Patents by Inventor Dolf Henricus Jozef Van Casteren

Dolf Henricus Jozef Van Casteren 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: 6919695
    Abstract: The present invention relates to a device for operating a high-pressure discharge lamp, comprising a switched mode power supply circuit (SMPS) for supplying power to the high pressure discharge lamp from a supply voltage, the power supply circuit comprising a half bridge commutating forward (HBCF) circuit including an inductance(Lhbcf?), a capacitor circuit of a first capacitor (Cs1) and a second capacitor (Cs2) in series, the lamp (LA) being connectable between the inductance (Lhbcf) and a point (M) between the first and second capacitor (Cs1,Cs2); wherein overvoltage protection means are connected parallel to the lamp, which switch from an off-state with a high resistance operation to an on-state with a low resistance operation when the voltage difference across the protection means exceeds a breakover voltage (Vbo), the breakover voltage (Vbo) being selected to correspond to a predetermined maximum voltage across the first or the second capacitor (Cs1,Cs2).
    Type: Grant
    Filed: July 5, 2002
    Date of Patent: July 19, 2005
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Dolf Henricus Jozef Van Casteren
  • Publication number: 20040183459
    Abstract: The present invention relates to a device for operating a high-pressure discharge lamp, comprising a switched mode power supply circuit (SMPS) for supplying power to the high pressure discharge lamp from a supply voltage, the power supply circuit comprising a half bridge commutating forward (HBCF) circuit including an inductances (Lhbcf?), a capacitor circuit of a first capacitor (Cs1) and a second capacitor (Cs2) in series, the lamp (LA) being connectable between the inductance (Lhbcf) and a point (M) between the first and second capacitor (Cs1,Cs2); wherein overvoltage protection means are connected parallel to the lamp, which switch from an off-state with a high resistance operation to an on-state with a low resistance operation when the voltage difference across the protection means exceeds a breakover voltage (Vbo), the breakover voltage (Vbo) being selected to correspond to a predetermined maximum voltage across the first or the second capacitor (Cs1,Cs2).
    Type: Application
    Filed: January 14, 2004
    Publication date: September 23, 2004
    Inventor: Dolf Henricus Jozef Van Casteren
  • Publication number: 20040183460
    Abstract: The present invention relates to an Electronic ballast for operating a high-pressure discharge lamp, comprising a switched-mode power supply circuit (SMPS) for supplying a rail voltage Vrail to the high pressure discharge lamp, the power supply circuit comprising a half bridge commutating forward circuit including an inductance (Lhbcf), a capacitor circuit of a first capacitor (Cs1) and a second capacitor (Cs2) in series, the lamp (LA) being connectable between the inductance (Lhbcf) and a midpoint (M) between the first and second capacitor (Cs1,Cs2); a duty cycle control circuit, connected to the switched-mode power supply circuit, for controlling the duty cycle of the half bridge commutating forward circuit; and overvoltage protection means for protecting said capacitors against overvoltage, comprising—a midpoint voltage detection circuit for detecting the voltage at the midpoint between the first and second capacitor, the midpoint voltage detection circuit providing a first signal representative of t
    Type: Application
    Filed: January 14, 2004
    Publication date: September 23, 2004
    Inventor: Dolf Henricus Jozef Van Casteren
  • Patent number: 6548963
    Abstract: The invention relates to a circuit for operating a high-pressure discharge lamp, which circuit is provided with means for operating the connected lamp in a dimmed state by means of a dimming signal Ds. The circuit is provided with: input terminals for connecting the circuit to a power supply source, output terminals for connecting the lamp to be operated, a switch-mode power supply (smps) having a converter provided with a semiconductor switch for generating a converter output voltage across buffer capacitor means, and a control circuit for generating a control signal in dependence on the dimming signal Ds for controlling the semiconductor switch. According to the invention, the circuit is further provided with means for generating a converter output voltage-related signal Lvs for monitoring stable lamp operation by limiting the dimmed state by means of the control circuit.
    Type: Grant
    Filed: August 27, 2001
    Date of Patent: April 15, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Dolf Henricus Jozef Van Casteren, Oscar Jan Deurloo
  • Patent number: 6515432
    Abstract: A circuit for operating a high-pressure discharge lamp with successive current periods, which circuit is provided with means for operating the connected lamp by means of a dimming signal Ds from a first state to a second state, which circuit is further provided with: input terminals for connecting the circuit to a power supply source, output terminals for connecting the lamp to be operated, a switch-mode power supply (smps) having a converter with a semiconductor switch for generating a converter output voltage across buffer capacitor means having a capacitance, and a control circuit for generating a control signal which is intended to control the switch and depends on the dimming signal. The circuit is provided with means for adjusting the capacitance of the buffer capacitor means.
    Type: Grant
    Filed: August 27, 2001
    Date of Patent: February 4, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Dolf Henricus Jozef Van Casteren, Oscar Jan Deurloo
  • Publication number: 20020047598
    Abstract: The invention relates to a circuit for operating a high-pressure discharge lamp, which circuit is provided with means for operating the connected lamp in a dimmed state by means of a dimming signal Ds.
    Type: Application
    Filed: August 27, 2001
    Publication date: April 25, 2002
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V
    Inventors: Dolf Henricus Jozef Van Casteren, Oscar Jan Deurloo
  • Publication number: 20020047599
    Abstract: The invention relates to a circuit for operating a high-pressure discharge lamp with successive current periods, which circuit is provided with means for operating the connected lamp by means of a dimming signal Ds from a first state to a second state, which circuit is further provided with:
    Type: Application
    Filed: August 27, 2001
    Publication date: April 25, 2002
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Dolf Henricus Jozef Van Casteren, Oscar Jan Deurloo