Electronic ballast and lighting fixture
First Claim
1. An electronic ballast, comprising:
- a direct current power supply configured to provide a direct current voltage;
a switching circuit, including first and second switching elements, connected in parallel with the direct current power supply, configured to convert the direct current voltage to a high-frequency alternating current;
a load circuit, including a discharge lamp, a resonance inductor, and a resonance capacitor, being operated by the high-frequency alternating current;
a driving circuit, arranged between the switching circuit and the load circuit, provided with feedback windings magnetically connected to a detecting winding of the current transformer, and configured to control a switching frequency of the first and second switching elements according to a detected current of the detecting winding;
a magnetic energy control means, configured to control a magnetic energy of the current transformer;
a current detecting means detecting an average current either an output current of the direct current power supply or a current of the switching circuit; and
a current control means, configured to control the magnetic energy control means, and to fix the average current to a designated value.
1 Assignment
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Accused Products
Abstract
An electronic ballast comprises a direct current power supply configured to provide a direct current voltage.
A switching circuit, including first and second switching elements, is connected in parallel with the direct current power supply, and is configured to convert the direct current voltage to a high-frequency alternating current.
A load circuit, including a discharge lamp, a resonance inductor, and a resonance capacitor, is operated by the high-frequency alternating current. A driving circuit is arranged between the switching circuit and the load circuit.
A driving circuit is provided with feedback windings magnetically connected to a detecting winding of the current transformer. A driving circuit is configured to control a switching frequency of the first and second switching elements according to a detected current of the detecting winding.
A magnetic energy control means is configured to control a magnetic energy of the current transformer.
A current detecting means detects an average current either an output current of the direct current power supply or a current of the switching circuit.
A current control means is configured to control the magnetic energy control means, and to fix the average current to a designated value.
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Citations
3 Claims
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1. An electronic ballast, comprising:
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a direct current power supply configured to provide a direct current voltage;
a switching circuit, including first and second switching elements, connected in parallel with the direct current power supply, configured to convert the direct current voltage to a high-frequency alternating current;
a load circuit, including a discharge lamp, a resonance inductor, and a resonance capacitor, being operated by the high-frequency alternating current;
a driving circuit, arranged between the switching circuit and the load circuit, provided with feedback windings magnetically connected to a detecting winding of the current transformer, and configured to control a switching frequency of the first and second switching elements according to a detected current of the detecting winding;
a magnetic energy control means, configured to control a magnetic energy of the current transformer;
a current detecting means detecting an average current either an output current of the direct current power supply or a current of the switching circuit; and
a current control means, configured to control the magnetic energy control means, and to fix the average current to a designated value.
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2. An electronic ballast, comprising:
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a direct current power supply configured to provide a fixed direct current voltage;
a switching circuit, including first and second switching elements, connected in parallel with the direct current power supply, configured to convert the direct current voltage to a high-frequency alternating current;
a load circuit, including a discharge lamp, a resonance inductor, and a resonance capacitor, being operated by the high-frequency alternating current;
a driving circuit, provided with a detecting winding of a current transformer, and configured to control a switching frequency of the first and second switching elements according to a detected current of the detecting winding;
a magnetic energy control means, including a base of a transistor, configured to control a magnetic energy of the current transformer;
a current detecting means detecting an average current either an output current of the direct current power supply or a current of the switching circuit; and
a current control means, configured to control the magnetic energy control means and to fix the average current to a designated value, provided with a comparator, wherein the comparator compares a voltage signal of the average current with a reference voltage, and its output supplies to a base current of the base of the transistor.
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3. A lighting fixture, comprising:
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a body;
lamp sockets, constructed and arranged on the body; and
an electronic ballast, comprising;
a direct current power supply configured to provide a direct current voltage;
a switching circuit, including first and second switching elements, connected in parallel with the direct current power supply, configured to convert the direct current voltage to a high-frequency alternating current;
a load circuit, including a discharge lamp, a resonance inductor, and a resonance capacitor, being operated by the high-frequency alternating current;
a driving circuit, arranged between the switching circuit and the load circuit, provided with feedback windings magnetically connected to a detecting winding of the current transformer, and configured to control a switching frequency of the first and second switching elements according to a detected current of the detecting winding;
a magnetic energy control means, configured to control a magnetic energy of the current transformer;
a current detecting means detecting an average current either an output current of the direct current power supply or a current of the switching circuit; and
a current control means, configured to control the magnetic energy control means, and to fix the average current to a designated value.
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Specification