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This is the principle of fluorescent

Fluorescent tube is filled with the low-pressure boxargon gas or an argon-neon mixed gas and mercury vapor, and the inside surface of the glass of the fluorescent tube, is coated with a layer of phosphorus fluorescent paint, at both ends of danna520the lamp has a filament made of tungstencoil. When the power is turned on, the current through the filament heating and the release of the electron, the electron will pipe the gas into a plasma (plasma), and to make the tube current to increase, the lamp began to produce betweenlaodie20 the two sets of filament voltage exceeds a certain value discharge, the mercury vapor release a 253.7nm and 185nm wavelengths of ultraviolet light, the phosphorus on the surface of the inside of the fluorescent tube fluorescent paint will absorb ultraviolet light, and the release ofbox the longer wavelengths of visible light.

The color of light is controlled by the proportion of the phosphorus composition, the glass tube is to avoid the harmful ultraviolet rays and other harmful substances such as mercury leak out.

The discharge current of the fluorescent tube and the conduction resistance between a positive feedback relationship: when morelaoma20 current flows into the fluorescent tube so that more gas is ionized, so that the conduction resistance within the tube to continue to reduce, and so would cause more current into the fluorescent tube. If the fluorescent tube connected directly to a fixed voltage power supply, the fluorescent tube will rise due to the current and soon to be burned, an auxiliary circuit therefore need to control the current into the fluorescent tube at a fixed level, while the current control circuit is usually called ballast.

Ballast is actually an inductor, when the conduction resistance to a very low, fixed ballast inductance and copper consumption approximates the given value, the conduction current to begin to stabilize work.

Traditional ballast required with small components to the pressure difference between the filament to the extent sufficient to discharge the fluorescent tube called a starter (Starter, commonly known as "Topstar he", "jump bubble"), the latest electronic ballast No starter, start the work has been included in the ballast.

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