Multiple strike ballast with lamp protection for electrodeless lamp

Patent metadata

Field	Value
Publication number	US-9301375-B2
Application number	US-201314064837-A
Country	US
Kind code	B2
Filing date	Oct 28, 2013
Priority date	Apr 29, 2011
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

A multi-strike ballast to ignite an electrodeless lamp is disclosed, and includes an inverter circuit, a protection circuit, and a controller. The inverter circuit, upon activation, sends an ignition pulse to the lamp. The inverter circuit shuts down upon receiving a deactivation signal, and activates upon receiving an activation signal, triggering another ignition pulse. The protection circuit senses a change in a voltage associated with the lamp. The sensed changed may indicate that the lamp has not yet ignited or that the lamp is broken. The controller receives the sensed change in voltage and, in response, sends a deactivation signal to the inverter circuit. The controller waits a predetermined time and then sends an activation signal to the inverter circuit. The controller repeats until a change in voltage associated with the lamp is not sensed, or until a predefined number of repeats occur, providing multiple ignition pulses to the lamp.

First claim

What is claimed is:

1. A multi-strike ballast to ignite an electrodless lamp, the multi-strike ballast comprising:
an inverter circuit configured to send an ignition pulse to the electrodeless lamp following activation of the inverter circuit, to shut down upon receiving a deactivation signal, and to activate upon receiving an activation signal;
a protection circuit configured to sense a change in voltage associated with the electrodeless lamp;
a controller, wherein the controller is configured to receive the sensed change in voltage associated with the electrodeless lamp from the protection circuit and in response to send a deactivation signal to the inverter circuit, to wait a predetermined time, following the predetermined time to send an activation signal to the inverter circuit, and to repeat until the protection circuit does not sense a change in voltage associated with the electrodeless lamp or until a predefined number of repeats occur; and
a buck converter, wherein the buck converter is configured to receive the activation signal and the deactivation signal from the controller, such that the buck converter controls activation and shut down of the inverter circuit based on the signal received from the controller.

2. The multi-strike ballast of claim 1 , wherein the protection circuit comprises:
a first zener diode and a second zener diode, each including an anode and a cathode, wherein the cathode of the first zener diode is connected to the cathode of the second zener diode, and wherein the anode of the first zener diode is connected to the inverter circuit;
a capacitor connected to a cathode of a first rectifier diode;
a resistor connected in parallel with the capacitor and the first rectifier diode;
a first resistor connected in a series to a second resistor, wherein the second resistor is connected in series to a second rectifier diode, wherein the series connected first resistor, second resistor, and second rectifier diode are in parallel with the first rectifier diode; and
a filter capacitor in parallel with the first resistor.

3. The multi-strike ballast of claim 2 , wherein the protection circuit is connected to the controller at a connection point between the first resistor and the second resistor.

4. The multi-strike ballast of claim 3 , wherein the controller includes an ADC DEGAS pin, and wherein the protection circuit is connected to the controller at the ADC DEGAS pin.

5. The multi-strike ballast of claim 1 , wherein the protection circuit is configured to sense a change in voltage associated with the electrodeless lamp, wherein the change in voltage is due to a broken electrodeless lamp or an electrodeless lamp that has not yet ignited.

6. A method of igniting an electrodeless lamp, comprising:
sensing a change in voltage associated with the electrodeless lamp, the electrodeless lamp having received a first ignition pulse from an activated inverter circuit;
receiving the sensed change in voltage;
in response, deactivating the inverter circuit;
waiting a predetermined time;
in response, reactivating the inverter circuit; and
sending a second ignition pulse to the electrodeless lamp;
wherein sensing is performed by a protection circuit, wherein the protection circuit comprises:
a first zener diode and a second zener diode, each including an anode and a cathode, wherein the cathode of the first zener diode is connected to the cathode of the second zener diode, and wherein the anode of the first zener diode is connected to the inverter circuit;
a capacitor connected to a cathode of a first rectifier diode;
a resistor connected in parallel with the capacitor and the first rectifier diode;
a first resistor connected in a series to a second resistor, wherein the second resistor is connected in series to a second rectifier diode, wherein the series connected first resistor, second resistor, and second rectifier diode are in parallel with the first rectifier diode; and
a filter capacitor in parallel with the first resistor.

7. The method of claim 6 , further comprising:
repeating the steps of sensing, receiving, deactivating, waiting, reactivating, and sending, until the electrodeless lamp ignites.

8. The method of claim 6 , further comprising:
repeating the steps of sensing, receiving, deactivating, waiting, reactivating, and sending, until a predetermined number of repeats occurs.

Assignees

• Osram Sylvania Inc

Inventors

• Kumar Nitin
• Ziegler Markus
• Bakre Shashank
• Choudhury Ayan

Classifications

• Y02B20/22

  Cross-Sectional Technologies · mapped topic

• H05B41/2806 Primary

  with semiconductor devices and specially adapted for lamps without electrodes in the vessel, e.g. surface discharge lamps, electrodeless discharge lamps · CPC title

• H05B41/16 Primary

  in which the lamp is fed by DC or by low-frequency AC, e.g. by 50 cycles/sec AC {, or with network frequencies} · CPC title

• H01J65/048

  the field being produced by using an excitation coil · CPC title

• Y02B20/00

  Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps · CPC title