Patent ID: 9717120
Date: 2017-07-25
CPC Classifications: H05B,Y02B

Claim:
1. A passive lighting circuit comprising a variable input inductor for receiving an AC input power, the variable input inductor being arranged to filter the AC input power, limit a power flow into an LED load having at least one LED, reduce the sensitivity of LED power to fluctuations in the AC input power, and be selectively controlled for dimming the at least one LED; a rectification circuit connected directly with an output of the variable input inductor, the rectification circuit being arranged to receive the filtered AC input power from the input inductor, rectify the AC input power, and generate a rectified DC power; a non-electrolytic capacitor connected across an output of the rectification circuit for reducing a voltage ripple of said rectified DC power; a current ripple reduction circuit formed by an inductor connected directly between the non-electrolytic capacitor and the LED load, the current ripple reduction circuit being arranged to generate a current to be provided to the LED load; the LED load with at least one LED for receiving said current as an input; wherein the current supplied to said at least one LED is a continuous direct current that is permitted to vary periodically between a non-zero maximum value and a non-zero minimum value, and wherein the operating and/or design parameters of said at least one LED are chosen such that the variation in luminous flux resulting from the variation in the continuous direct current is not observable to the human eye; and wherein the passive LED lighting circuit that is free of active electronic switches, electronic control circuits for the switches, power supplies for the electronic control circuits, and electrolytic capacitors.