Daylight lamp: device device with and without a starter, types of bulbs, connection diagram

Lighting is an important part of the work and life of a modern person. From workshops and offices to living quarters, lighting devices are now everywhere. Many of them use fluorescent gas-discharge light sources, better known as fluorescent lamps.

Description of fluorescent lamps

Relatively recently, fluorescent lamps were not in such wide demand, since the spectrum of shades they produced was extremely small: white-pink and white-green. But with the development of lighting equipment, fluorescent light bulbs were modernized and improved. Moreover, they made it possible to create lamps of almost any design, and the lamp itself could be given any complex shape. And the greatly expanded spectrum of luminescence and low power consumption made it possible not only to catch up, but also to surpass the popularity of conventional incandescent lamps.

With regard to the device, such lighting devices are a flask, the inner surface of which is covered with a thin layer of phosphor and filled with mercury vapor. When an electric current occurs, mercury begins to emit ultraviolet light, which converts the phosphor into visible light. The more lumens, the more light output the lamp has. The degree of illumination is usually measured in lux.

In addition, the flask is filled with an inert gas, which makes it possible to obtain a glow of various shades. So, if neon is used, then the light will be red, argon products give out a blue tint, and bulbs filled with helium can give out from light yellow to pale pink.

Principle of operation

Fluorescent lamps are based on the same principle as an ordinary incandescent light bulb. This is an improved form of the latter. After all, the fluorescent lamp circuit is more complex than its filament tax. Although tungsten filaments are also present here, which, when exposed to an electric current, heat up strongly. Perhaps this is the most basic similarity between both options.

Despite the outwardly apparent complexity of the device of fluorescent lamps, they work according to a simple principle. An arc discharge occurs between the electrodes located at opposite ends of the device when voltage is applied.

The flask is filled with any inert gas and a small amount of mercury, which, when exposed to current, begin to emit ultraviolet light.

Since the human eye cannot see UV, it has to be converted into visible light. This is perfectly handled by the so-called phosphor, which is applied to the inner surface of the glass bulb. It is usually based on calcium or zinc derivatives. Although the use of other elements is quite acceptable. After all, the shade that the light of the device gives depends on the composition of the phosphor.

The resulting arc discharge is constant due to the fact that electrons are knocked out from the cathode surface due to the high temperature. The cathodes are heated by passing a current through them, or by bombarding ions in a high-voltage glow discharge, where ballast is used to limit the current.

Ballast, or ballast machine, helps to solve a number of problems that arise when using LDS. After all, fluorescent lamps cannot be directly connected to the network, since they have a rather high resistance, which, in turn, requires a high voltage pulse to obtain a discharge for ignition. In addition, it is imperative to include a resistance in the circuit, which will not allow a short circuit to occur, as a result of which the lamp will burn out. This happens due to the negative differential resistance that occurs during the appearance of a discharge in the lamp.

Types and forms

Despite the general external similarity, there are significant differences between different fluorescent lamps. So, there are low and high pressure options. As the names suggest, some are filled with gases under low pressure, while others, on the contrary, under high pressure. If it is necessary to illuminate a living room, office or workshop, then it is preferable to use low pressure LDS. As for products with high pressure, it is customary to operate them in devices that require high power, for example, when setting up street lighting.

This is not the only difference between such products. Another important characteristic is the emission spectrum. The light emitted from the lamp appears to be white, but in reality it can distort the colors of the surrounding objects. This is due to the fact that the phosphor used emits some colors more and others less. The eye is unable to see such a difference, but it perfectly perceives color distortion in the environment. However, such lamps have good luminous efficacy, which is also valuable in a number of cases.

If we recall biology, then the eye has three types of color receptors, the rest is refined by the brain. Thus, you can "trick" him and make LDS that allow you to see the entire spectrum. To do this, it is enough to use a three-band or five-band phosphor. True, such options will cost much more.

As you can see, the choice depends directly on the needs and the place that needs to be illuminated. Therefore, there is a special marking that allows you to determine what luminosity the product gives:

• D - this is how an ordinary standard lamp is indicated.
• LDC - lamps marked with such letters have an improved chromaticity index.
• LB - marking indicates that the light bulb emits white light.
• LHB - it is understood that the lamp shines with white, but already cold light.
• LTB - such fluorescent lamps also emit white, but already warm light.

As far as form is concerned, there is unlimited variety. In most cases, simple linear fluorescent lamps are known. But more and more often you can see compact curved, U-shaped and other shapes. This allows you to make the lamp itself more compact, beautiful and convenient. And the options for the standard marking E27, E14 and E40 are designed to be used instead of incandescent lamps in various lighting fixtures.

Ballasts

There are two types of ballasts. Today, daylighting devices with electromagnetic (EMPRA) and electronic (ECGRA) ballasts are most in demand.

Electromagnetic ballast is a choke with a given inductive resistance, which is connected in series to a lamp (or several lamps) of known power. The starter in the form of a neon lamp with bimetallic electrodes, as well as a capacitor, are connected to the filaments in series. Between themselves, the neon lamp and the capacitor are connected in parallel.

The choke allows, due to self-induction, to obtain a starting pulse of up to 1 kV, while at the same time limiting the current passing through the lamp due to the inductive resistance.

Despite the simplicity, reliability and durability, this scheme for connecting a fluorescent lamp with a starter still has several disadvantages:

• Long (up to 3 sec.) Lamp start-up.
• The choke consumes a tremendous amount of energy.
• With an old or poor quality choke, a low-frequency hum may occur.
• Flickering, which negatively affects vision, as well as when the rotation coincides with the frequency of the network, moving parts may seem stationary. As a result, bulbs with such ballast are prohibited to illuminate mechanisms with rotating parts without additional illumination.
• Large weight and considerable dimensions.
• Do not work at low temperatures.

Electronic ballast, designated electronic ballast, is a more modern and preferable analogue. Him there are practically no drawbacks, but there are many advantages, which distinguishes it from electromagnetic.

• Due to the fact that the lamps are powered by high-frequency voltage from 25 to 133 kHz, and not by standard mains (50-60 Hz), the possibility of flashing is completely excluded. This has a positive effect not only on vision, but also on work in general. Especially with moving parts of mechanisms and machines.
• Electricity consumption is 20-25% lower than when using an electromagnetic device.
• Significantly lower costs not only for disposal, but also for manufacturing, since less copper and iron are used.
• A centralized lighting system is possible, automatically adjustable, which saves energy up to 85%.
• Some versions of electronic ballasts allow you to dim the lamps.

Advantages and disadvantages

When choosing lighting equipment, a person should be aware of the pros and cons of fluorescent lamps. So, the main advantages are:

• excellent luminous efficacy and high efficiency rates;
• long time of operation;
• lighting perceived by a person as almost natural;
• excellent color rendering;
• low sensitivity to power surges;
• excellent pricing policy.

Of course, they also have their drawbacks, which are not an obstacle to their high popularity among the population. The main disadvantage can be considered the presence of mercury in such products, which makes it in some kind of dangerous, but with proper operation and timely disposal, this indicator tends to minimum.

Some models of such illuminators can produce pulsations that are harmful to the organs of vision. However, choosing a lamp and taking into account a number of nuances, this disadvantage can be avoided.

A decrease in the level of luminous flux during operation is also inevitable. But despite this, subject to the simplest conditions of use described in the instructions for the product, the time of high-quality work is measured in tens of thousands of hours., which is much more than the expected operation of incandescent lamps.

Disposal of defective products

Since fluorescent lamps contain mercury, which is a toxic substance of the 1st hazard class, such products must be subject to mandatory disposal and recycling. Constant exposure to mercury vapor on a person does not have a very good effect on his health. Therefore, out of order and used products are supposed to be handed over to special collection points, which accept them free of charge. Such points can be located in the housing department, DEZ, REU and even in stores.

After that, the used lamps go through the stage of disposal and thermal demercurization, due to which mercury in a dose of 1 to 70 mg per product is collected and used in further production.