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Digital lighting control system

  • US 4,241,295 A
  • Filed: 02/21/1979
  • Issued: 12/23/1980
  • Est. Priority Date: 02/21/1979
  • Status: Expired due to Term
First Claim
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1. A circuit system for controlling the intensity of a plurality of lights comprising, in combination:

  • a means for producing a binary coded intensity indicating signal for each channel indicating the desired intensity for said channel,a means for communicating said binary coded intensity indicating signal from said production means to a trigger pulse generator means,one or more trigger pulse generator means disposed to receive said binary coded intensity indicating signal and produce during each half-cycle of the AC line voltage a trigger pulse signal for each channel the phase relation of which pulse signal to the AC line is a function of the said binary coded intensity indicating signal,one or more means for producing a nonlinear binary timebase signal controlling the transfer characteristics of said trigger pulse generating means comprising a timebase clock, a memory means, an address counter and a timing counter connected such that the address counter sequentially addresses the memory means and is incremented by a timing counter overflow and such that the timing counter reads data from the memory and counts the difference between the value of said data and a fixed value at a rate determined by a timebase clock and where the operation of said means is repeated for each half-cycle of the AC line,one or more thyristors connected so as to vary the power available to a lamp connected in series with said thyristor and the AC line in response to the varying of the phase relation to the AC line voltage of the trigger pulse signal applied to said thyristor.

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