Ballast circuit for compact fluorescent lamp

Fluorescent lamp apparatus for connection to an AC input voltage and to at least one fluorescent lamp, said lamp apparatus comprising

• rectification means for generating a rectified voltage responsive to said AC input voltage,
• voltage amplification means for amplifying said rectified voltage, and
• ballast circuit means in circuit with said rectification means and said voltage amplification means and arranged for connection with the lamp for applying power variably thereto, said ballast circuit means including
• resonant circuit means for generating a high frequency voltage in response to said rectified voltage, and
• voltage feedback means, in electrical communication with said resonant circuit means and said rectification means, for generating a selected high frequency voltage signal, whereby said high frequency voltage signal is superimposed over said AC input voltage.

Ballast circuit apparatus for connection with a dimmable compact fluorescent lamp mounting one or more fluorescent lamps and for connection with an AC input voltage, said circuit apparatus comprising

• rectification means for rectifying said AC input voltage,
• first and second semiconductor switching means in electrical communication with said rectification means and each having a selected normal conduction interval, wherein said normal conduction interval of said first switching means is substantially opposite to that of said second switching means,
• a series resonant circuit in circuit with said rectification means and said first and second switching means for generating a high frequency voltage in response to said input voltage,
• voltage feedback means in circuit with said resonant circuit for feeding back to said rectification means said selected high frequency voltage at a selected elevated voltage level at least substantially equal to said input voltage,
• circuit starter means in electrical communication with one of said first and second switching means for selectively actuating said switching means, and
• dimming control means in electrical communication with at least one of said first and second switching means for adjusting variably said brightness level of the lamp.