Patents by Inventor David K. Lacombe
David K. Lacombe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8547033Abstract: A solid state lighting controller arranged for use with a single stage power factor correction switched mode power supply, a light emitting diode (LED) string and a current sense element arranged to sense current through the LED string, the solid state lighting controller constituted of: a current governor in series with the LED string exhibiting a governor differential amplifier and a governor electronically controlled switch responsive to the output of the governor differential amplifier, the current governor arranged to limit current flow through the LED string responsive to a current limit reference; and a feedback circuit exhibiting an error amplifier, the feedback circuit arranged to feedback a signal to the power factor correction switched mode power supply controller whose value is a function of the difference between the current through the LED string sensed by the current sense element and a target current signal.Type: GrantFiled: October 3, 2011Date of Patent: October 1, 2013Assignee: Microsemi Corp.—Analog Mixed Signal Group Ltd.Inventors: Yair Darshan, Chii-Fa Chiou, David K Lacombe
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Patent number: 8358082Abstract: An apparatus and method for igniting a lamp during a strike mode of an inverter comprising: sequentially controlling a duty cycle sweep and a frequency sweep of driving signals in the inverter to provide an increasing output voltage to the lamp. One embodiment advantageously includes a closed feedback loop to implement the duty cycle sweep and the frequency sweep such that an open lamp voltage is reliably regulated during the strike mode. For example, the closed feedback loop stops the duty cycle sweep or the frequency sweep when the output voltage to the lamp reaches a predetermined threshold and makes adjustments to the duty cycle or frequency the driving signals as needed to keep the output voltage at approximately the predetermined threshold if the lamp has not ignited.Type: GrantFiled: July 13, 2009Date of Patent: January 22, 2013Assignee: Microsemi CorporationInventors: George C. Henry, David K Lacombe
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Publication number: 20120081017Abstract: A solid state lighting controller arranged for use with a single stage power factor correction switched mode power supply, a light emitting diode (LED) string and a current sense element arranged to sense current through the LED string, the solid state lighting controller constituted of: a current governor in series with the LED string exhibiting a governor differential amplifier and a governor electronically controlled switch responsive to the output of the governor differential amplifier, the current governor arranged to limit current flow through the LED string responsive to a current limit reference; and a feedback circuit exhibiting an error amplifier, the feedback circuit arranged to feedback a signal to the power factor correction switched mode power supply controller whose value is a function of the difference between the current through the LED string sensed by the current sense element and a target current signal.Type: ApplicationFiled: October 3, 2011Publication date: April 5, 2012Applicant: MICROSEMI CORP. - ANALOG MIXED SIGNAL GROUP LTD.Inventors: Yair DARSHAN, Chii-Fa CHIOU, David K. LACOMBE
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Patent number: 7868603Abstract: A feed-forward correction circuit in a PWM controller adjusts an error signal inversely with respect to a supply voltage for a switching voltage regulator to quickly compensate for changes or transients in the supply voltage. The adjusted error signal is provided to a PWM comparator to control a duty cycle of an output signal. The switching voltage regulator can be a DC-to-DC converter or a DC-to-AC converter, and the output signal is used to generate one or more driving signals to control semiconductor switches in the switching voltage regulator. The feed-forward correction circuit uses an offset compensation technique or a translinear circuit to maintain a substantially inverse product relationship between the supply voltage and the duty cycle of the output signal, thereby reducing overshoots and undershoots in a regulated output voltage of the switching voltage regulator.Type: GrantFiled: October 2, 2007Date of Patent: January 11, 2011Assignee: Microsemi CorporationInventors: David K. Lacombe, Chii-Fa Chiou, George C. Henry
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Publication number: 20090273295Abstract: An apparatus and method for igniting a lamp during a strike mode of an inverter comprising: sequentially controlling a duty cycle sweep and a frequency sweep of driving signals in the inverter to provide an increasing output voltage to the lamp. One embodiment advantageously includes a closed feedback loop to implement the duty cycle sweep and the frequency sweep such that an open lamp voltage is reliably regulated during the strike mode. For example, the closed feedback loop stops the duty cycle sweep or the frequency sweep when the output voltage to the lamp reaches a predetermined threshold and makes adjustments to the duty cycle or frequency the driving signals as needed to keep the output voltage at approximately the predetermined threshold if the lamp has not ignited.Type: ApplicationFiled: July 13, 2009Publication date: November 5, 2009Applicant: Microsemi CorporationInventors: George C. Henry, David K. Lacombe
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Patent number: 7569998Abstract: An apparatus and method for igniting a lamp during a strike mode of an inverter comprising: sequentially controlling a duty cycle sweep and a frequency sweep of driving signals in the inverter to provide an increasing output voltage to the lamp. One embodiment advantageously includes a closed feedback loop to implement the duty cycle sweep and the frequency sweep such that an open lamp voltage is reliably regulated during the strike mode. For example, the closed feedback loop stops the duty cycle sweep or the frequency sweep when the output voltage to the lamp reaches a predetermined threshold and makes adjustments to the duty cycle or frequency the driving signals as needed to keep the output voltage at approximately the predetermined threshold if the lamp has not ignited.Type: GrantFiled: July 5, 2007Date of Patent: August 4, 2009Assignee: Microsemi CorporationInventors: George C. Henry, David K. Lacombe
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Publication number: 20080122379Abstract: An apparatus and method for igniting a lamp during a strike mode of an inverter comprising: sequentially controlling a duty cycle sweep and a frequency sweep of driving signals in the inverter to provide an increasing output voltage to the lamp. One embodiment advantageously includes a closed feedback loop to implement the duty cycle sweep and the frequency sweep such that an open lamp voltage is reliably regulated during the strike mode. For example, the closed feedback loop stops the duty cycle sweep or the frequency sweep when the output voltage to the lamp reaches a predetermined threshold and makes adjustments to the duty cycle or frequency the driving signals as needed to keep the output voltage at approximately the predetermined threshold if the lamp has not ignited.Type: ApplicationFiled: July 5, 2007Publication date: May 29, 2008Applicant: MICROSEMI CORPORATIONInventors: George C. Henry, David K. Lacombe
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Publication number: 20080084196Abstract: A feed-forward correction circuit in a PWM controller adjusts an error signal inversely with respect to a supply voltage for a switching voltage regulator to quickly compensate for changes or transients in the supply voltage. The adjusted error signal is provided to a PWM comparator to control a duty cycle of an output signal. The switching voltage regulator can be a DC-to-DC converter or a DC-to-AC converter, and the output signal is used to generate one or more driving signals to control semiconductor switches in the switching voltage regulator. The feed-forward correction circuit uses an offset compensation technique or a translinear circuit to maintain a substantially inverse product relationship between the supply voltage and the duty cycle of the output signal, thereby reducing overshoots and undershoots in a regulated output voltage of the switching voltage regulator.Type: ApplicationFiled: October 2, 2007Publication date: April 10, 2008Applicant: Microsemi CorporationInventors: David K. Lacombe, Chii-Fa Chiou, George C. Henry
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Patent number: 6496317Abstract: A write driver controls current path for current of an H-bridge circuit. The H-bridge circuit is controlled by a differential pair switch for adjusting a voltage between the differential pair switch between a first voltage when the H-bridge circuit is switched and a second voltage after the H-bridge circuit is switched.Type: GrantFiled: May 7, 1999Date of Patent: December 17, 2002Assignee: Texas Instruments IncorporatedInventor: David K. Lacombe
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Patent number: 6466388Abstract: The present invention achieves technical advantages as an overshoot circuit (30) for a voltage source/impedance based write coil driver circuit (10) accurately controlling the current (IW)through a coil (LH) that is used to write data to a magnetic medium. The circuit (30) improves the characteristics of the coil.Type: GrantFiled: November 17, 2000Date of Patent: October 15, 2002Assignee: Texas Instruments IncorporatedInventors: David K. Lacombe, Chii-Fa Chiou
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Patent number: 6400190Abstract: A write driver to supply current to an induction load, including an H-bridge circuit coupled to the induction load to switch the current between a first current path and a second current path, said induction load operative to generate an undershoot current, and an undershoot circuit to control the undershoot current based on a comparison of a reference voltage and a flyback voltage. The undershoot circuit is connected to bases of the transistors of the lower H-bridge circuit.Type: GrantFiled: May 7, 1999Date of Patent: June 4, 2002Assignee: Texas Instruments IncorporatedInventor: David K. Lacombe
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Publication number: 20010022700Abstract: A write driver controls current path for current of an H-bridge circuit. The H-bridge circuit is controlled by a differential pair switch for adjusting a voltage between the differential pair switch between a first voltage when the H-bridge circuit is switched and a second voltage after the H-bridge circuit is switched.Type: ApplicationFiled: May 7, 1999Publication date: September 20, 2001Inventor: DAVID K. LACOMBE
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Publication number: 20010022699Abstract: An H-bridge circuit driven by a differential pair whereby the differential pair creates a current summation node that controls the H-bridge current magnitude and response.Type: ApplicationFiled: May 7, 1999Publication date: September 20, 2001Inventor: DAVID K. LACOMBE
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Patent number: 5309144Abstract: A security system uses a base unit and a portable transceiver which cooperate to provide automatic monitoring of a secure perimeter. An intrusion sensor is employed to activate a transmitter for emitting a selected frequency wave energy challenge transmission upon the detection of an intruder either outside the perimeter or entering the perimeter. If the intruder has the portable transceiver present to receive the challenge transmission, it automatically emits a responsive wave energy signal as an acknowledgment. A base unit receiver detects the acknowledgment signal and prohibits alarm action. If no acknowledgment signal is received, then either a warning or an alarm is triggered at the base unit. The system does not require manual control. The several distinct wave energy signals can be chosen from among various available radio frequency electromagnetic, and audible or ultrasonic acoustic, waves.Type: GrantFiled: January 14, 1991Date of Patent: May 3, 1994Inventors: David K. Lacombe, George J. Seelman, Michael C. Scofield