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

Claim 0:
1. 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 comprises a first light-emitting element and a last light-emitting element,
in each light-emitting string, the anode of the first light-emitting element is electrically coupled to the first power conductor,
the light-emitting elements in each light-emitting string are electrically coupled in series cathode to anode,
in each light-emitting string, the cathode of the last light-emitting element is electrically coupled to a first end of the first resistor and to a collector of the first transistor of the control element associated with the light-emitting string, and
for each control element, (i) a second end of the first resistor is electrically coupled to a base of the first transistor and a collector of the second transistor, (ii) 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 (iii) an emitter of the second transistor is electrically coupled to a second end of the second resistor and to the second power conductor.