Ballast circuit with a capacitive and inductive feedback path
First Claim
1. A circuit including a rectifier having at least one rectifying diode, the circuit comprising:
- a first inductive element; and
a capacitor coupled to the first inductive element such that the capacitor and the first inductive element resonate in series and generate a feedback signal that is effective to periodically bias the at least one rectifying diode to a conductive state.
2 Assignments
0 Petitions
Accused Products
Abstract
A circuit including a rectifier having rectifying diodes has a feedback signal which provides substantially linear operation of the rectifying diodes. In one embodiment, a ballast circuit includes a rectifier circuit coupled to an inverter circuit which energizes a fluorescent lamp. The inverter circuit includes a ballast capacitor coupled to an inductive feedback element. The voltages generated across the ballast capacitor and the feedback element combine to provide a feedback signal that is effective to periodically bias at least one of the rectifying diodes to a conductive state during substantially the entire AC input signal. The substantially linear operation of the rectifying diodes enhances THD and PF performance of the circuit.
98 Citations
30 Claims
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1. A circuit including a rectifier having at least one rectifying diode, the circuit comprising:
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a first inductive element; and a capacitor coupled to the first inductive element such that the capacitor and the first inductive element resonate in series and generate a feedback signal that is effective to periodically bias the at least one rectifying diode to a conductive state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A ballast circuit for energizing a lamp, comprising:
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a rectifier circuit including first and second rectifying diodes, the rectifier circuit having an AC input adapted for receiving an AC input signal and a DC output; an inverter circuit coupled to the DC output of the rectifier circuit, the inverter circuit providing a feedback signal to the rectifier circuit at a point between the first and second rectifying diodes via a feedback path, the inverter circuit including at least one switching element; a first inductive element coupled to the at least one switching element, the first inductive element adapted for coupling to the lamp; a second inductive element inductively coupled to the first inductive element, the second inductive element being adapted for coupling to the lamp; and a ballast capacitor coupled to the second inductive element; wherein the feedback path is coupled to a point between the second inductive element and the lamp. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A ballast circuit for energizing a lamp, comprising;
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a rectifier circuit including first and second rectifying diodes, the rectifier circuit having an AC input adapted for receiving an AC input signal and a DC output; an inverter circuit coupled to the DC output side of the rectifier circuit, the inverter circuit providing a feedback signal to the rectifier circuit at a point between the first and second rectifying diodes via a feedback path, the inverter circuit including at least one switching element; first and second inductive elements coupled to the at least one switching element; a ballast capacitor for coupling to the lamp; and an inductive feedback element inductively coupled to the first and second inductive elements, wherein the feedback path includes the inductive feedback element such that the feedback path extends from the point between the first and second rectifying diodes to the ballast capacitor. - View Dependent Claims (18, 19, 20, 21, 22)
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23. A ballast circuit for energizing a lamp, comprising:
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a rectifier circuit having first, second, third and fourth rectifying diodes coupled in a full bridge configuration, the rectifier having first and second AC input terminals for receiving an AC input signal and a DC output, the rectifier further including first and second capacitors coupled end to end between the first and second AC input terminals; a full bridge inverter circuit coupled to the DC output of the rectifier, the inverter circuit including at least one switching element; first and second inductive elements coupled to the at least one switching element; a ballast capacitor for coupling to the lamp; an inductive feedback element inductively coupled to the first and second inductive elements, the feedback inductive element being coupled to the ballast capacitor and to a point between the first and second capacitors. - View Dependent Claims (24, 25, 26, 27, 28, 29)
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30. A ballast circuit for energizing a lamp, comprising:
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a rectifier circuit having first, second, third and fourth rectifying diodes coupled in a full bridge configuration, the rectifier having first and second AC input terminals for receiving an AC input signal and a DC output, the rectifier further including first and second capacitors coupled end to end between the first and second AC input terminals; a full bridge inverter circuit coupled to the DC output of the rectifier, the inverter circuit including at least one switching element; first and second inductive elements coupled to the at least one switching element; a ballast capacitor for coupling to the lamp; and an inductive feedback element inductively coupled to the first and second inductive elements, the feedback inductive element, the lamp and the ballast capacitor being coupled so as to form a series circuit path, wherein a feedback path extends from a point between the first and second capacitors to a point between the lamp and the feedback element.
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Specification