US 11,812,525 B2
Methods and apparatus for controlling the current supplied to light emitting diodes
Tony Wang, Sands Point, NY (US); and Voravit Puvanakijjakorn, Port Washington, NY (US)
Assigned to Wangs Alliance Corporation, Port Washington, NY (US)
Filed by Wangs Alliance Corporation, Port Washington, NY (US)
Filed on Jun. 26, 2018, as Appl. No. 16/019,467.
Claims priority of provisional application 62/525,334, filed on Jun. 27, 2017.
Prior Publication US 2018/0376555 A1, Dec. 27, 2018
Int. Cl. H05B 45/20 (2020.01); H05B 45/395 (2020.01)
CPC H05B 45/20 (2020.01) [H05B 45/395 (2020.01)] 19 Claims
OG exemplary drawing
 
1. A light emitting diode (LED) circuit comprising:
two or more circuit branches coupled in parallel across a two terminal direct current (DC) voltage input including a positive input terminal and a negative input terminal;
each of said two or more circuit branches including a set of light emitting diodes, each of said set of light emitting diodes including at least one light emitting diode; and
at least one of said circuit branches including a current control circuit that is configured to maintain a current passing through at least one of said two or more circuit branches in response to a decrease in DC voltage received from the two DC voltage input terminals, the control circuit consisting of:
a first resistor;
a second resistor;
a shunt regulator; and
a transistor;
wherein:
the two or more circuit branches include:
a first circuit branch; and
a second circuit branch; and
the first and second circuit branches are coupled together only via the positive input terminal and the negative input terminal of the two terminal direct current (DC) voltage input
wherein said first resistor has a first resistor terminal and a second resistor terminal, and said second resistor has a first resistor terminal and a second resistor terminal;
wherein said transistor is a NPN transistor having a collector terminal, an emitter terminal and a base terminal; and
wherein said shunt regulator includes a reference terminal, an anode terminal and a cathode terminal.