Patent ID: 9414450
Filing Date: 2016-08-09
CPC Classification: H05B

Claim Text:
1. A lighting circuit for mains LED lighting applications operable with a phase-cut dimmer, wherein the mains has a maximum voltage which is at least 200V, the circuit comprising: a rectifier having a low side output and a high side output; a switched mode converter comprising a switch and an inductive element, having a high side input connected to a bus rail, and having a configuration so as to draw current from the mains across a complete mains cycle; a controller for the switched mode converter; a filter circuit connected between the rectifier high side output and the bus rail and comprising a capacitor connected between the high side output of the rectifier and ground; and a combined damping/latch resistance connected between the low side output of the rectifier and ground; wherein the value of the combined damping/latch resistance is such that the RC time constant of the combined damping/latch resistance and filter circuit is greater than the time required for any ringing in the circuit to fall to no more than 20 mA.