Inverter circuits

  • US 4,677,345 A
  • Filed: 05/11/1981
  • Issued: 06/30/1987
  • Est. Priority Date: 08/14/1980
  • Status: Expired due to Term
First Claim
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1. A power supply operable to energize a gas discharge lamp at adjustable illumination levels, comprising:

  • an inverter circuit having at least one periodically conducting transistor in circuit with a DC voltage input and being operable to provide an AC voltage output;

    frequency dependent impedance means connected in circuit between the AC voltage output and the lamp; and

    an AC current output operable to connect withcontrol means connected with the inverter circuit and operative to control the transistor inversion frequency and correspondly;

    (i) the impedance of the frequency dependent impedance means, and (ii) the magnitude of the AC current supplied to the lamp;

    the control means being separate from and independent of the frequency dependent impedance means.

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