How to judge the quality of ballast for fluorescen

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Fluorescent lamp ballasts are electronic ballasts. Electronic ballast, a kind of ballast, refers to the electronic equipment that uses electronic technology to drive the electric light source to produce the required lighting. The corresponding is inductive ballast (or ballast). More and more modern fluorescent lamps use electronic ballasts, which are light and compact, and can even integrate electronic ballasts with lamps. At the same time, electronic ballasts can usually have the function of starters, so separate starters can be omitted

since Edison invented the lamp, we began to use it in every household. From the water fire lamp to the small electric bulb in the 60s, the lamp revolution is constantly going on, and behind it, it has developed into a lamp tube, fluorescent lamp, etc. Compared with other lamps, fluorescent lamps have higher brightness, and they need to save electricity. Therefore, for us, they are basically used in every family. In fact, there is a reason why fluorescent lamps will glow, and the ballast plays a very important role. So, how to judge the quality of ballast? What is the maintenance method of fluorescent lamp ballast? Fluorescent lamp is the best helper to improve the atmosphere in family life. If there is a problem, the first thing we think of must be that the lamp tube is broken. In fact, the ballast at both ends of the lamp is also a frequent problem. Today, I'll show you some knowledge about the maintenance of fluorescent lamp ballast

fluorescent lamp ballast structure

internal structure of ballast:

fuse, rectifier diode (4, for AC/DC conversion), fast recovery diode (3, triode bias, trigger off), trigger diode (high-frequency signal generation), high-voltage power triode (2, high-frequency switching power amplifier), filter electrolytic capacitor (DC power filter), high-voltage capacitor (impedance matching), low-voltage capacitor (forming trigger power with resistance) Lighting capacitor (connected in parallel with the lamp tube to generate lighting voltage), feedback coil (magnetic ring, wound oscillation coil), inductance (matched as high-frequency output), small resistance (4, respectively for charging, triode bias, impedance matching)

fixed structure of ballast:

the ballast is arranged on the support shell, the two ends of the ballast shell are provided with fixed slots, the corresponding fixed slot position on the support shell is provided with a strip-shaped locking slot, a soft clamping seat is arranged on the fixed slot of the ballast shell, the lower end of the clamping seat is provided with an extended clamping part, which passes through the fixed slot and the strip-shaped locking slot, and the clamping part is also provided with a concave bayonet that can clamp the inner edge of the strip-shaped locking slot

when fixing the ballast, first place the clamping part at the lower end of the software clamping base corresponding to the fixed slot and the strip lock slot, then pass the clamping part through the fixed slot and the strip lock slot, and then rotate the clamping base at a certain angle. The clamping base uses the concave bayonet on the clamping part to clamp the inner edge of the strip lock slot, that is, fix the ballast on the support shell

The ballast fixing structure has the advantages of simple and reasonable structure and convenient installation and disassembly of ballast

fluorescent lamp ballast voltage

the function of the ballast is to superimpose the self induced voltage generated at the moment when the bubble jump (starter) contact is disconnected on the 220V mains to excite the mercury vapor ionization conductive luminescence in the lamp. Once the lamp is normally illuminated, the ballast is equivalent to an inductance connected in series in the circuit That is, the lamp tube and ballast are connected in series to the 220V mains At this time, the working voltage of the lamp is determined by the ratio of the ballast and the lamp on the 220V power supply

working principle of ballast

when the switch is turned on, the power supply voltage is immediately added to the two poles of the starter through the ballast and the lamp filament. The voltage of 220 volts immediately ionizes the inert gas of the starter and generates glow discharge. The heat of this process makes the bimetallic sheet expand by heating. Because the expansion degree of the dynamic and static contact sheets is different, the U-shaped dynamic contact sheets expand and stretch, and contact with the static contact sheets to connect the circuit, so the two poles of the ballast contact. Current passes through ballast, starter contact and filaments at both ends to form a path. At this time, because the two poles of the starter are closed, the voltage between the two poles is zero, the neon in the starter stops conducting, and the glow discharge disappears, resulting in the temperature drop in the tube, the cooling and contraction of the U-shaped moving contact, the separation of the two contacts, and the automatic disconnection of the circuit

how to distinguish the quality of ballast

1. Look at the appearance. If the ballast is burned out, the shell will be black

2. Electric pen detection, there are shells at the incoming and outgoing ends

no power at the incoming end indicates that the ballast is broken, resulting in a fuse short circuit at the incoming end

power at the incoming end and no power at the outgoing end indicates that the ballast is internally open circuit

if the shell is charged, it indicates that the ballast has leakage

3. If both the incoming and outgoing lines are charged, the shell is not charged, and the light is not on, it can also be judged by replacing the trigger. If the trigger is changed and the light is not on, the ballast is broken

how to judge the quality of ballasts

1. According to international standards, ballasts that reach 20% brightness in 1 second and more than 80% brightness in 4 seconds are good ballasts, while those that reach 80% brightness in an instant or fail to reach the standard brightness in 4 seconds are of poor quality

2. It's old-fashioned wire wound. It's better to use a multimeter. You can use the 200 gear of European parent gear (resistance gear)! Measure two terminals with a probe

3. The output of electronic ballast has four wires, two of which are connected in series at both ends of a capacitor, and the other two are voltage output terminals. If there is no high-frequency AC voltage output at the voltage output terminal, there is a fault. The common faults of electronic ballasts are generally the damage of the oscillating tube, the damage of the primary vibration capacitor, and the leakage of the filter capacitor

fluorescent lamp ballast maintenance

the fluorescent lamp is broken, which is likely to be the damage of the electronic ballast. Because the rectifier filter electrolytic capacitor in the electronic ballast is easy to breakdown, because the capacitor breakdown will cause a chain reaction, causing the breakdown of rectifier diodes and power amplifier tubes, so it will make a sound and have a burning smell. Generally, there is no sound when the inductive ballast is damaged, only the scorching smell is generated. It is better to replace the ballast with a new one

before replacing the ballast with a new one, you can try restarting the ballast: plug and unplug the ballast wiring again, and choose one of the live line and zero line. If it has to be replaced, the ballast of household fluorescent tubes is usually in the lamp cap. Pry open the lamp cap, and we can see a small integrated circuit block, that's it. We need to cut off the integrated circuit blocks at both ends of the lamp cap and keep the terminals from both ends of the lamp

editor's summary: after knowing the maintenance method of ballast, I would like to remind you again carefully that if you want to replace it yourself, remember to cut off the power first!! Do a good job of safety protection. Don't do it easily before figuring out how to replace it, so as not to cause personal injury if the lamp is not replaced properly. As the saying goes: take precautions before it happens. At the beginning of decoration, it is better to use well-known brands of materials. First, the products of the brands have quality assurance, but in case of problems in the future and need to be repaired and replaced, accessories of the same model are easier to buy in the market





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