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US 8,410,705 B2Granted
LED lighting system with bypass circuit for failed LED
AssigneeRingdale, Inc.
InventorsKlaus Bollmann, Tom C. Penick
Life of this patent
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Abstract
A bypass circuit is provided for each LED in a series to permit continued operation with reduced lighting in the event of an LED failure. The bypass circuit is provided in parallel to the LED and comprises a Zener Diode provided in parallel to a thyristor. Upon LED failure, the voltage across the Zener Diode is increased thereby triggering the thyristor which is maintained in a triggered mode as long as current flows through the series circuit.
Claims10
An LED lighting system comprising:
- a first LED and bypass circuit, the first LED and bypass circuit comprising:
- a first LED circuit portion having a first LED between a first positive and a first negative terminal;
- and
- a first bypass circuit portion provided in parallel to the first LED circuit portion, the first bypass circuit portion having:
- a Zener Diode, said Zener diode having an anode and a cathode, wherein said cathode is electrically coupled with a gate of a thyristor, wherein said anode of said Zener diode is electrically coupled to:
- an anode of said thyristor;
- and
- said positive terminal;
- a resistor, said resistor having a first and a second end, said first end electrically coupled to said cathode of said Zener diode and said second end electrically coupled to:
- a cathode of said thyristor;
- and
- said negative terminal.
9 more elements
A method of controlling a plurality of LEDs in series, the method comprising:
- providing a plurality of LEDs in a series circuit,
- providing a bypass circuit portion in parallel to each LED, the bypass circuit portion having:
- a Zener Diode, said Zener diode having an anode and a cathode, wherein said cathode is electrically coupled with a gate of a thyristor, wherein said anode of said Zener diode is electrically coupled to:
- an anode of said thyristor;
- and
- said positive terminal;
- a resistor, said resistor having a first and a second end, said first end electrically coupled to said cathode of said Zener diode and said second end electrically coupled to:
- a cathode of said thyristor;
- and
- said negative terminal;
- operating the plurality of LEDs in a full-capability mode where each LED is operational;
- and
- upon the failure of an LED, shunting the failed LED with the bypass circuit portion, thereby providing current to all functional LEDs in the series circuit.
10 more elements
Dependencies are inferred from the claim text.