×

Spectral shift control for dimmable AC LED lighting

  • US 9,775,212 B2
  • Filed: 06/27/2016
  • Issued: 09/26/2017
  • Est. Priority Date: 08/14/2009
  • Status: Active Grant
First Claim
Patent Images

1. A method of conditioning current in a light engine steps comprising:

  • providing a pair of input terminals that receive a periodic excitation voltage;

    receiving a current of equal magnitude and opposite polarity into each one of the pair of terminals, said current flowing in response to the excitation voltage;

    providing a plurality of light emitting diodes (LEDs) arranged in a first network, said first network arranged to conduct said current in response to the excitation voltage exceeding at least a forward threshold voltage associated with the first network;

    providing a plurality of LEDs arranged in a second network in series relationship with said first network;

    providing a bypass path in parallel with the second network;

    diverting the current from the first network with dimming conditioning circuitry as a function of the waveform of the periodic excitation voltage; and

    wherein a resistor within the dimming conditioning circuitry dynamically increases an impedance of the bypass path as a substantially smooth and continuous function of said current amplitude in response to said current amplitude increasing in the range above the threshold current.

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