The working principle of the inductive ballast, the principle of the action of the ballast

When the AC power supply of 220V50Hz is applied to the switch and close circuit, the current flows through the ballast, the lamp filament, and the starter to heat the filament (the starter is disconnected at the beginning, due to the application of an AC voltage greater than 180V, the gas glow discharge in the jump bubble of the starter, and the bimetal sheet in the jump bubble is heated and expands and deforms, and the two electrodes are close together to form a path to heat the filament). When the two electrodes of the starter are close together, because there is no arc discharge, the bimetal sheet is cooled, and the two electrodes are disconnected, because the inductive ballast is inductive, when the two electrodes are disconnected, the current in the circuit suddenly disappears, so the ballast produces a high pulse voltage, which is superimposed with the power supply voltage and added to both ends of the lamp, so that the inert gas in the lamp ionizes and causes arc discharge. (The high impulse voltage time is about 1ms 600v 1500v, and its exact voltage value depends on the type of lamp).

During normal luminescence, the self-inductance of the ballast plays a role in stabilizing the current in the circuit. Inductance ballast is an iron core inductance coil, the nature of the inductance is that when the current in the coil changes, the ** circle will cause a change in magnetic flux, thereby generating an induced electromotive force, which is in the opposite direction of the change of current, thus hindering the change of current, so as to limit and stabilize the current.

Inductive ballast is an iron core inductance coil, the nature of the inductance is that when the current in the coil changes, the ** circle will cause a change in magnetic flux, resulting in an induced electromotive force, which is in the opposite direction to the direction of the current, thus hindering the current change.

The working principle of the electronic ballast: 220 volt electric rectification into DC, and then filter the lower wave, and then the OTL oscillation circuit composed of two transistors will turn DC into high-frequency AC and boost, get a 300+V AC 1000+V peak, 30-80kHz or so high-frequency and high-voltage electricity is added to both ends of the lamp, and the light is on. (It is to rectify the voltage and then form a high-frequency alternating current through the oscillation circuit, and the voltage is boosted by the transformer to make the fluorescent lamp shine.)

The working principle of inductive ballast: The equipment that starts and limits the current on the fluorescent lamp and generates instantaneous high voltage should be called a ballast, which is made of enameled wire wrapped on the iron core made of silicon steel, and such a coil with an iron core will induce high voltage when the power is off instantaneously, and it will be added to the electrodes (filaments) at both ends of the fluorescent tube. This action is carried out alternately, when the starter (jumping bubble) is closed, the filament of the lamp is turned on and heated by the current limiting of the ballast; When the starter is open, the ballast will induce high pressure to be added to the filament at both ends of the lamp, and the filament emits electrons to bombard the fluorescent powder on the wall of the tube.

When the lamp emits light normally, the internal resistance becomes smaller, and the starter always maintains an open circuit state, so that the current can stably pass through the lamp and the ballast, so that the lamp emits light normally. Because the ballast always has a current passing through when the fluorescent lamp is working, it is easy to vibrate and heat, so the fluorescent lamp with ballast, especially when the quality of the ballast is not good, will produce a loud sound, and it is easy to burn out after a long time.

Working characteristics of fluorescent lamp: a high voltage is required when the lamp starts to ignite, and only a small current is allowed to pass through when the light is emitted normally, and the voltage at both ends of the lamp is lower than the power supply voltage.

The emitter plays a switching role in the circuit, which is formed by a neon discharge tube and a capacitor in parallel, and the role of the capacitor is to eliminate the electromagnetic interference of the power supply and form an oscillation circuit with the ballast to increase the amplitude of the starting pulse voltage. One of the electrodes in the discharge tube is composed of a bimetal sheet, which is heated by neon bubble discharge, so that when the bimetal sheet is opened and closed, the current of the inductance ballast is abruptly changed and a high-voltage pulse is generated and added to both ends of the lamp.

After the fluorescent lamp is connected to the circuit, the glow discharge begins between the two electrodes of the igniter, so that the bimetal sheet is heated and expands and contacts with the static contact pole, so the power supply, the ballast, the filament and the radiator form a closed loop, the current preheats the filament, when the heating time is 1-3 seconds, the glow discharge between the two electrodes of the ignitor is extinguished, and then the bimetal sheet is cooled and disconnected from the static contact pole, when the two electrodes are disconnected, the current in the circuit suddenly disappears, so the ballast produces a high-voltage pulse, which is superimposed with the power supply. It is added to both ends of the lamp to ionize the inert gas in the lamp and cause arc discharge, and the self-inductance of the ballast also plays a role in stabilizing the current in the circuit during the normal luminescence process.

The inductive ballast of the iron core is not "one drag two", and it cannot drive two lamps. Two lamps in series, absolutely not. If it is "one drag two", it should be one incoming line and two outgoing lines. The two outgoing wires are connected to two lamp feet respectively.

Ordinary inductor ballast, one-to-two circuit diagram.

This circuit is entered through the live wire to the ballast, then to the filament on the right side of the tube on the right, and then to the starter of the tube on the right. The zero line passes through the filament of the left tube to the starter of the left tube, and the filament of the left and right tubes has one end of the filament in series. At this time, the two starters start to discharge and heat, and when the starter is disconnected, the self-induced electromotive force generates a high-voltage lighting lamp and limits the current after heating.

In general, it is a series of two lamps with two starters.

First, the nature is different.

1. Inductive ballast: an iron core inductance coil, the property of inductance is that when the current in the coil changes, it will cause a change in the magnetic flux in the coil, so as to produce an induced electromotive force in the opposite direction of the current, thereby hindering the change of current.

2. Electronic ballast: A kind of ballast, which refers to the electronic equipment that uses electronic technology to drive the electric light source to produce the required lighting.

Second, the working principle is different.

1. Inductive ballast: When a 220V50Hz AC power supply is applied in the switch closing circuit, the current flows through the ballast, filament and starter heating filament (the starter is disconnected at the beginning because the applied AC voltage is greater than 180V, and the gas will glow.

2. Electronic ballast: because the gas discharge lamp (such as fluorescent lamp, neon lamp, metal halide lamp, etc.) is a negative resistance light source with V-I characteristics, that is, a negative value, when the lamp current rises, the working voltage of the lamp drops, but the power supply voltage will not drop, and the extra voltage will further increase the lamp current after being added to the lamp.

Basic classification. By installation mode.

1) Freestanding.

2) Built-in type.

3) Monolithic.

By performance characteristics.

1) Ordinary type, high frequency makes it small, light and has the function of saving electricity;

2) High power factor type H-level, using passive filtering and abnormal protection;

3) L-level high-performance electronic ballast, with perfect abnormal protection function, electromagnetic compatibility;

4) Cost-effective electronic ballast L-level, integrated technology and constant power circuit design, low impact of voltage fluctuation on illumination;

5) Dimmable electronic ballast, using integrated technology and active variable frequency resonance technology.

Let's talk about the work of the lamp first, the fluorescent lamp mainly relies on gas ionization to emit light, and it needs high voltage when ignited, and the working voltage is between 100-200V, and the voltage is too large to burn out. The function of the inductive ballast is to use the inductance to generate high voltage at both ends of the lamp when the lamp is turned on, and the inductive ballast is divided and limited to prevent the lamp from burning after the lamp works, and the electronic ballast is made of a circuit similar to a constant current source through electronic components, when the lamp is ignited, because the gas resistance is very large before the lamp is ignited, the current flows through and generates high voltage, and the constant current is maintained after ignition, and the lamp is protected to limit its current.

Electronic ballast is an upgraded product of inductive ballast, electronic ballast should be called high-frequency electronic ballast, which is to convert the electronic circuit into a high-frequency current of more than 20000Hz after rectifying the 50Hz mains to light up the fluorescent tube. It has the advantages of light weight, less heat, high efficiency, no Weng Weng sound, and no flicker when lit.

The electronic ballast saves power, and the inductive ballast consumes electricity; The sound is low when the electronic ballast is used, and the sound is loud when the inductive ballast is used; The electronic ballast is not affected by voltage fluctuations, and the inductive ballast is subject to voltage fluctuations obviously, and will not work; Electronic ballasts do not need a starter when they are used, and inductive ballasts need a starter;

Structural differences:

The structure of the inductive ballast is very simple, that is, a coil wrapped around the iron core, while inside the electronic ballast is a circuit board. Electronic ballasts can be connected directly to the lamp, while inductive ballasts require the installation of a starter (bubble jump) before they can be used.

Differences in principle:

When the inductance ballast is energized, the starter works, and the current flows through the ballast-filament 1-starter-filament 2 to form a loop, so that the filament is preheated and the bimetal sheet inside the starter is heated, and the temperature of the bimetal sheet reaches a certain value after a few seconds, and the deformation occurs, the starter first short-circuits and then breaks the circuit, and the current in the circuit decreases sharply at the moment of breaking, so that the inductance ballast produces a huge self-inductive voltage (thousands of volts) to penetrate the gas inside the lamp, so that the lamp starts. After the lamp is activated, the tube voltage drop drops rapidly, the starter no longer works, and the inductive ballast becomes a "resistor" of the series lamps (in fact, it uses the inductive reactance of the inductor) to limit the current of the lamp.

After the electronic ballast is energized, the half-bridge inverter circuit composed of two high-power transistors, a magnetic ring transformer and a number of other components begins to work, continuously oscillates at high frequency and outputs high-frequency current, and the final circuit of the electronic ballast is that the high-frequency current first passes through a (choke) small inductor, then through the filament 1, then connects a polyester capacitor, and then flows through the filament 2, and then flows back. Among them, the series structure of the choke and the capacitor constitutes a series resonant circuit, when the high-frequency current flows and the series resonance occurs, the terminal voltage of the capacitor and inductor will increase significantly, much higher than the input value, and the electronic ballast uses this principle to generate a starting high voltage to make the lamp glow, without using a starter. When the lamp is activated, the ballast is output to the lamp in the form of a constant current, which continuously lights up.

Sensory differences:

An inductive ballast has an iron core coil inside it, so it is heavier, while an electronic ballast has only one circuit board inside it, which is lighter in weight and is usually a plastic case.

From the circuit point of view: 1. The inductive ballast adopts a large power frequency inductor and a starter, and the inductor cooperates with the starter to generate high voltage to light the lamp at the moment of power-on, and then the starter stops working, and the inductor plays the role of current limiting. The electronic ballasts commonly used now directly use the principle of switching power supply to produce high-voltage lighting lamps, and then there is also inductance current limiting, but because of the high frequency, this inductance is very small.

2. The inductive ballast circuit is simple, and the electronic type is more complex.

In terms of effect: 1. The electronic type is easy to start, and the voltage range is very wide. However, it is difficult to start the cavity rental source when the voltage of the inductive type is low.

2. The frequency of the electronic type is high, and the flash of the lamp cannot be felt, while the inductive type is the power frequency, which can feel the flicker.

3. The inductive ballast will make a noise when the inductive silicon steel sheet is loose, but there is no such problem when the electronic is loose.

4. The inductive type is more durable and not easy to break, and some products of the electronic type are not easy to break, especially the low-cost quality.

The electronic ballast is to rectify the power frequency alternating current full-bridge into DC and then light up the fluorescent lamp at high frequency through the ZCS zero-current switching circuit, and the inductor plays the role of current limiting, and uses the back electromotive force of the inductance to light the lamp.