Apparatus and method for starting a fluorescent lamp

A method of starting a fluorescent lamp coupled to the secondary of a transformer, comprising:

• sensing that no current is flowing through the lamp;
• applying a series of pulses to a primary of the transformer at a pulse repetition frequency, the series of pulses causing the secondary of the transformer to have an output voltage, said pulse repetition frequency having an initial pulse repetition frequency;
• sweeping the pulse repetition frequency of the series of pulses from said initial pulse repetition frequency up to a higher pulse repetition frequency while sensing for current through the lamp;
• and
• when current is sensed in the lamp, maintaining the pulse repetition frequency at the initial pulse repetition frequency.

A method of starting a fluorescent lamp comprising:

• applying a signal at a first frequency to a primary of a transformer to generate a first voltage at a secondary of said transformer;
• sweeping said signal to a second frequency, said second frequency generating a second voltage at said secondary which is greater than said first voltage;
• and
• decreasing said signal to a frequency below said second frequency in response to a current in a fluorescent lamp.

An apparatus for driving a fluorescent lamp, comprising:

• a transformer having a primary and a secondary, said primary in communication with an input signal, said secondary configured to generate a voltage in response to a frequency of said input signal;
• a sensor which is configured to generate an output indicative of whether current is flowing in a fluorescent lamp;
• and
• a control circuit in communication with said sensor, said control circuit configured to periodically sweep the frequency of said input signal when said sensor does not indicate current is flowing, said control circuit further configured to decrease said frequency of said input signal when said sensor indicates that current is flowing.

An apparatus for driving a fluorescent lamp, comprising:

• a transformer means having a primary and a secondary, said primary in communication with an input signal, said secondary configured to generate a voltage in response to the frequency of said input signal;
• a sensor means for generating an output indicative of whether current is flowing in a fluorescent lamp;
• and
• a control means in communication with said sensor means for sweeping the frequency of said input signal when said sensor means does not indicate current is flowing, said for decreasing said frequency of said input signal when said sensor means indicates that current is flowing.