The working principle of fluorescent lamps
The working principle is: when the switch is turned on, the power supply voltage is immediately applied to the two poles of the starter through the ballast and the lamp filament. A voltage of 220 volts immediately ionizes the inert gas of the starter, creating a glow discharge. The heat of the glow discharge causes the bimetal to expand and the poles come into contact. The current passes through the ballast, the starter contacts and the filaments at both ends to form a path. The filament is quickly heated by the current, emitting a large number of electrons.
At this time, since the two poles of the starter are closed, the voltage between the two poles is zero, the glow discharge disappears, and the temperature in the tube decreases; the bimetal is automatically reset, and the two poles are disconnected. At the moment when the two poles are disconnected, the circuit current is suddenly cut off, and the ballast generates a large self-inductive electromotive force, which acts on both ends of the tube after being superimposed with the power supply voltage. When the filament is heated, a large number of electrons are emitted from the low-potential end to the high-potential end at a great speed under the action of the high voltage at both ends of the lamp tube.
In the process of accelerating motion, the argon gas molecules in the collision tube are rapidly ionized. The ionization of argon generates heat, and the heat causes mercury to produce vapor, which is then ionized and emits strong ultraviolet rays. Under the excitation of ultraviolet light, the phosphor in the tube wall emits almost white visible light.
After the fluorescent light is illuminated normally. Since the alternating current continuously passes through the coil of the ballast, a self-induced electromotive force is generated in the coil, and the self-induced electromotive force hinders the current change in the coil. At this time, the ballast acts as a step-down current limiter to stabilize the current within the rated current range of the lamp. The voltage at both ends of the lamp is also stable within the rated working voltage range. Since this voltage is lower than the ionization voltage of the starter, the starter connected in parallel at both ends will no longer work.
Is LED fluorescent lamp the same as ordinary fluorescent lamp?
1. Ordinary fluorescent lamp: There is a filament at each end of the fluorescent lamp, and the lamp The tube is filled with a small amount of argon and thin mercury vapor, and the inner wall of the lamp tube is coated with fluorescent powder. The gas between the two filaments emits ultraviolet rays when conducting electricity, so that the fluorescent powder emits soft visible light.
The working characteristics of ordinary fluorescent lamps: a high voltage is required when the lamp begins to ignite, and only a small current is allowed to pass through during normal lighting. At this time, the voltage at both ends of the lamp is lower than the power supply voltage.
2. LED fluorescent tube: LED fluorescent lamp is mainly characterized by high quality, durability and energy saving, and the projection angle adjustment range is large. The brightness of 15W is equivalent to ordinary 40W fluorescent lamp. High temperature resistance, moisture-proof and waterproof, anti-leakage. Use voltage: 110V, 220V optional, cover optional glass or PC material. The lamp head is the same as the ordinary fluorescent lamp.
LED fluorescent tube adopts the latest LED light source technology, digital appearance design, saves electricity by more than 70%, 12W LED fluorescent light is equivalent to 40W fluorescent tube (used for ballast and starter) The real power consumption of a 36W fluorescent lamp is 42W to 44W). The life of LED fluorescent lamps is more than 10 times that of ordinary lamps, almost maintenance-free, and there is no need to frequently replace lamps, ballasts, and starters. The green and environment-friendly semiconductor electric light source has soft light and pure spectrum, which is beneficial to the user’s vision protection and physical health. The 6000K cold light source gives people a visually cool feeling, and the humanized illumination difference design is more conducive to concentration and efficiency.
3. Advantages of LED fluorescent tube:
1. Energy saving, 16W is equivalent to 40W brightness of ordinary fluorescent lamp, and the energy saving rate is more than 60%.
2. Long service life, 50000H hours can be used normally, 3 years warranty.
3. Good applicability, due to the small size of a single LED, it can be made into any shape.
4. The response time is short, which is the response time of the ns (nanosecond) level, while the response time of ordinary lamps is the response time of the ms (millisecond) level.
5. Environmental protection, no harmful metals, easy recycling of waste.
6. Brilliant colors, pure luminous color, narrow spectral range, and can be mixed into colorful or white light by red, green and blue three primary colors.
Precautions for the use of LED fluorescent tubes
LED fluorescent tubes must be waterproofed to prevent humid air from entering and being difficult to discharge, which may corrode the electrical components inside for a long time , may also cause a short circuit, damage the electrical components inside, or cause a fire.
