Patents by Inventor Demetri J. Giannopoulos

Demetri J. Giannopoulos 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).

  • Patent number: 8981753
    Abstract: An electronic circuit (EC) may include an integrated current-source with an output terminal that may couple to the output of a power converter (OPC) to draw current from the power converter. The EC may further include control circuitry for activating the integrated current-source and for effecting a ramping output voltage at the OPC, and begin current-sense calibration once the output voltage reaches a specified calibration voltage value (SCVV). The control circuitry may regulate the output voltage to the SCVV while current-sense calibration is being performed, to measure and store the resistance value of a current-sense element of the power regulator. With the current-sense calibration complete, the control circuitry may disable the integrated current-source, resume ramping the output voltage until it reaches a specified regulation value (SRVV), and regulate to the SRVV during normal operation. The SCVV is specified to be at least a magnitude lower than the SRVV.
    Type: Grant
    Filed: June 27, 2012
    Date of Patent: March 17, 2015
    Assignee: Intersil Americas LLC
    Inventor: Demetri J. Giannopoulos
  • Patent number: 8933681
    Abstract: A novel integrated switched mode power supply circuit that provides supply voltages to an integrated circuit may be of minimal complexity and have the capacity for a wide range of input supply voltages. The novel power supply may include cascaded, unregulated step-down charge pumps (e.g. unregulated voltage splitters), one or more linear regulators coupled to the output of the cascaded voltage splitters, and a start-up current source to provide the IC supply current until the input supply voltage is sufficiently high for the voltage splitter(s) to be functional to provide the IC supply current. Furthermore, each voltage splitter may be activated or disabled depending on the value of the input supply voltage, and the input of a disabled voltage splitter may be shorted to its output via an integrated power switch. Using (cascaded) voltage splitters to provide the IC supply current reduces overall power dissipation in the IC.
    Type: Grant
    Filed: June 27, 2012
    Date of Patent: January 13, 2015
    Assignee: Intersil Americas Inc.
    Inventors: Demetri J. Giannopoulos, Aaron Shreeve
  • Publication number: 20130285628
    Abstract: A novel integrated switched mode power supply circuit that provides supply voltages to an integrated circuit may be of minimal complexity and have the capacity for a wide range of input supply voltages. The novel power supply may include cascaded, unregulated step-down charge pumps (e.g. unregulated voltage splitters), one or more linear regulators coupled to the output of the cascaded voltage splitters, and a start-up current source to provide the IC supply current until the input supply voltage is sufficiently high for the voltage splitter(s) to be functional to provide the IC supply current. Furthermore, each voltage splitter may be activated or disabled depending on the value of the input supply voltage, and the input of a disabled voltage splitter may be shorted to its output via an integrated power switch. Using (cascaded) voltage splitters to provide the IC supply current reduces overall power dissipation in the IC.
    Type: Application
    Filed: June 27, 2012
    Publication date: October 31, 2013
    Inventors: Demetri J. Giannopoulos, Aaron Shreeve
  • Publication number: 20130249518
    Abstract: An electronic circuit (EC) may include an integrated current-source with an output terminal that may couple to the output of a power converter (OPC) to draw current from the power converter. The EC may further include control circuitry for activating the integrated current-source and for effecting a ramping output voltage at the OPC, and begin current-sense calibration once the output voltage reaches a specified calibration voltage value (SCVV). The control circuitry may regulate the output voltage to the SCVV while current-sense calibration is being performed, to measure and store the resistance value of a current-sense element of the power regulator. With the current-sense calibration complete, the control circuitry may disable the integrated current-source, resume ramping the output voltage until it reaches a specified regulation value (SRVV), and regulate to the SRVV during normal operation. The SCVV is specified to be at least a magnitude lower than the SRVV.
    Type: Application
    Filed: June 27, 2012
    Publication date: September 26, 2013
    Inventor: Demetri J. Giannopoulos
  • Patent number: 7554274
    Abstract: The present invention provides a master-slave architecture for a radio frequency RF networked lighting control system having all slave elements (ballasts) configured as backups for a network master control unit. In the system and method of the present invention a slave element can become the network master network unit without reconfiguring the network and without any human intervention. Similarly, both a master and one or more slave elements may recover from a temporary outage without necessitating reconfiguration of the network and without any human intervention.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: June 30, 2009
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Ling Wang, Demetri J. Giannopoulos
  • Publication number: 20090123161
    Abstract: A LED system (100) for illumination and data transmission employs a LED driver (110), an electronic switch (130), and an illumination unit (150). In a first illumination state, illumination unit (150) receives LED current(s) from LED driver (110) to emit a first light output. In a second illumination state, the illumination unit (150) receives additional LED current(s) from LED driver 110 via the electronic switch as controlled by the LED driver where the illumination unit (150) additionally emits a second light output. LED system (100) optically communicates a data bit with each transition of the illumination unit (150) from the first illumination state to the second illumination state, and vice-versa.
    Type: Application
    Filed: January 19, 2009
    Publication date: May 14, 2009
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Xiaohong SUN, DEMETRI J. GIANNOPOULOS
  • Patent number: 7496297
    Abstract: A LED system (100) for illumination and data transmission employs a LED driver (110), an electronic switch (130), and an illumination unit (150). In a first illumination state, illumination unit (150) receives LED current(s) from LED driver (110) to emit a first light output. In a second illumination state, the illumination unit (150) receives additional LED current(s) from LED driver 110 via the electronic switch as controlled by the LED driver where the illumination unit (150) additionally emits a second light output. LED system (100) optically communicates a data bit with each transition of the illumination unit (150) from the first illumination state to the second illumination state, and vice-versa.
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: February 24, 2009
    Assignee: Koninklijke Philips Electronics, N.V.
    Inventors: Xiaohong Sun, Demetri J. Giannopoulos
  • Patent number: 7456589
    Abstract: A method of operating a light source (100) including a ballast (110) in electrical communication with a lamp (120). The method includes operating the ballast (110) to determine (920) an average lamp power to be applied to the lamp (120) during a data period. The method further includes operating the ballast (110) to generate and communicate (930) a pulse width modulated drive signal to the lamp (120) during the data period, the pulse width modulated drive signal having one of a first waveform and a second waveform for applying the average lamp power to the lamp (120), the first waveform including at least one pulse representative of a first data bit, the second waveform including at least one pulse representative of a second data bit.
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: November 25, 2008
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Xiaohong Sun, Demetri J. Giannopoulos, Laurence Bourdillon
  • Patent number: 6359387
    Abstract: A gas discharge lamp has an impedance element such as a capacitor connected to at least one electrode heater, to produce a heater impedance which falls within a range which is unique to lamps of that lamp type. An electronic ballast for operating such lamp has a lamp type detection circuit which measures the cold heater impedance and identifies the corresponding lamp type. The ballast may sample the heater circuit current to determine resistive and reactive components to aid in lamp type identification and to control heater warm-up. The ballast may include a separate inverter for heater power, and control heater power separate from arc power after lamp ignition.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: March 19, 2002
    Assignee: Philips Electronics North America Corporation
    Inventors: Demetri J. Giannopoulos, Ihor T. Wacyk
  • Patent number: 6337544
    Abstract: A digital lamp signal processor senses lamp current and lamp voltage in real time. These two signals are sufficient to obtain information, such as real lamp power calculation, necessary to control ballast operation and fault detection. The apparatus measures the phase of lamp current and voltage, the peak current and voltage, and calculates the average lamp current and voltage. The digital lamp signal processor eliminates the effect of parasitic capacitance of power wiring and a signal condition circuit. It may detect and control hard switching and apply over current and voltage protection. The apparatus directly processes AC signals, allowing for simple and easily integrated single chip design.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: January 8, 2002
    Assignee: Philips Electronics North America Corporation
    Inventors: Shenghong Wang, Demetri J. Giannopoulos, Ihor T. Wacyk
  • Patent number: 6300723
    Abstract: An apparatus for power factor control includes a capacitor for producing a substantially DC voltage and a switch for controlling the amount of energy stored in the capacitor in response to a switching signal. The switching signal is produced by the power factor controller and is based on a sinusoidal waveform that is independent of the waveform of an AC supply voltage for energizing an electric load.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: October 9, 2001
    Assignee: Philips Electronics North America Corporation
    Inventors: Shenghong Wang, Ihor T. Wacyk, Demetri J. Giannopoulos
  • Patent number: 6160361
    Abstract: A ballast for operating different types of lamp loads through identification of the lamp type during steady state operation of the lamp load. Lamp type recognition is achieved based on a comparison of the lamp load voltage and lamp load current data points stored in a random-access memory of a microprocessor to a plurality of V-I characteristic curves stored in a read-only memory of the microprocessor. Through this comparison, the ballast can distinguish among a number of different lamp loads having the same starting voltage.
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: December 12, 2000
    Assignee: Philips Electronics North America Corporation
    Inventors: Demetri J. Giannopoulos, Shenghong Wang
  • Patent number: 6140777
    Abstract: A ballast preconditioner serving as a boost regulator which includes a power factor controller. The preconditioner also includes a capacitor for producing a substantially DC voltage and a switch for controlling the amount of energy stored in the capacitor in response to a switching signal. The power factor controller includes a waveform generator having a look-up table for storing values of at least one waveform. The switching signal produced by the power factor controller is based on the at least one waveform accessed from the look-up table.
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: October 31, 2000
    Assignee: Philips Electronics North America Corporation
    Inventors: Shenghong Wang, Ihor T. Wacyk, Demetri J. Giannopoulos
  • Patent number: 6100647
    Abstract: An electronic ballast for an electron discharge lamp includes a resonant inverter driven by a high frequency switching signal supplied by a drive circuit which is substantially comprised in an integrated circuit, the lamp being connected in an output circuit of the inverter and powered thereby. The lamp intensity is controlled by changing the switching signal frequency, thereby changing the power supplied to the lamp. In order to prevent parasitic capacitance of remote wiring between the ballast and the lamp from causing inaccuracies in determination of the power being supplied to the lamp, the ballast takes into account the phase difference between lamp current and voltage in making such determination. For example, by deriving the product of rectified lamp voltage and rectified lamp current, and using the arithmetic summation of such products during each operating cycle as a measure of lamp power.
    Type: Grant
    Filed: December 28, 1998
    Date of Patent: August 8, 2000
    Assignee: Philips Electronics North America Corp.
    Inventors: Demetri J. Giannopoulos, Ihor T. Wacyk, Sreeraman Venkitasubrahmanian
  • Patent number: 6008590
    Abstract: An integrated circuit control device for driving a half bridge type of inverter. The IC control inverter powers a load including a lamp. The device includes at least one pin, which during the preheat cycle of the lamp is at a high logic level resulting in the coupling of an additional capacitor to an unloaded resonant tank circuit. The overall resonant frequency of the unloaded circuit is reduced making it less likely that a high voltage will be applied to the lamp during preheat. Once the lamp filaments have been preheated the pin is at a low logic level. The low logic level at the pin causes the additional capacitor to be decoupled from the tank circuit. The pin when at the low logic level also receives a signal representing the voltage condition across the lamp.
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: December 28, 1999
    Assignee: Philips Electronics North America Corporation
    Inventors: Demetri J. Giannopoulos, Paul R. Veldman
  • Patent number: 5742134
    Abstract: An inverter for powering a lamp at deep dim levels. Inverter driving circuitry includes a feedback loop which compares desired dim level to signal representing actual lamp power consumption. Reproducibility of desired lighting conditions for different types of lamps powered by the same ballast over a wide range of temperatures is also provided.
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: April 21, 1998
    Assignee: Philips Electronics North America Corp.
    Inventors: Ihor T. Wacyk, Demetri J. Giannopoulos
  • Patent number: 5696431
    Abstract: An inverter driving scheme for detecting when an inverter is in or near a capacitive mode of operation. In response to being within a capacitive mode of operation, the switching frequency is immediately increased to its maximum setting. When a near capacitive mode of operation is detected, the switching frequency is increased at a preset rate. During overvoltage conditions across the lamp combined with a near capacitive mode of operation, the switching frequency is immediately increased to its maximum setting.
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: December 9, 1997
    Assignee: Philips Electronics North America Corporation
    Inventors: Demetri J. Giannopoulos, Paul R. Veldman
  • Patent number: 5680017
    Abstract: A ballast for powering a lamp at deep dim levels. Driving circuitry includes a feedback loop which compares a desired dim level to a signal representing actual lamp power consumption. The loop is closed once the signal representing actual lamp power consumption equals the desired dim level. During ignition, a switch in response to the lamp voltage reaching or exceeding a predetermined threshold opens the feedback loop. The feedback loop is closed once the lamp has been ignited. By closing the loop as soon as the lamp has been ignited, ignition flash is minimized.
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: October 21, 1997
    Assignee: Philips Electronics North America Corporation
    Inventors: Paul R. Veldman, Demetri J. Giannopoulos, Ihor T. Wacyk