What is the function of a fluorescent lamp starter?

There's a bit of a problem here!

Fluorescent lamp starters, commonly known as bubble jumpers, have two types: glow type and thermal switch type. The most commonly used is the glow type. The outside is an aluminum (or plastic) shell with a neon lamp and a paper capacitor, the neon lamp is a small glass bubble filled with neon gas, and inside there is a U-shaped bimetal sheet and a static contact piece.

The bimetal sheet is composed of two metals with different expansion coefficients, and after heating, the degree of bending decreases due to the different expansion of the two metals, and it comes into contact with the static contact, and after cooling, it returns to its original shape and separates from the static contact.

A 0 005 microfara capacitor is connected in parallel between the two contacts, and its function is to eliminate the influence of sparks on telecommunication equipment, and form an oscillation circuit with the ballast, delay the filament preheating time, and facilitate the fluorescent lamp to shine.

The compensation capacitor needs to be installed separately, and it needs to be about 10uf.

Fluorescent lamp, in the initial stage of igniting the lamp, needs a high-voltage pulse of more than 400V, once the lamp is ignited, the voltage to maintain normal operation is only about 60 90V, and the power supply is AC220V, so it is necessary to use a ballast and a starter to provide a high-voltage pulse when the lamp is lit, and the ballast shares a part of the voltage during normal operation.

The starter is mainly composed of bimetal sheets, the gap between the contact points is small, and when the circuit is turned on, the supply voltage is enough to cause a glow discharge through the filling gas. Due to the different thermal expansion of the two metals, the slowly heated contact pieces produce relative bending, and after a second or two, when the contact pieces touch each other, a series circuit is formed through the ballast and the filament, so that a fairly strong current (preheating current) heats the filament rapidly. After the metal sheet is contacted, the glow discharge is extinguished, the metal sheet begins to cool, the contact point pops open, and the series circuit is interrupted, because it is a high inductance circuit, so within 1ms, a high-voltage pulse is generated between the two filaments of the lamp, and the lamp is ignited.

1. The starter is a glass bubble filled with argon, there is a pair of contacts inside, one is a fixed static contact, and the other is an inverted U-shaped moving contact made of bimetals with different expansion coefficients. After the collision, due to the disappearance of the gap between the sheets, the starter is no longer discharged, and the bimetal sheet cools down and returns to its original position, and a certain gap is still maintained between the contacts.

2. The ignition process of the fluorescent tube: when the power supply is turned on, the power supply voltage is added to the starter through the filament at both ends of the ballast and the lamp, causing glow discharge, so that the two contacts of the starter touch each other to form a path, and the current passes through this path to heat the filament in the lamp. At this time, the glow discharge disappears due to the contact action of the starter, and the bimetal sheet is disconnected due to cooling, causing the current in the circuit to be abruptly interrupted.

At this time, a high voltage is generated at both ends of the ballast, which is superimposed with the power supply and added to both ends of the lamp, so that the gas in the lamp is ionized and discharged, and the fluorescent lamp is lit. After the fluorescent lamp is lit, the voltage at both ends of the lamp drops down, about 80-120 volts, so that the low voltage does not cause the starter to shine again. So, after the fluorescent lamp is lit, the starter does not work.

Fluorescent lamps without starters are LED fluorescent lamps. LED fluorescent lamp is divided into two kinds of built-in power supply and external power, when the built-in LED fluorescent lamp is installed, the original fluorescent lamp is removed and replaced with LED fluorescent lamp, and the ballast and brightener are removed, so that the 220V AC mains can be directly added to both ends of the LED fluorescent lamp.

Compared with incandescent lamps, LED fluorescent lamps save more than 80% of electricity, and the life span is more than 10 times that of ordinary lamps, which is almost maintenance-free, and there is no problem of frequent replacement of lamps, ballasts, and sheds. Green and environmentally friendly semiconductor light source with soft light.

The principle of fluorescent lamp startup is that 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. A voltage of 220 volts immediately ionizes the inert gas of the starter, producing a glow discharge.

When the switch is closed and the power supply is turned on, the lamp has not yet been discharged, and the power supply voltage is added to the two bimetallic contacts in the starter through the filament, so that the neon tube produces glow discharge and heating, and the two contacts are turned on, so the current passes through the filament at both ends of the ballast and the lamp, so that the filament heats up and emits electrons.

At this time, the neon tube is short-circuited by the bimetallic contact to stop the glow discharge, and the bimetallic contact is also separated due to the decrease in temperature, and at this moment, the ballast generates a fairly high self-induced electromotive force. It is connected in series with the power supply voltage and added to both ends of the lamp to cause fox discharge, so that the fluorescent lamp is lit.

The function of the starter is to produce a momentary self-inductive high pressure to penetrate the gas inside the lamp (a low-pressure inert gas containing mercury vapor) after the fluorescent lamp is preheated, so that the lamp can be activated.

The starter provides high-voltage pulses when the lamp is lit, and the ballast shares a part of the voltage during normal operation. Or laugh.

Instantaneous ionization stage of the starter.

At the moment when the poles are disconnected, the circuit current is suddenly cut off, and the ballast generates a large self-induced electromotive force, which acts on both ends of the tube after superimposing with the power supply voltage. A large number of electrons emitted by the filament when heated move from the low potential end to the high potential end at great speed under the action of high voltage at both ends of the lamp. In the process of accelerating motion, the argon molecules in the tube collide, causing them to ionize rapidly.

Argon ionizes to generate heat, and the heat causes the mercury to produce vapor, which is then ionized and emits intense ultraviolet light. When excited by ultraviolet light, the phosphors inside the tube wall emit near-white visible light. After the fluorescent lamp glows normally.

Because the alternating current continuously passes through the coil of the ballast, the self-induced electromotive force is generated in the coil, and the self-induced electromotive force hinders the current change in the coil, so that the ballast takes off and lowers the current limit, so that the current is stabilized within the rated current range of the lamp, and the voltage at both ends of the lamp is also stabilized within the rated working voltage range. Since this voltage is lower than the ionization voltage (induced electromotive force) of the starter, the starter connected in parallel at both ends no longer functions and is automatically disconnected.