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Arrangement for digital brightness control of lamps

  • US 4,396,871 A
  • Filed: 02/19/1981
  • Issued: 08/02/1983
  • Est. Priority Date: 03/03/1980
  • Status: Expired due to Fees
First Claim
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1. An arrangement for digital brightness control of lamps in control channels, particularly for use in planetaria illuminations, comprisingat least one lamp,at least one power control stage for brightness control of said lamp in digitally divided steps of a brightness raster,at least one programmable counter having a counter input, a set input and an output,at least a bistable flip-flop having two inputs and one output,at least a gate circuit having two inputs and one output,said lamp, said power control stage, said counter, said flip-flop and said gate circuit constituting one of said control channels,said output of said flip-flop being connected to one of said two inputs of said gate circuit and to said input of said power control stage,said output of said power control stage being connected to said lamp,said gate circuit output being connected to said counter input, said counter output being connected to one of said two flip-flop inputs,said counter being programmable via said set input,a mains synchronizing stage having two inputs and one output,said synchronizing stage being for producing mains synchronous pulses,said output of said synchronizing stage being connected to the other of said two flip-flop inputs,a voltage source being connected to the one of said two inputs of said synchronizing stage,a pulse generator being connected to the other of said two inputs of said synchronizing stage and to the other of said two inputs of said gate circuit,said pulse generator being for producing a pulse sequence frequency corresponding to the frequency of the mains synchronous pulses divided by steps determined by the bit number of said brightness raster.

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