US Patent No. 9,560,710

LIGHT UNIT FOR EMITTING LIGHT AND METHOD FOR DRIVING A LIGHT UNIT


Patent No. 9,560,710
Issue Date January 31, 2017
Title Light Unit For Emitting Light And Method For Driving A Light Unit
Inventorship Johannes Gerrit Jan Beijer, Bavel (NL)
Bertrand Johan Edward Hontele, Breda (NL)
Assignee PHILIPS LIGHTING HOLDING B.V., Eindhoven (NL)

Claim of US Patent No. 9,560,710

1. A lighting unit including a plurality of lighting devices for emitting light, comprising: a connection terminal for receiving
a total current from an external power supply;
a first current path, an end of which is electrically coupled to the connection terminal, the first current path comprising
at least a first light device; and

a second current path, an end of which is electrically coupled to the connection terminal, the second current path comprising
at least a second lighting device, wherein the first current path and the second current path are connected in parallel to
each other and the second current path is electrically conductive while the first current path is electrically nonconductive
when the total current is less than a first threshold current,

wherein the second current path has a current regulator adapted to control an electrical current of the second current path,
a control unit adapted to control the current regulator based on the electrical current of the second current path and based
on the total current, and a current limiter adapted to limit the electrical current in the second current path so as to shape
a plateau in the electrical current of the second current path when the total current is greater than the first threshold
current;

wherein the lighting unit further comprises:
a third current path, an end of which is electrically coupled to the connection terminal, the third current path comprising
at least a third lighting device, wherein the third current path is connected in parallel to the first and second current
paths, and comprises a third current regulator adapted to control a third electrical current of the third current path; and

a third control unit adapted to control the third current regulator based on a weighted sum of the electrical current of the
second current path and the electrical current of the first current path.