LED fluorescent tubes
have been popular for many years. Although they are used in modern home decoration, many old houses and office spaces will still choose them for lighting. If the amount of use is large, some failures will occur, such as the problem of the lamp not lighting up. With the advantages of energy saving, environmental protection and pollution-free LED, LED fluorescent tubes are favored by consumers in the industry. Let's take a look at the reasons why the LED fluorescent tube does not light up?
First, the structure and function of fluorescent tubes
There is a filament at each end of the fluorescent lamp. The lamp tube is filled with a small amount of argon and dilute mercury vapor. The inner wall of the lamp tube is coated with phosphor powder. The gas between the two filaments emits ultraviolet rays when conducting electricity, so that the phosphor powder emits soft visible light.
2. Ballasts, starters and discharge tubes of fluorescent tubes
The inductive ballast is an iron-core inductive coil. The nature of the inductance is that when the current in the coil changes, the magnetic flux will change in the coil, thereby generating an induced electromotive force whose direction is opposite to the direction of the current, thus hindering the changes in current.
The starter acts as a switch in the circuit. It is composed of a neon gas discharge tube and a capacitor in parallel. The function of the capacitor is to eliminate the electromagnetic interference to the power supply and form an oscillation circuit with the ballast to increase the amplitude of the starting pulse voltage.
One electrode in the discharge tube is composed of a bimetallic sheet, which is heated by neon bulb discharge, so that when the bimetallic sheet is opened and closed, the current of the inductive ballast is abruptly changed and a high-voltage pulse is generated to be applied to both ends of the lamp tube. LED lamp drive power supply
3. 10 reasons why the fluorescent tube is not bright
1. Both ends of the fluorescent tube light up, but the tube cannot be lit normally: mostly because the temperature is too low, which is common in winter; in addition, the power supply voltage is too low;
2. After the lamp is illuminated, the light rotates in the tube, commonly known as the rolling dragon: this is a temporary phenomenon that is often common in new tubes or the contact is not good.
3. The lamp can not emit light: it may be due to poor contact, damaged starter, broken filament, switch replacement, broken lamp cap, and broken ballast.
4. The lamp can be bright but the light is flickering: the quality of the lamp is not good.
5. The brightness of the lamp tube is reduced: the lamp tube is aging (the ends of the lamp tube are black).
6. Both ends of the lamp tube are black: the lamp tube is aging and needs to be replaced.
7. Black spots appear at both ends of the lamp: the mercury condenses in the lamp, and it is normal for it to evaporate and disappear after starting.
8. Larger electromagnetic sound: the quality of the ballast is poor, and the vibration of the silicon steel sheet is large.
9. Ballast overheating or smoking: poor ventilation and heat dissipation or short circuit between turns of the internal coil.
10. Pull the switch, and the lamp will turn off immediately after it flashes: this may be a wiring error and the filament will be blown.