Dimmable self-ballasted fluorescent lamp and discharge lamp operating apparatus
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsSatoshi Kominami, Kenichiro Takahashi, Koji Miyazaki, Yoji Tashiro, Tetsuya Tahara
Life of this patent
Estimating the term…
Abstract
A dimmable self-ballasted fluorescent lamp includes a fluorescent lamp, a ballast and a lamp base that are formed as one unit. The ballast includes a preheating current supply circuit for supplying a preheating current to the fluorescent lamp; an inverter circuit portion for supplying a high frequency AC voltage to the fluorescent lamp; and a control circuit portion for controlling a driving frequency of the inverter circuit portion. The ballast is provided with an output current limiting element for limiting an output current from the preheating current supply circuit.
Claims7
A dimmable self-ballasted fluorescent lamp obtained by forming a fluorescent lamp, a ballast that is electrically connected to the fluorescent lamp and a lamp base as one unit,
- the ballast comprising:
- a preheating current supply circuit for supplying a preheating current to the fluorescent lamp;
- an inverter circuit portion for supplying a high frequency AC power to the fluorescent lamp;
- and
- a control circuit portion for controlling a driving frequency of the inverter circuit portion,
- wherein the ballast is provided with an output current limiting element for limiting an output current from the preheating current supply circuit;
- wherein
- the output current limiting element is constituted with a circuit element that becomes in an open state when an output current flows at a predetermined value or more, and
- the circuit element is a capacitive element or an inductive element.
A dimmable self-ballasted fluorescent lamp comprising:
- a preheating current supply circuit for supplying a preheating current to the fluorescent lamp;
- an inverter circuit portion for supplying a high frequency AC power to the fluorescent lamp;
- a control circuit portion for controlling a driving frequency of the inverter circuit portion;
- and
- an output current limiting element for limiting an output current from the preheating current supply circuit, wherein
- the output current limiting element includes a circuit element that becomes in an open state when an output current flows at a predetermined value or more.
Dependencies are inferred from the claim text.