Patent ID: 6211625
Filing Date: 2001-04-03
Classification: H02M,H03K,H05B,Y02B

Abstract:
An arrangement comprising:a power source operative to supply a power line voltage at a pair of power line terminals;a first circuit assembly connected with the power line terminals and operative to provide a DC voltage between a pair of DC output terminals;a gas discharge lamp having a pair of lamp terminals and being functional to provide luminous output when supplied with a usual amount of lamp current; anda second circuit assembly having a pair of DC input terminals connected with the DC output terminals and a pair of AC output terminals connected with the lamp terminals; the second circuit assembly being further characterized by:(a) having a tuned L-C circuit connected with the AC output terminals; the L-C circuit having a tank-inductor and a tank-capacitor; the tank-capacitor being effectively connected across the AC output terminals; and(b) producing an AC output voltage across the AC output terminals; the magnitude of the AC output voltage being determined by: (i) a Q-multiplying effect associated with the L-C circuit; (ii) the amount of power drawn by the lamp from the AC output terminals; and (iii) an internal feedback effect responsive to the magnitude of the AC output voltage and operative to diminish the Q-multiplying effect by causing the frequency of the AC output voltage to change away from the natural resonance frequency of the L-C circuit; such that the internal feedback effect is functional, under a condition when no power is being drawn from the AC output terminals, to cause the magnitude of the AC output voltage to be lower than it would have been if determined solely by said Q-multiplying effect;such that the magnitude of the AC output voltage is: (i) at a minimum level whenever the lamp is drawing its usual lamp current; and (ii) at a maximum level whenever the lamp fails to draw power, the maximum level being distinctly lower than a level which would have prevailed in the absence of said internal feedback effect.