ELECTRONIC CIRCUIT FOR DC CONVERSION OF FLUORESCENT LIGHTING BALLAST
First Claim
1. An illumination device including LEDs for connection to an existing fluorescent lamp fixture including a conventional ballast, the ballast configured to provide a current signal, the illumination device comprising:
- protection circuitry configured to protect the illumination device from the ballast current signal;
a full-wave rectifier electrically coupled to the circuit protection means and configured to produce a rectified voltage output;
a smoothing filter electrically coupled to the full wave rectifier and configured to produce a smoothed rectified voltage output; and
a current regulator power circuit electrically coupled to the smoothing filter and the LEDS, the current regulator power circuit including;
a first switching element configured to operate in response to a first pulse width modulated (PWM) ON/OFF control signal, the first switching element delivering current to the LEDs in response to the ON control signal and the first switching element not delivering current to the LEDs in response to the OFF control signal;
a current controller electrically coupled to a gate of the first switching element, the current controller configured to generate the first PWM control signal; and
a current sense resistor electrically coupled to the first switching element and configured to sense the current through the LEDS, wherein the sensed current is fed back to the current controller.
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Accused Products
Abstract
Embodiments of an illumination device including LEDs for connection to an existing fluorescent lamp fixture including a conventional ballast described. One illumination device includes protection circuitry configured to protect the illumination device from the ballast current signal, a full-wave rectifier, a smoothing filter electrically coupled to the full wave rectifier, and a current regulator power circuit electrically coupled to the smoothing filter and the LEDS. The current regulator power circuit can include a first switching element configured to operate in response to a first (PWM) ON/OFF control signal; a current controller electrically coupled to a gate of the first switching element, the current controller configured to generate the first PWM control signal; and a current sense resistor electrically coupled to the first switching element and configured to sense the current through the LEDS, wherein the sensed current is fed back to the current controller.
154 Citations
16 Claims
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1. An illumination device including LEDs for connection to an existing fluorescent lamp fixture including a conventional ballast, the ballast configured to provide a current signal, the illumination device comprising:
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protection circuitry configured to protect the illumination device from the ballast current signal; a full-wave rectifier electrically coupled to the circuit protection means and configured to produce a rectified voltage output; a smoothing filter electrically coupled to the full wave rectifier and configured to produce a smoothed rectified voltage output; and a current regulator power circuit electrically coupled to the smoothing filter and the LEDS, the current regulator power circuit including; a first switching element configured to operate in response to a first pulse width modulated (PWM) ON/OFF control signal, the first switching element delivering current to the LEDs in response to the ON control signal and the first switching element not delivering current to the LEDs in response to the OFF control signal; a current controller electrically coupled to a gate of the first switching element, the current controller configured to generate the first PWM control signal; and a current sense resistor electrically coupled to the first switching element and configured to sense the current through the LEDS, wherein the sensed current is fed back to the current controller. - View Dependent Claims (2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13)
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8. A method of supplying power to an illumination device including LEDs and connected to an existing fluorescent lamp fixture including a conventional ballast, the method comprising:
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receiving a current signal from the conventional ballast; protecting the illumination device from the received current signal; rectifying the received current signal to produce a rectified voltage output; sensing current through the LEDs; generating a pulse width modulated (PWM) control signal from a current control circuit based on the sensed current; and supplying current to the LEDs in response to the PWM control signal so that the LED current reaches an average LED current.
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14. An illumination device including LEDs for connection to an existing fluorescent lamp fixture including a conventional ballast, the illumination device comprising:
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means for receiving a current signal from the conventional ballast; means for protecting the illumination device from the received current signal; means for rectifying the received current signal to produce a rectified voltage output; means for sensing the current through the LEDs; means for generating a pulse width modulated (PWM) control signal from a current control circuit based on the sensed current; and means for supplying current to the LEDs in response to the PWM control signal so that the LED current reaches an average LED current. - View Dependent Claims (15, 16)
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Specification