Patent ID: 11950337
Assignee: COOLEDGE LIGHTING INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  F | IPC F  H

Claim 40:
41. A lighting system comprising:
a lightsheet comprising:
a substrate;
disposed on the substrate, (i) first and second spaced-apart power conductors and (ii) a plurality of conductive traces;
a plurality of light-emitting strings, each light-emitting string (i) comprising a plurality of interconnected light-emitting elements spaced along the light-emitting string, (ii) having a first end electrically coupled to the first power conductor, and (iii) having a second end electrically coupled to the second power conductor, wherein the power conductors supply power to the light-emitting strings; and
a plurality of control elements each configured to control current to one or more of the light-emitting strings,

wherein:
each control element comprises a first transistor, a second transistor, a first resistor, and a second resistor,
each control element is associated with one of the light-emitting strings,
the light-emitting elements each have an anode and a cathode,
each light-emitting string includes a control element, wherein for each control element, (i) a first end of the first resistor is electrically coupled to a collector of the first transistor, (ii) a second end of the first resistor is electrically coupled to a base of the first transistor and a collector of the second transistor, (iii) an emitter of the first transistor is electrically coupled to a first end of the second resistor and a base of the second transistor, and (iv) an emitter of the second transistor is electrically coupled to a second end of the second resistor,
each light-emitting string comprises (i) a first group of at least one light-emitting element, the first group comprising a first light-emitting element, wherein the anode of the first light-emitting element is electrically coupled to the first power conductor, and (ii) a second group of at least one light-emitting element, the second group comprising a last light-emitting element, wherein the cathode of the last light-emitting element is electrically coupled to the second power conductor, and
for each light-emitting string, the control element is electrically coupled between the first and second groups of light-emitting elements such that the first end of the first resistor is electrically coupled to the cathode of a last light-emitting element in the first group and the second end of the second resistor is electrically coupled to the anode of a first light-emitting element in the second group.