power converter with a self synchronized synchronous rectifier includes one or two drive windings to provide positive drive to the control electrodes of the controlled switches (FETs) of a self synchronized synchronous rectifier. The polarities of these windings am selected so that the switched devices are driven appropriately to rectify the periodic signal output of the secondary winding of the power transformer of the converter. In some arrangements one or two drive windings are included as extra windings in the power transformer and connected to provide the proper polarity drive signals. The turn ratios of the drive windings to the other windings are selected to provide the proper gate drive signal levels. In an alternative arrangement a separate drive transformer may be provided to supply the gate drive signals.Type: GrantFiled: December 17, 1998Date of Patent: January 15, 2002Assignee: Lucent Technologies Inc.Inventors: Wayne C. Bowman, Van A. Niemela