LED lamp arrangement adapted to replace fluorescent lamp in luminaire with ballast

A light emitting diode (LED) lamp arrangement adapted to replace a fluorescent lamp in a luminaire having a ballast for supplying power to the fluorescent lamp, the LED lamp arrangement comprising:

• a rectifier having two inputs configured to be connected to the ballast, the rectifier providing a rectified power line and a ground power line;
• a plurality of LEDs and a LED driver connected in series between the rectified power line and the ground power line, wherein the LED driver regulates a LED driving current through the LEDs;
• an impedance balance circuit configured to be coupled between the inputs;
• a line-voltage controller for controlling the impedance balance circuit in response to a line voltage at the rectified power line, so as to tune an impedance between the inputs and make the line voltage approach to a predetermined target voltage;
• and
• a timer for delaying start of operation of the line-voltage controller by a predetermined period after the line voltage reaches a predetermined value;
• wherein the LEDs have a forward voltage less than the predetermined target voltage.