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US 12,747,849 B2Granted
Photoluminescent sign with transient-suppressed LED circuit
AssigneeEcoglo International Limited
InventorsRoger Mckenzie, Trevor Dimond
Life of this patent
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Abstract
The invention relates to photoluminescent signs, in particular to signs in which one or more light emitting diodes (LEDs) emit light that excites one or more photoluminescent (PL) elements. In one aspect, a sign may include one or more photoluminescent elements; one or more light emitting diodes (LEDs) arranged to excite the one or more photoluminescent elements; and circuitry arranged for connection to an AC power supply and supplying power to the LEDs.
Claims18
A sign comprising:
- one or more photoluminescent elements;
- and
- an electrical circuit comprising
- an AC circuit;
- a rectifier;
- and
- a DC circuit portion;
- wherein the DC circuit portion comprises one or more light emitting diodes (LEDs), the one or more light emitting diodes (LEDs) arranged to excite the one or more photoluminescent elements;
- wherein the AC circuit is connected to an AC power source and supplies power to the rectifier and the rectifier supplies a rectified power supply to the DC circuit portion;
- wherein the AC circuit receives AC power from an AC source, the AC circuit configured to reduce a transient current supplied to the rectifier;
- wherein the AC circuit comprises
- a first transient suppression circuit used during normal operation, where power runs in series through at least two capacitors and at least two resistors to the rectifier, the first transient suppression circuit configured to act to reduce a voltage and current of the AC source to a level suitable for powering the LEDs;
- wherein the AC circuit is configured to reduce the transient current supplied to the rectifier to less than 1/100th of an original transient size entering the AC circuit arranged for connection to an AC power supply and supplying power to the LEDs.
10 more elements
A sign comprising:
- one or more photoluminescent elements;
- and
- an electrical circuit comprising
- an AC circuit;
- a rectifier;
- and
- a DC circuit portion;
- wherein the DC circuit portion comprises one or more light emitting diodes (LEDs), the one or more light emitting diodes (LEDs) arranged to excite the one or more photoluminescent elements;
- wherein the AC circuit is connected to an AC power source and supplies power to the rectifier and the rectifier supplies a rectified power supply to the DC circuit portion;
- wherein the AC circuit receives AC power from an AC source, the AC circuit configured to reduce a transient current supplied to the rectifier;
- wherein the AC circuit comprises
- a first transient suppression circuit used during normal operation, where power runs in series through at least two capacitors and at least two resistors to the rectifier, the first transient suppression circuit configured to act to reduce a voltage and current of the AC source to a level suitable for powering the LEDs, and
- a shunt transient suppression device connected in parallel located after the at least two resistors of the first transient suppression circuit;
- wherein the AC circuit is configured to reduce the transient current supplied to the rectifier to less than 1/100th of an original transient size entering the AC circuit arranged for connection to an AC power supply and supplying power to the LEDs;
- wherein the LEDs are powered by substantially unsmoothed rectified power at twice a frequency of the AC power supply, resulting in a flicker of the LEDs at twice the frequency of the AC power supply.
12 more elements
Dependencies are inferred from the claim text.