Ballast with anti-striation circuit

• US 8,937,437 B2
• Filed: 06/13/2013
• Issued: 01/20/2015
• Est. Priority Date: 06/13/2013
• Status: Expired due to Fees

• Current Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Original Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Inventors: Kumar, Nitin, Bakre, Shashank
• Primary Examiner(s): Tran, Thuy Vinh
• Assistant Examiner(s): Kaiser, Syed M
• Application Number:
  US13/917,414
• Publication Number:
  US 20140368120A1
• Time in Patent Office: 586 Days
• Field of Search: 315/297, 315/200.R, 315/209, 315/224, 315/307
• US Class Current: 315/224
• CPC Class Codes: H05B 41/2988 for protecting the lamp against abnormal operating conditions

Abstract

A ballast comprises an inverter circuit for providing an oscillating current signal for energizing the at least one lamp. The inverter circuit comprises a first switching component and a second switching component each having a collector terminal, a base terminal, and an emitter terminal. And, each switching component is configured for alternately operating between a conductive state and a non-conductive state. A first collector-emitter circuit is connected between the collector terminal and the emitter terminal of the first switching component, wherein the first collector-emitter circuit has a first resistance of zero or more Ohms. A second collector-emitter circuit is connected between the collector terminal and the emitter terminal of the second switching component, wherein the second collector-emitter circuit has a second resistance of zero or more Ohms and the first resistance and the second resistance are unequal.

Claims

1. A ballast comprising:

an inverter circuit to provide an oscillating current signal to energize at least one lamp, wherein the inverter circuit comprises;

a first switching component having a collector terminal, a base terminal, and an emitter terminal, wherein the first switching component is configured to alternately operate between a conductive state and a non-conductive state;

a first collector-emitter circuit connected between the collector terminal and the emitter terminal of the first switching component, wherein the first collector-emitter circuit has a first resistance of zero or more Ohms;

a second switching component having a collector terminal, a base terminal, and an emitter terminal, wherein the second switching component is configured to alternately operate between a conductive state and a non-conductive state; and

a second collector-emitter circuit connected between the collector terminal and the emitter terminal of the second switching component, wherein the second collector-emitter circuit has a second resistance of zero or more Ohms;

wherein the first resistance and the second resistance are unequal, and wherein the first collector-emitter circuit comprises a first diode and a first resistive component connected together in series, and wherein the second collector-emitter circuit comprises a second diode and a second resistive component connected together in series, wherein the resistance of the first resistive component is greater than the resistance of the second resistive component.

2. The ballast of claim 1, wherein the first collector-emitter circuit comprises a diode and a resistive component connected together in series.

3. The ballast of claim 2, wherein the resistive component comprises one or more resistors.

4. The ballast of claim 2, wherein the second collector-emitter circuit comprises a diode.

5. The ballast of claim 1, further comprising:

a rectifier to receive an alternating current (AC) voltage signal and to produce a rectified voltage signal therefrom; and

a power factor correction circuit electrically connected to the rectifier to receive the rectified voltage signal and to provide a corrected voltage signal, wherein the inverter circuit is electrically connected to the power factor correction circuit to receive the corrected voltage signal and to generate the oscillating current signal therefrom.

6. A ballast comprising:

an inverter circuit to provide an oscillating current signal to energize at least one lamp, wherein the inverter circuit comprises;

a first switching component having a collector terminal, a base terminal, and an emitter terminal, wherein the first switching component is configured to alternately operate between a conductive state and a non-conductive state;

a first diode connected between the collector terminal and the emitter terminal of the first switching component;

a second switching component having a collector terminal, a base terminal, and an emitter terminal, wherein the second switching component is configured to alternately operate between a conductive state and a non-conductive state, wherein the collector terminal of the second switching component is connected to the emitter terminal of the first switching component;

a second diode connected between the collector terminal and the emitter terminal of the second switching component; and

a resistive component connected in series with the first diode between the collector terminal and the emitter terminal of the first switching component so a greater resistance is generated across the collector terminal and the emitter terminal of the first switching component than is generated across the collector terminal and the emitter terminal of the second switching component.

7. The ballast of claim 6, wherein the resistive component comprises a resistor.

8. The ballast of claim 6, wherein the resistive component comprises a plurality of resistors connected together.

9. The ballast of claim 6, further comprising:

a rectifier to receive an alternating current (AC) voltage signal and to produce a rectified voltage signal therefrom; and

a power factor correction circuit electrically connected to the rectifier to receive the rectified voltage signal and to provide a corrected voltage signal, wherein the inverter circuit is electrically connected to the power factor correction circuit top receive the corrected voltage signal and to generating the oscillating current signal therefrom.

10. A ballast comprising:

an inverter circuit for providing an oscillating current signal to energize at least one lamp, wherein the inverter circuit comprises;

a first switching component having a collector terminal, a base terminal, and an emitter terminal, wherein the first switching component is configured to alternately operate between a conductive state and a non-conductive state;

a first diode connected between the collector terminal and the emitter terminal of the first switching component;

a second switching component having a collector terminal, a base terminal, and an emitter terminal, wherein the second switching component is configured to alternately operate between a conductive state and a non-conductive state, wherein the collector terminal of the second switching component is connected to the emitter terminal of the first switching component;

a second diode connected between the collector terminal and the emitter terminal of the second switching component; and

a resistive component connected in series with the second diode between the collector terminal and the emitter terminal of the second switching component so a greater resistance is generated across the collector terminal and the emitter terminal of the second switching component than is generated across the collector terminal and the emitter terminal of the first switching component.

11. The ballast of claim 10, wherein the resistive component comprises a resistor.

12. The ballast of claim 10, wherein the resistive component comprises a plurality of resistors connected together.

13. The ballast of claim 11, further comprising:

a rectifier to receive an alternating current (AC) voltage signal and to produce a rectified voltage signal therefrom; and

a power factor correction circuit electrically connected to the rectifier to receive the rectified voltage signal and to provide a corrected voltage signal, wherein the inverter circuit is electrically connected to the power factor correction circuit to receive the corrected voltage signal and to generate the oscillating current signal therefrom.