As Input To Comparator Patents (Class 323/243)
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Patent number: 11947374Abstract: The present disclosure uses a capacitive voltage divider to supply a voltage that can be more readily handled by mainstream semiconductor and magnetic components (generally less than 1000 volts). The divided system voltage, expected to be between 500 and 1000 volts, is then converted to a power supply voltage to be used by the measuring equipment. For safety reasons, this voltage is frequently required to be less than approximately 50 volts if it is delivered via a connectorized cable with exposed contacts.Type: GrantFiled: February 4, 2020Date of Patent: April 2, 2024Assignee: Sentient Technology Holdings, LLCInventor: Dennis Allen Saxby
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Patent number: 9525361Abstract: A rectifying circuit includes a first diode coupled between a first terminal configured to receive application of an A.C. voltage and a first terminal configured to deliver a rectified voltage; and an anode-gate thyristor coupled between a second terminal configured to receive application of the A.C. voltage and a second terminal configured to deliver the rectified voltage, wherein an anode of the anode-gate thyristor is connected to the second terminal configured to deliver the rectified voltage.Type: GrantFiled: August 14, 2015Date of Patent: December 20, 2016Assignee: STMICROELECTRONICS (TOURS) SASInventor: Laurent Gonthier
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Patent number: 8698476Abstract: A control circuit and method for a current mode controlled power converter to convert an input voltage into an output voltage, dynamically adjust the peak or the valley of a ramp signal depending on either or both of the input voltage and the output voltage. Under different conditions of the input voltage and the output voltage, the current mode controlled power converter can generate stable output voltages with an invariant inductor and an invariant compensation circuit, without sub-harmonic which otherwise may happen.Type: GrantFiled: October 25, 2011Date of Patent: April 15, 2014Assignee: Richtek Technology Corp.Inventors: Wen-Wei Chen, Kuo-Chi Liu
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Patent number: 8605845Abstract: The present invention discloses an adaptive phase-shifted synchronization clock generation circuit and a method for generating phase-shifted synchronization clock. The adaptive phase-shifted synchronization clock generation circuit includes: a current source generating a current which flows through a node to generate a node voltage on the node; a reverse-proportional voltage generator coupled to the node for generating a voltage which is reverse-proportional to the node voltage; a ramp generator receiving a synchronization input signal and generating a ramp signal; a comparator comparing the reverse-proportional voltage to the ramp signal; and a pulse generator for generating a clock signal according to an output from the comparator.Type: GrantFiled: January 20, 2011Date of Patent: December 10, 2013Assignee: Richtek Technology CorporationInventors: Isaac Chen, An-Tung Chen
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Patent number: 8593841Abstract: A compensation circuit and method for constant current regulation of switching mode power supply are disclosed. The ringing waveform of a feedback signal, indicative of the output current of the power supply, causes error. To eliminate the error, a current source charges a capacitor in response to a demagnetizing oscillation signal indicative of the error caused by the ringing waveform of the feedback signal. The voltage across the capacitor is compared to a reference signal to generate a more accurate signal indicative of the conductive time of a secondary diode in a secondary winding of the switching mode power supply. This more accurate signal is inputted to a logic circuit to generate a constant current control signal to control a power switch of the power supply.Type: GrantFiled: November 4, 2011Date of Patent: November 26, 2013Assignee: Chengdu Monolithic Power Systems Co., Ltd.Inventors: Siran Wang, Yuancheng Ren, Junming Zhang, En Li
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Patent number: 8587265Abstract: A DC-DC converter control circuit includes: a slope signal generation circuit that generates a reference voltage by superimposing a slope voltage onto a standard voltage; a comparator that performs comparison of the reference voltage with an output voltage and generates a signal according to a result of the comparison; an oscillator that generates a pulse signal with a substantially constant cycle; and a control signal generation circuit that generates a control signal that turns on a switch based on a comparator output signal and turns off the switch based on the pulse signal.Type: GrantFiled: March 4, 2010Date of Patent: November 19, 2013Assignee: Spansion LLCInventors: Eiji Nishimori, Yoshihiko Matsuo, Osamu Takahashi, Takeshi Kimura
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Patent number: 8488342Abstract: System and method for regulating a power converter. The system includes a first signal generator configured to receive a first sensed signal and generate an output signal associated with demagnetization. The first sensed signal is related to a first winding coupled to a secondary winding for a power converter, and the secondary winding is associated with at least an output current for the power converter. Additionally, the system includes a ramping signal generator configured to receive the output signal and generate a ramping signal, and a first comparator configured to receive the ramping signal and a first threshold signal and generate a first comparison signal based on at least information associated with the ramping signal and the first threshold signal. Moreover, the system includes a second comparator configured to receive a second sensed signal and a second threshold signal and generate a second comparison signal.Type: GrantFiled: March 24, 2011Date of Patent: July 16, 2013Assignee: On-Bright Electronics (Shanghai) Co., Ltd.Inventors: Yunchao Zhang, Yaming Cao, Xiaomin Huang, Xiuhong Zhang, Lieyi Fang
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Patent number: 8410767Abstract: A DC-DC converter or the like capable of generating a stable output voltage is provided. A control circuit 11 of a current mode step-down DC-DC converter 1 includes a slope compensation circuit SC and an offset circuit IF1. The slope compensation circuit SC adds an increase gradient m2 due to slope compensation to an increase gradient of a coil current waveform Vsense in a range wherein an ON period Ton of a switch SW1 exceeds ½ of an operating cycle T. An offset circuit IF1 applies an offset voltage Voffset which becomes smaller depending on the ON period Ton in excess of ½ of an operating cycle T, to a coil current waveform Vsense.Type: GrantFiled: June 1, 2009Date of Patent: April 2, 2013Assignee: Fujitsu Semiconductor LimitedInventor: Toru Miyamae
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Patent number: 8076913Abstract: A voltage converter is provided. The voltage converter generates an output voltage signal and comprises a controller, a wave generator, a comparator, and a voltage converting unit. The controller generates a control voltage signal according to the output voltage signal and a first reference voltage. The wave generator generates a saw-wave signal and modifies at least one of an upper limit and a lower limit of a waveform of the saw-wave signal according to the output voltage signal. The comparator generates a pulse width modulation (PWM) signal according to the control voltage signal and the saw-wave signal. The voltage converting unit generates the output voltage signal according to the PWM signal.Type: GrantFiled: December 22, 2008Date of Patent: December 13, 2011Assignee: Mediatek Inc.Inventor: Chien Wei Kuan
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Patent number: 7923974Abstract: A power supply system includes multiple power converter phases. A controller (e.g., a processor device) monitors energy delivery for each of multiple power converter phases that supply energy to a load. The controller analyzes the energy delivery associated with each of the multiple power converter phases to identify an imbalance of energy delivered by the multiple power converter phases to the load. Based on the analyzing and detection of an imbalance condition, the controller modifies a future order of activating the multiple power converter phases for powering the load. Accordingly, a single phase of a multiphase switching power converter may be prevented from becoming overloaded while delivering energy to power the load.Type: GrantFiled: January 4, 2008Date of Patent: April 12, 2011Assignee: CHiL Semiconductor CorporationInventors: Gary D. Martin, Robert T. Carroll
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Patent number: 7760522Abstract: The present invention is intended to prevent the flow of a large input current into a DC/DC converter, to which power is fed from a power supply, before a supply voltage delivered from the power supply reaches a rated output voltage. A control unit included in the DC/DC converter includes a steady state detection block that detects a condition in which an input voltage to be applied to the DC/DC converter has been stabilized, and inhibits the power feed from the DC/DC converter until the input voltage delivered from a power supply in a preceding stage is stabilized.Type: GrantFiled: December 14, 2006Date of Patent: July 20, 2010Assignee: Fujitsu LimitedInventors: Taku Nobiki, Takahiro Miyazaki
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Patent number: 7711971Abstract: A system for monitoring multiple power supply signals with respect to a threshold has multiple inputs for receiving input power supply signals. A processing circuit of the system produces an output signal at a first level when the power supply signals have a prescribed relationship to a threshold value, and produces the output signal at a second level when at least one of the input power supply signals does not have the prescribed relationship to the threshold value. The processing circuit is configured for selecting the first level corresponding to a level of an input power supply signal at a pre-selected one of the inputs.Type: GrantFiled: June 28, 2006Date of Patent: May 4, 2010Assignee: Linear Technology CorporationInventor: Robert Peter Jurgilewicz
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Patent number: 7705570Abstract: A power supply trim control signal is produced by integrating differences between monitored and target values of the output voltage of a power supply. Register storage requirements are reduced by producing the target value from a nominal voltage value and one of a plurality of margin offsets selected in accordance with control data. The control data also selects between open and closed loop trim control. Stability is enhanced by changing the target value slowly in response to any change in the control data.Type: GrantFiled: January 26, 2009Date of Patent: April 27, 2010Assignee: Power Integrations, Inc.Inventors: David Alan Brown, Mircea Cristian Boros
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Patent number: 7694163Abstract: A system for generating and monitoring voltages on a variety of different components on a common printed circuit board. The system includes a programmable controller, a plurality of DC/DC converters for producing voltages for the devices and a plurality of voltage regulators for produced voltages for a plurality of CPUs on the board, such CPU voltages being produced in accordance with VIDs provided to the regulator by the CPU. The programmable controller: establishes a set point voltage for such one of the DC/DC converters; sequentially monitors the produced voltages produced, monitors voltages produced by the regulators for the CPUs by comparing the VIDs to the voltages produced by the regulators, and if during the sequencing any one of the converters is determined by the programmable controller as producing an improper voltage or if the any one of the regulators fails top produce the voltage indicated by the VIDs, disables the board.Type: GrantFiled: December 14, 2006Date of Patent: April 6, 2010Assignee: EMC CorporationInventor: David C. Bisbee
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Patent number: 7688009Abstract: In one embodiment, an LED current control circuit is configured with a sample and hold circuit that samples an error signal of an error amplifier during one time and holds the sampled value during a second time.Type: GrantFiled: June 29, 2006Date of Patent: March 30, 2010Assignee: Semiconductor Components Industries, LLCInventor: Abdesselam Bayadroun
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Patent number: 7671572Abstract: A voltage boost circuit and a method of boosting voltage using a voltage boost clock signal with varying frequency, in which the voltage boost circuit includes a boost voltage generator that responds to a voltage boost clock signal in order to boost an input voltage and outputs the boosted input voltage as an output boost voltage; and a boost voltage frequency control unit that responds to the result obtained by comparing a level of the output boost voltage and a level of a target boost voltage so as to change the boost voltage frequency of the voltage boost clock signal and outputs the voltage boost clock signal having the changed boost voltage frequency. The voltage boost circuit and the voltage boosting method can prevent a waste of the operating current during the boosting of the voltage.Type: GrantFiled: April 6, 2007Date of Patent: March 2, 2010Assignee: Samsung Electronics Co. Ltd.Inventor: Kyu-young Chung
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Patent number: 7638992Abstract: A drive power control device according to the present invention includes a transistor, which is input with a driving signal before current amplification into a base thereof, and which amplifies a current of the driving signal to drive an actuator; a switching element, which switches an input of a supply voltage to a collector of the transistor between on and off; and a voltage comparator, which compares a base voltage and a collector voltage of the transistor, and which controls the switching element such that the input of the supply voltage to the collector is turned off when a predetermined voltage difference occurs, and the input of the supply voltage to the collector is turned on when a predetermined voltage difference does not occur.Type: GrantFiled: January 24, 2007Date of Patent: December 29, 2009Assignee: Seiko Epson CorporationInventor: Yasuhiko Kosugi
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Patent number: 7397262Abstract: A burn-in system includes a testing stage configured to stress test one an integrated circuit and a power stage having a voltage control mode and a current control mode. The power stage is configured to supply power to the testing stage. One embodiment of the power stage includes a pulse width modulator, a current control circuit and a voltage control circuit. The pulse width modulator is configured to generate a modulated power output that is coupled to the testing stage. The current control circuit is configured to produce a current error output signal that is based on a difference between a measured load current, which is indicative of the current that is supplied to the testing stage by the modulated power output, and target load current.Type: GrantFiled: November 20, 2006Date of Patent: July 8, 2008Assignee: Micro Control CompanyInventors: Philip Alan Bailey, Kevin Roland Deters
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Patent number: 7382303Abstract: A power supply margin controller may alter the voltage of a control signal used to control the output voltage of a power supply. The controller may include a digital-to-analog converter having an input and an output, and a comparator having a first input coupled to receive the control signal, a second input coupled to the output of the digital-to-analog converter, and an output. The controller may include a processing system configured to deliver data to the input of the digital-to-analog converter based on the output from the comparator that causes signals at the inputs to the comparator to be substantially equal.Type: GrantFiled: September 20, 2006Date of Patent: June 3, 2008Assignee: Linear Technology CorporationInventors: Matthew J. Maloney, Andrew J. Gardner
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Patent number: 7339331Abstract: A dimmer circuit arrangement is disclosed including a second control circuit for controlling the operation of a triac for delivering current to a load, and a first control circuit for controlling the operation of an IGBT power semiconductor switch for controlling the rate of rise of load voltage. The first control circuit also controls the operation of the second control circuit.Type: GrantFiled: March 25, 2003Date of Patent: March 4, 2008Assignee: Clipsal Intergrated Systems Pty LtdInventor: James Robert Vanderzon
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Publication number: 20070236189Abstract: A voltage boost circuit and a method of boosting voltage using a voltage boost clock signal with varying frequency, in which the voltage boost circuit includes a boost voltage generator that responds to a voltage boost clock signal in order to boost an input voltage and outputs the boosted input voltage as an output a boost voltage; and a boost voltage frequency control unit that responds to the result obtained by comparing a level of the output boost voltage and a level of a target boost voltage so as to change the boost voltage frequency of the voltage boost clock signal and outputs the voltage boost clock signal having the changed boost voltage frequency. The voltage boost circuit and the voltage boosting method can prevent a waste of the operating current during the boosting of the voltage.Type: ApplicationFiled: April 6, 2007Publication date: October 11, 2007Inventor: Kyu-young Chung
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Patent number: 7259524Abstract: Apparatus and methods for regulating delivery of electrical energy to a lighting load are disclosed. An electrical waveform is received from a source of electrical energy. An integration value is generated based on a square of an amplitude of the received waveform. Electrical energy is delivered to the load until the integration value exceeds a threshold value. Thereafter, the delivery of electrical energy to the load is discontinued.Type: GrantFiled: June 10, 2004Date of Patent: August 21, 2007Assignee: Lutron Electronics Co., Inc.Inventors: Donald F. Hausman, Jr., Eric S. Lavin, Yang Boon Quek, Audwin Cash
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Patent number: 6111393Abstract: A phase-controlled voltage regulator of the series type, for supplying A.C. and D.C. electric loads in electronic ignition systems for internal-combustion engines. The A.C. and/or D.C. electric load is connectable in series with a single winding magneto generator via a respective electronic control switch; the voltage existing on the electric load is continuously detected and set to a supply voltage value required by the load by controlling the start time, and the time length of activation of the electronic control switch, during each half-wave of the generator voltage having a same polarity, in relation to the detected voltage on the electric load itself; no-load operating conditions for the magneto generator are maintained during the initial period of time for each half-wave, inhibiting the conduction of the electronic control switch.Type: GrantFiled: June 3, 1999Date of Patent: August 29, 2000Assignee: Ducati Energia S.p.A.Inventors: Gianni Regazzi, Pierluigi Calabri, Sergio Bianco
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Patent number: 5995391Abstract: A control arrangement for a multilevel convertor employs an AC reference signal which is locked to the AC system frequency and is compared with a number of DC threshold levels. Intersections of the reference signal and threshold levels triggers the firing and turning-off of GTOs within the convertor to produce the desired multilevel voltage output. Normal changes in system voltage, for example, are compensated by variation of the phase relationship of the reference signal with respect to the system voltage, and/or of the voltage values of the threshold levels. Sudden and drastic changes, especially reductions, in system voltage level are sensed and used to alter the amplitude of the reference signal so as to reduce the difference between the convertor multilevel voltage and the system voltage, thereby reducing the stress on the GTOs during faults.Type: GrantFiled: March 31, 1997Date of Patent: November 30, 1999Assignee: GEC Alsthom LimitedInventors: Mark Davies, Philip J Fitz, Keith Abbott
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Patent number: 5644214Abstract: A continuous current type power factor correction circuit in a power device having rectifying means for rectifying an alternating current, a booster converter having an inductor, a diode and a capacitor series connected to an output terminal of the rectifying means, a control switch connected in parallel with the series connection of the diode and capacitor, and a load connected across the capacitor for outputting a boosted direct current to the load according to switching operation of the control switch, and a power factor correction circuit controlling the switching operation of the control switch, the power factor correction circuit, comprising; an off-time controller comparing a first voltage signal with a second voltage signal and generating an off signal in response to the comparison, an on-time controller generating an on signal in accordance with a charge time period of the capacitor, the charge time period being determined from a point in time wherein the off-time controller generates the off signal,Type: GrantFiled: November 10, 1994Date of Patent: July 1, 1997Assignee: Samsung Electronics Co., Ltd.Inventor: Hoon-chul Lee
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Patent number: 5510679Abstract: Reverse phase-controlled dimming of an a.c.-powered load is accomplished by switching power to the load on and off during each half cycle. In one embodiment of the present invention, power is switched on when line voltage is substantially equal to load voltage and off at a selected time later in the half cycle or at any time that the voltage across the switch exceeds a predetermined value. Preferably, switching is accomplished with a pair of field effect transistors. The load preferably includes a capacitor from load hot to neutral. The present circuit permits quiet dimming of incandescent lamp loads without the need for complex circuitry. It is particularly well adapted for dimming low voltage lamps using a converter solid state transformer.Type: GrantFiled: April 25, 1991Date of Patent: April 23, 1996Assignee: Nutron Electronics Co., IncInventors: Nicholas F. Maiale, Jr., Donald F. Hausman
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Patent number: 5268631Abstract: An improved phase-controlled power control apparatus includes a semiconductor switching element for varying the effective power delivered to a load from the power lines. The conduction angle of the semiconductor power switch element is varied from a nominal angle to compensate for changes in power line voltage and for changes in load current. The amount of load current flow is continuously compared to the power line voltage to detect any overcurrent condition, even very close to the zero-crossing of the power line voltage. The shape of the transition from load current on to load current off (or vice versa) in controlled to minimize audible noise from the load. The load current can be shared between a plurality of compatible power control sections.Type: GrantFiled: November 6, 1991Date of Patent: December 7, 1993Assignee: Chicago Stage Equipment Co.Inventors: John E. Gorman, Rufus W. Warren
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Patent number: 5038081Abstract: Reverse phase-controlled dimming of an a.c.-powered load is accomplished by switching power to the load on and off during each half cycle. In one embodiment of the present invention, power is switched on when line voltage is substantially equal to load voltage and off at a selected time later in the half cycle or at any time that the voltage across the switch exceeds a predetermined value. Preferably, switching is accomplished with a pair of field effect transistors. The load preferably includes a capacitor from load hot to neutral. The present circuit permits quiet dimming of incandescent lamp loads without the need for complex circuitry. It is particularly well adapted for dimming low voltage lamps using a solid state transformer.Type: GrantFiled: December 16, 1987Date of Patent: August 6, 1991Assignee: Lutron Electronics Co., Inc.Inventors: Nicholas F. Maiale, Jr., Donald F. Hausman
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Patent number: 4968927Abstract: A device for regulating delivery of power from an AC voltage source to a load such as a lamp, a motor, a heating element or the like is described. Electronic circuitry responsive to the AC voltage generates a periodic signal whose magnitude indicates the instantaneous phase angle of the AC voltage relative to the most recent zero crossover of the AC voltage throughout the entirety of each half cycle of operation. A comparator generates a triggering signal when the phase angle signal corresponds to a threshold signal which may be manually set by adjustment of a voltage divider or which may be generated by a sensor in response to a predetermined condition, such as ambient light level or temperature, which is to be regulated by appropriate delivery of power to the load. The triggering signal is applied to a triac series connected with the load to initiate conduction of load current.Type: GrantFiled: August 25, 1988Date of Patent: November 6, 1990Assignee: Pelko Electric, Inc.Inventor: Kosta Pelonis
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Patent number: 4800330Abstract: A device for regulating delivery of power from an AC voltage source to a load such as a lamp, a motor, a heating element or the like is described. Electronic circuitry responsive to the AC voltage generates a periodic signal whose magnitude indicates the instantaneous phase angle of the AC voltage relative to the most recent zero crossover of the AC voltage throughout the entirety of each half cycle of operation. A comparator generates a triggering signal when the phase angle signal corresponds to a threshold signal which may be manually set by adjustment of a voltage divider or which may be generated by a sensor in response to a predetermined condition, such as ambient light level or temperature, which is to be regulated by appropriate delivery of power to the load. The triggering signal is applied to a triac series connected with the load to initiate conduction of load current.Type: GrantFiled: April 6, 1987Date of Patent: January 24, 1989Inventor: Kosta Pelonis
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Patent number: 4794507Abstract: A power controller includes a full-wave bridge rectifier circuit coupled to an A.C. line by a storage inductor with two windings and a saturating inductor. The output of the bridge rectifier is connected to a D.C. output terminal for producing output voltages for a symmetrical amplifier. The D.C. potential provided by the full-wave rectifier is compared with a ramp signal having an external ramp set point related to the D.C. output potential relative to a reference potential to provide a trigger pulse for controlling the time the SCR is gated on. A balancing system selectively switches auxiliary resistances in and out to maintain a desired balance. Upon sensing a gross imbalance, the SCR is turned off. The power controlling apparatus includes isolation circuitry for creating an isolation barrier having a high frequency path and a low frequency path. The high frequency path includes a transformer having main primary and secondary windings.Type: GrantFiled: December 14, 1987Date of Patent: December 27, 1988Assignee: Doble Engineering CompanyInventor: George A. Cavigelli
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Patent number: 4779038Abstract: An electric continuous-flow water heater generates a basic power with heating resistors in heating passages and a controllable power with three heating resistors in heating passages. The controllable power is controlled by a control system through a triac. At low flow rates two phases and a low controllable basic power is connected to the heating resistors. At high flow rates the heating resistors are star-connected and the controllable heating-resistors are delta-connected. An electric power output stage comprises a mains rectifier bridge, a Schmitt-trigger connected to the output thereof and a frequency divider with two outputs.The signals at the outputs are set by an edge of each third pulse and are reset by the corresponding edge of the following or next but one pulse. A semiconductor relay is optionally by the signals at the outputs through a selector switch or a logic circuit and is rendered conductive for one, two or three half waves.Type: GrantFiled: March 14, 1986Date of Patent: October 18, 1988Assignee: Erika EckerfeldInventor: Alfred Eckerfeld
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Patent number: 4766363Abstract: Power from an AC source is applied to a load under control of a power switching triac in response to signals from a feedback loop isolated from line voltage transients by means of a pair of opto-coupling devices respectively connecting the feedback loop to a load voltage sensor and the control electrode of the triac.Type: GrantFiled: May 29, 1987Date of Patent: August 23, 1988Assignee: Devore Aviation CorporationInventors: Robert E. Rutter, Robert M. Jensen
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Patent number: 4703197Abstract: The application of a controlled amount of alternating current (AC) power to an electrical load is achieved in a power switching circuit utilizing phase-control. In the switching circuit, a first analog signal is generated and repeats in every half-cycle of the AC power voltage waveform. A second analog signal is generated and is changeable in value either in a predetermined manner, or in response to the control input signal. The second signal is not synchronized with the half-cycles of the power source. A comparator detects when the first signal intersects the second signal in value and thereupon initiates gating of a switching device, such as a silicon-controlled rectifier.Type: GrantFiled: May 28, 1986Date of Patent: October 27, 1987Assignee: International Rectifier CorporationInventor: Kenneth H. Fleischer
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Patent number: 4695784Abstract: A battery charging circuit includes a silicon controlled rectifier full wave bridge that has its input connected across a conventional 60 hertz alternating current power line. The output of the bridge provides 120 hertz pulsating direct current to the battery being charged. The duration of each direct current charging pulse is determined by phase triggering of the silicon controlled rectifiers in the bridge. The silicon controlled rectifiers are triggered at a predetermined, identical firing angles by a conventional unijunction transistor relaxation oscillator which in turn is regulated by an output voltage and output current sensing circuit that established the noted firing angles so as to regulate, and limit at desirable upper valves, the charging voltage and current applied to the battery.Type: GrantFiled: September 4, 1986Date of Patent: September 22, 1987Inventor: William R. Reynolds
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Patent number: 4689548Abstract: A phase controlled regulator for selectively connecting a load to an AC source voltage such that substantially constant power is delivered to the load despite fluctuations in the magnitude of the source voltage is comprised of a circuit for detecting the zero crossings of the AC source voltage. A circuit produces a reference signal representative of a periodically increasing value in response to the zero crossings of the AC source voltage. A sensor produces a first signal representative of the instantaneous value of the AC source voltage. A comparator compares the reference signal with the first signal and produces an output signal when a predetermined relationship exists therebetween. A switch is responsive to the output signal for selectively connecting the load to the AC source voltage.Type: GrantFiled: April 14, 1986Date of Patent: August 25, 1987Assignee: American Sterilizer CompanyInventor: Douglas M. Mechlenburg
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Patent number: 4672301Abstract: What is proposed is an electronic circuit for controlling the amount of AC power delivered to an inductive or resistive load which continuously measures the actual phase lag between the load current and applied voltage and automatically adjusts the firing angle to provide the desired amount of AC power. The circuit includes an auxiliary on/off input with soft start and independently adjustable time delays for the on and off functions and also incorporates an input for remote power level control and features a half-wave rectified mode which delivers pulsating DC power to the load.Type: GrantFiled: April 4, 1986Date of Patent: June 9, 1987Assignee: Industrial Power Controls Inc.Inventors: Raymond T. Westfall, John F. Kohls
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Patent number: 4596947Abstract: A power control circuit in which a direct current voltage (Vp) proportional to the a.c. power applied to a load (L) is derived from voltages (Vc and Vv) proportional to the a.c. current flowing in the load (L) and the a.c. voltage across the load, respectively, and compared with a voltage (Vnp) representing nominal power to the load to provide a d.c. signal (Vd) the amplitude of which is utilized in conjunction with a staircase or ramp generator (SG) to add or deduct cycles of the a.c. power to or from the load circuit according to a predetermined load power rating and in dependence upon variations in the a.c. supply voltage to the load and changes in resistance of the load.Type: GrantFiled: September 19, 1983Date of Patent: June 24, 1986Assignee: Plessey Overseas Ltd.Inventors: John M. Alder, Robert S. Ireland
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Patent number: 4593232Abstract: An apparatus for use with an electrical lamp to control the electrical energy from a source of electrical power to the lamp to simulate the emission of a flame, the apparatus including an intensity controller section having first and second manually adjustable signal generating devices, the first being settable to the desired average brightness of the lamp, and the second being settable to a desired "flicker intensity". The flicker is effected by means of circuitry effectively providing a modulation about the value of the first signal. The magnitude of "flickering" may be reduced to zero permitting un-modulated full range light dimming control. A phase-angle controllable switching device in circuit relation with the lamp is actuated by a gate circuit within the circuitry. One or more lamps may be employed.Type: GrantFiled: January 20, 1984Date of Patent: June 3, 1986Inventor: Timothy K. McEdwards
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Patent number: 4580080Abstract: A phase control ballast in which a reactor and a triac are connected in series with an hid discharge lamp across an ac voltage source. A supra-linear converter connected to a rectifier-filter provides a reference voltage which is a supra-linear function of the source voltage. A ramp generator provides a ramp voltage climbing at a constant rate. At the instant when the ramp voltage exceeds the level of the reference voltage, a comparator circuit provides a signal to the gate of the triac which turns it on. A triac state detector responds to the turning on of the triac in either polarity by dropping the ramp voltage to zero and holding it at zero until the triac turns itself off.Type: GrantFiled: October 20, 1983Date of Patent: April 1, 1986Assignee: General Electric CompanyInventor: Alan M. Smith
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Patent number: 4580088Abstract: A soft-starting phase-control circuit for controlling both the cold in-rush and normal operating flows of current through a load from an A.C. source. The load may be resistive, may have a non-zero resistance temperature coefficient and may require a load voltage thereacross lower than the voltage provided by the A.C. source connected to the load and the control circuit. The control circuit utilizes at least one power switching device for selectively enabling and disabling the connection between source and load responsive to turn-on and turn-off states of a control signal provided at the output of a gate subcircuit.Type: GrantFiled: February 29, 1984Date of Patent: April 1, 1986Assignee: General Electric CompanyInventor: Milton D. Bloomer
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Patent number: 4524264Abstract: A temperature control apparatus detects an actual temperature of an object (e.g., sensor) to be controlled, and compares the actual temperature with a preset target temperature to obtain a difference therebetween, thereby keeping a heater temperature constant. The temperature control apparatus has a temperature rise rate limiter for controlling a temperature rise rate of the object to be controlled so as not to exceed a predetermined temperature rise rate. The object may thus not be damaged by thermal strain which results from a high temperature rise rate.Type: GrantFiled: May 11, 1983Date of Patent: June 18, 1985Assignee: Kabushiki Kaisha Toyota Chuo KenkyushoInventors: Takashi Takeuchi, Hideaki Takahashi, Haruyoshi Kondo
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Patent number: 4511836Abstract: The power drawn by a load (R.sub.L) from an A.C. network is controlled by an operational amplifier (OP1) and a power transistor (TR2). The operational amplifier makes the transistor leading when the voltage of its inverting input which is derived from said network, is lower than a reference voltage supplied to its non-inverting input. The pulses through the load take a form corresponding to the first and last parts of a sinusoidal half-wave. Their time lengths are shortened according as the voltage of the feeding network increases, and vice versa. FIG. 1.Type: GrantFiled: June 9, 1983Date of Patent: April 16, 1985Inventor: Bror A. Eriksson
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Patent number: 4495405Abstract: Automatic control system for controlling the switching point of a device which operates in at least two modes of operation, provides for automatic modification of the error signal which controls the switching action of the device by processing in real time the error signal to generate a resultant signal representative of the variation of the error signal over a time period, and then employing the resultant signal to modify the effect of the reference signal from which the error signal is derived. The control system can be employed in a chemical analysis instrument to control the on-off operation of a heater which supplies heated air to incubate samples.Type: GrantFiled: September 23, 1982Date of Patent: January 22, 1985Assignee: Coulter Electronics, Inc.Inventor: John E. Foster
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Patent number: 4426614Abstract: A trigger control circuit is provided for producing firing pulses for the thyristor of thyristor control system such as a power factor controller. The control circuit overcomes thyristor triggering problems involved with the current lag associated with controlling inductive loads and utilizes a phase difference signal, already present in the power factor controller, in deriving a signal for inhibiting generation of a firing pulse until no load current is flowing from the preceding half cycle and thereby ensuring that the thyristor is triggered on during each half cycle.Type: GrantFiled: November 30, 1981Date of Patent: January 17, 1984Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventor: Frank J. Nola
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Patent number: 4396818Abstract: An induction heating apparatus including a thyristor adapted to receive power from a power source, a gating control circuit for generating gating pulses for application to the gating control terminal of the thyristor, a commutating circuit which commutates off the thyristor, and a differentiator connected across the anode and cathode terminals of the thyristor to detect the power consumption of an inductively heated cooking ware. The gating control circuit comprises a gating pulse generator and a smoothing circuit for filtering the signal from the differentiator into a d-c signal which is compared with a reference level to detect the deviation of the power consumption from the reference value. The gating pulse generator is responsive to a potential at the anode of the thyristor to initiate timing action to determine the interpulse period or turn-off time of the thyristor and also responsive to the deviation of power consumption to vary the interpulse period.Type: GrantFiled: June 15, 1981Date of Patent: August 2, 1983Assignee: Matsushita Electric Industrial Co.Inventors: Hideyuki Kominami, Yoshio Ogino, Takumi Mizukawa, Takao Kobayashi
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Patent number: 4379254Abstract: An intensity control for fluorescent lamps of the type wherein a triac in series with the lamp provides control of the lamp current. Triac gating is controlled by a novel phase-lock circuit. In the phase-lock circuit, voltage squaring means are provided for producing unipolar square waves having a pulse width equal to a corresponding half cycle of the a.c. input power. Ramp waves generated from the square waves are applied to the base of a PNP transistor. Current through the lamp is sampled and produces a proportional voltage signal which is superimposed on a parallel path of the square waves to create a phase reference signal. An intensity control potentiometer supplies a selectable d.c. intensity control signal of polarity opposite the phase reference signal, and the intensity control signal and phase reference signal are algebraically added together. The resultant signals apply to the inverting input of integrating amplifier which reverses the polarity and integrates the resultant signal.Type: GrantFiled: March 23, 1981Date of Patent: April 5, 1983Assignee: Andrew L. D'OrioInventor: Frederick L. Hurban
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Patent number: 4376968Abstract: When a-c power line voltage is rectified by a phase-controlled SCR rectifier bridge to develop an adjustable d-c bus voltage which is then converted by an inverter back to a-c for driving a load, such as a motor, line voltage disturbances, resulting from momentary power outages or major power reductions, will have a deleterious effect on the operation of the inverter system. Such disturbances will cause improper firing of the SCR's and the d-c bus voltage may increase considerably, disrupting the normal operation of the inverter system and possibly destroying the switching devices in the inverter. Immunization against the effects of the line voltage disturbances is obtained by shutting down or disabling the phase-controlled SCR rectifier bridge anytime such a disturbance occurs.Type: GrantFiled: February 13, 1981Date of Patent: March 15, 1983Assignee: Borg-Warner CorporationInventors: Russel P. Wueschinski, Edward C. Siemon
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Patent number: 4360783Abstract: An effective voltage across a load such a lamp (L) is squared by means of a field effect transistor (FET) to produce an output voltage which varies in proportion to the power through the load (L). A trigger phase of a thyristor (TRC) connected between an A.C. power source (PS) and the load (L) is automatically varied in such a manner that the output voltage and thereby the power through the lamp (L) are regulated to a desired value.Type: GrantFiled: November 24, 1980Date of Patent: November 23, 1982Assignee: Ricoh Company, Ltd.Inventors: Kiyoto Nagasawa, Yuzi Narumi
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Patent number: RE33184Abstract: What is proposed is an electronic circuit for controlling the amount of AC power delivered to an inductive or resistive load which continuously measures the actual phase lag between the load current and applied voltage and automatically adjusts the firing angle to provide the desired amount of AC power. The circuit includes an auxiliary on/off input with soft start and independently adjustable time delays for the on and off functions and also incorporates an input for remote power level control and features a half-wave rectified mode which delivers pulsating DC power to the load.Type: GrantFiled: January 28, 1988Date of Patent: March 20, 1990Assignee: Industrial Power Controls, Inc.Inventors: Raymond T. Westfall, John F. Kohls