Connection scheme for fluorescent lamps

Fluorescent lamps are connected in accordance with a slightly more complicated scheme in comparison with their nearest "relatives" - incandescent lamps. For the ignition of lamps of a luminescent type, starting devices must be included in the circuit, the quality of which directly affects the lifetime of the luminaires.

In order to understand the features of the circuits, it is first of all necessary to study the device and the mechanism of action of such devices.

Summary of the

Each of these devices is a sealed bulb filled with a special mixture of gases. At the same time, the mixture is designed in such a way that the amount of energy consumed by ionization of gases is much less than for ordinary incandescent lamps, which makes it possible to considerably save on illumination.

To ensure that the fluorescent lamp is constantly giving light, it must be supported by a glow discharge. To ensure this, the required voltage is applied to the electrodes of the light bulb. The main problem is that the discharge can appear only when a voltage is applied that is substantially higher than the operating voltage. However, this problem manufacturers of lamps have successfully solved.

The electrodes are installed on both sides of the fluorescent lamp. They take the voltage, through which the discharge is maintained. Each electrode has two contacts. A current source is connected to them, so that the space surrounding the electrode is heated.

Thus, the fluorescent lamp is ignited after heating its electrodes. To do this, they are exposed to a high-voltage pulse, and only then does the working voltage come into effect, the magnitude of which must be sufficient to maintain the discharge.

Luminous flux, lm	LED lamp, W	Contact fluorescent lamp, W	Incandescent lamp, W
50	1	4	20
100	5	25
100-200	6/7	30/35
300	4	8/9	40
400	10	50
500	6	11	60
600	7/8	14	65

Under the influence of discharge, the gas in the bulb begins to emit ultraviolet light, impervious to the human eye. To make the light visible to a person, the inner surface of the bulb is covered with a phosphor. This substance provides a shift in the frequency range of light into the visible spectrum. By changing the composition of the phosphor, the gamma of color temperatures also changes, which ensures a wide range of fluorescent lamps.

Luminescent type lamps, unlike simple incandescent lamps, can not simply be connected to an electrical network. For the appearance of the arc, as noted, the electrodes must warm up and an impulse voltage appear. These conditions are provided with the help of special ballasts. Ballasts of electromagnetic and electronic type were most widely used.

Classical connection via electromagnetic ballast

Schematic features

According to this scheme, a choke is connected to the circuit. Also in the composition of the scheme there must be a starter.

The latter is a low-power neon light source. The device is equipped with bimetallic contacts and is powered by an electrical network with variable current values. The throttle, starter contacts and electrode threads are connected in series.

Instead of a starter, a conventional button may be included in the circuit from an electrical call. In this case, the voltage will be supplied by holding the bell button in the pressed position. The button should be released after the ignition of the lamp.

The procedure for the electromagnetic ballast is as follows:

• after being connected to the mains, the choke starts accumulating electromagnetic energy;
• through the starter contacts provides the supply of electricity;
• current rushes along the tungsten filaments of heating the electrodes;
• electrodes and starter heat up;
• opens the starter contacts;
• the energy accumulated by the throttle is released;
• the voltage value on the electrodes varies;The
• fluorescent lamp gives light.

In order to increase the efficiency and reduce the noise that occurs during the lamp on, the circuit is equipped with two capacitors. One of them( the smaller one) is placed inside the starter. Its main function is to extinguish sparks and improve the neon pulse.

Among the key advantages of the scheme with electromagnetic ballast can be identified:

• reliability, time-tested;
• simplicity;
• affordable price.
• The disadvantages, as practice shows, more than benefits. Among their number it is necessary to allocate:
• impressive weight of the lighting device;
• long switch on time( average 3 seconds);
• low efficiency of the system during operation in the cold;
• comparatively high energy consumption;
• noisy throttle work;
• flickering, negatively affecting the eyesight.

Connection procedure

The connection of the lamp according to the diagram is performed with the use of starters. Next we will consider an example of installing one luminaire with the inclusion in the starter circuit model S10.This modern device has a non-flammable casing and a high-quality construction, which makes it the best in its niche.

The main tasks of the starter are as follows:

• ensuring the inclusion of the lamp;
• breakdown of the gas gap. For this purpose, the circuit breaks down after a fairly long heating of the lamp electrodes, which leads to the ejection of a powerful pulse and directly to the breakdown.

The throttle is used to perform the following tasks:

• current limit at the moment of electrode closure;
• generation of voltage sufficient for gas breakdown;
• maintaining the burning discharge at a constant stable level.

In this example, a 40 W lamp is connected. In this case, the choke must have a similar power. The power of the used starter is 4-65 W.

We connect according to the presented scheme. To do this, do the following.

The first step of the

In parallel, we connect the starter to the male side contacts at the output of the fluorescent lamp. These contacts represent the terminals of the filaments of the leakproof bulb.

The second step

For the remaining free contacts we connect the throttle.

Third step

Connect the capacitor to the supply terminals, again, in parallel. Thanks to the capacitor, the reactive power will be compensated and the interference in the network will decrease.

Connection via modern electronic ballast

Schematic features

Modern connection variant. The circuit incorporates electronic ballast - this economical and advanced device provides a much longer service life of fluorescent lamps compared to the above option.

In circuits with electronic ballast, fluorescent lamps operate at increased voltage( up to 133 kHz).Thanks to this, the light turns out to be smooth, without flicker.

Modern chips allow you to collect specialized launchers with low power consumption and compact size. This makes it possible to place the ballast directly in the lamp's base, which makes it possible to produce small-size lighting devices that are screwed into an ordinary cartridge, which is standard for incandescent lamps.

In this case, the chips not only provide the lamps with power, but also smoothly heat the electrodes, increasing their efficiency and increasing the service life. It is these fluorescent lamps that can be used in conjunction with dimmers - devices designed to smoothly adjust the brightness of light bulbs. The dimmer can not be connected to fluorescent lamps with electromagnetic ballasts.

By design, electronic ballast is an electrical voltage converter. A miniature inverter transforms direct current into high-frequency and alternating current. It is he who acts on the heaters of the electrodes. With increasing frequency, the intensity of heating the electrodes decreases.

The inverter is switched on in such a way that the frequency of the current is initially high. The fluorescent lamp, at the same time, is included in the circuit whose resonant frequency is much lower than the initial frequency of the converter.

Then the frequency starts to decrease gradually, and the voltage on the lamp and the oscillating circuit increases, due to which the circuit approaches the resonance. The intensity of heating the electrodes also increases. At some point, conditions are created sufficient to create a gas discharge, as a result of which the lamp begins to give light. The lighting device closes the circuit, the mode of operation of which varies.

When using electronic ballasts, the circuitry for connecting the lamps is composed in such a way that the adjusting device has the opportunity to adapt to the characteristics of the bulb. For example, after a certain period of use, fluorescent lamps require a higher voltage to create the initial discharge. Ballast can adapt to such changes and provide the necessary quality of lighting.

Thus, among the numerous advantages of modern electronic ballasts, the following points should be highlighted:

• high operating economy;
• careful heating of the electrodes of the lighting device;
• smooth switching on the light bulb;
• no flicker;
• possibility of use in low temperature conditions;
• self-adapting to the characteristics of the luminaire;
• high reliability;
• light weight and compact size;
• increase the life of lighting products.

Disadvantages of only 2:

• complicated connection scheme;
• higher requirements for proper installation and the quality of the components used.

Connection Procedure

All necessary connectors and wires usually come complete with electronic ballast. You can see the connection diagram on the picture. Also suitable schemes are given in the instructions for ballasts and direct lighting devices.

In this scheme, the lamp is included in 3 main stages, namely: the

• electrodes are warmed up, thereby ensuring a more gentle and smooth start-up and saving the life of the device;
• creates a powerful pulse, required for ignition;
• the value of the operating voltage is stabilized, after which the voltage is applied to the luminaire.

Modern connection schemes for lamps eliminate the need for a starter. Due to this, the risk of ballast burnout in case of start-up without a lamp installed is excluded.

Diagram for the serial connection of two lamps

Special attention should be paid to the connection of two fluorescent bulbs to one ballast. The devices are connected in series. To perform the work it is necessary to prepare:

• induction choke;
• starters in the number of two pieces;
• directly fluorescent lamps.

Connection sequence

First step. A starter is connected to each bulb. The connection is parallel. In this example, the starter is connected to the pin output from both ends of the lighting fixture.

The second step. Loose contacts are connected to the mains. In this connection, the connection is carried out in series, by means of a throttle.

The third step. In parallel to the contacts of the lighting fixture, capacitors are connected. They will reduce the severity of interference in the power grid and compensate for the reactive power that is generated.

Important point! In conventional household switches, in particular this is typical for budget models, contacts can become stuck under the influence of increased starting currents. Therefore, for use in conjunction with fluorescent lighting devices, it is recommended to use only specially designed high-quality switches.

You have got acquainted with the peculiarities of different schemes of connection of fluorescent lamps and now you can independently cope with the installation and replacement of such lighting devices.

Video - Connection diagram for fluorescent lamps