×

Discharge lamp ballast having an auto-transformer for high voltage detection

  • US 8,207,680 B2
  • Filed: 11/25/2009
  • Issued: 06/26/2012
  • Est. Priority Date: 11/25/2008
  • Status: Expired due to Fees
First Claim
Patent Images

1. A discharge lamp ballast comprising:

  • a power supply circuit further comprising an inverter circuit configured to convert a DC voltage obtained from a DC power source into a voltage having a determined frequency, and further configured to supply the converted voltage to a discharge lamp inserted between a pair of output ends of the inverter circuit;

    a resonant circuit further comprising an auto-transformer and a resonant capacitor, the resonant circuit configured for supplying an output voltage corresponding to a frequency of the converted voltage of the power supply circuit to the discharge lamp;

    a voltage detection circuit for detecting an output voltage of the resonant circuit based on a potential of the resonant capacitor; and

    a control circuit having a startup control mode wherein the control circuit is configured to determine the frequency of the converted voltage based on the detected voltage from the voltage detection circuit, wherein the output voltage of the resonant circuit exceeds a starting voltage of the discharge lamp.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×