High and low pressure discharge lamps: prices - Asutpp

Electrical devices consisting of a transparent container in which the gas is powered by voltage, due to which the process of luminescence occurs, are called discharge lamps. We offer you to consider how high-pressure discharge lamps and incandescent lamps differ, how this device works and where to buy them.

Principle of operation of a discharge lamp

A gas discharge lamp is a light source that generates light, creating an electric discharge through ionized gas. Typically, these lamps use gases such as:

• argon,
• neon,
• krypton,
• xenon, as well as mixtures of these gases.

Many lamps are filled with additional gases such as sodium and mercury, while others use metal halide additives.

When power is applied to the lamp, an electric field is generated in the tube. This field forms inclusions of free electrons in the ionized gas, i.e. provides collision of electrons with gas and metal atoms. Some electrons orbiting these atoms provide collisions to a higher energy state. In such cases, photon energy is released. This light can be anything from infrared visible to ultraviolet radiation. Some lamps have a luminescent coating on the inside of the bulb to convert ultraviolet radiation into visible light.

Some tubular lamps contain a special beta radiation source to allow ionization of the gas inside. In these tubes, the glow discharge provided by the cathode is minimized in favor of the so-called positive energy column. The most striking example of such a technology is energy-saving neon lamps, gas-discharge pulsed IFK and fluorescent.

Gas discharge lamps and types of cathodes

Many have heard the term CCFL cold-cathode fluorescent lamps and hot-cathode lighting devices. But what is the difference, what is their labeling and which ones to choose?

Hot cathode

An electrode with thermionic emission generates electrons in hot cathodes. That is why they are also called thermionic cathodes. The cathode is usually an electric filament of tungsten or tantalum. But now they are still covered with a layer of emission material, which can produce more less heat and light, thereby increasing the efficiency and luminous flux of a discharge lamp. In some cases, when buzzing AC is a problem, the heater is electrically isolated from the cathode. This method is widely used by gas-discharge metal halide lamps (hpi-t plus, deluxe, hid-8) and low-pressure lamps.

Light sources with hot cathodes produce significantly more electrons than cold cathodes with the same surface area. They are used by indicator devices, microscopes, and even such lamps are used to modernize electronic guns.

Cold cathode

With a cold cathode, thermionic emission is not performed. In this case, high-voltage lamps operate on electrodes that generate a strong electric field (say, make), which ionizes the gas. The surface inside the tube is capable of producing secondary electrons, while minimizing their “drop”. Some pipes contain special grounding, which improves the emission of electrons.

Another method of operation of cold light devices is based on the generation of free electrons without thermionic emission, due to field electron emission. Field emission occurs in electric fields, which create a very high voltage. This method is used in some x-ray tubes, microscopes, working at the expense of electric fields, and also it is used by gas discharge sodium lamps (lhp, dnat 400 5, dnat 70, dnat 250-5, dnat-70, hb4).

The term “cold cathode” does not mean that it remains at ambient temperature all the time. The working temperature of the cathode may increase in some cases. For example, when using alternating current, due to which the electrodes changed places - the steel cathode became the anode. Some electrons can also cause localization of heat. For example, fluorescent lamps: after starting, the tungsten wire is cold, the lamp works with a cold cathode and the phenomenon described above is used to heat the filament. When it has reached the desired light level, the lamp operates normally, as with a hot cathode. A similar phenomenon can be demonstrated by some drl xenon discharge lamps (d2s, h4 category d).

The cold cathode of the device requires high voltage, but a high-voltage power supply is not required. This is often called a CCL inverter. The inverter works by creating a high voltage to organize the initial space charge and the first electric arc of the current in the tube. When this happens, the internal resistance of the tube decreases and increases the current. The converter responds to such changes, and if the temperature exceeds the norm, it turns off. Most often, such systems are installed for street lighting.

Cold light bulbs are often found in electronic devices. CCFLs (cold cathode fluorescent tubes) are used as diode bulbs for computers, modems, multimeters, in-14, in 18 and HB 3 discharge indicators, and more. In addition, they are widely used as LCD backlight. Another example of widespread use is Nixie pipes.

Types of discharge lamps

Before you buy any device, you must definitely study all its characteristics.

High pressure discharge lamps

These lamps contain compressed gas inside the pipe at a higher pressure than atmospheric pressure. For example, high-voltage discharge lamps are metal halide (osram hqi-t 2000w / n / sn), sodium (lu250 / t / 40, philips philips son-t 1000w \ 220 e-40, msd 575, msd250 and gbm 150) and mercury lamps dr or drv (drt-240, ml 250 / e40,).

Low pressure lamps

These lamps contain gas inside the pipe at a lower pressure than atmospheric. Classic way fluorescent lamps belong to this category, now well-known neon lamps, as well as low-pressure sodium lamps, which are used for street lighting. All of them have very good efficiency, but the most effective among all discharge lamps are son sodium lamps. The problem with this type of lamp (with r7s socket) is that it produces only almost monochromatic yellow light (with the exception of throttle fluorescent lamps).

High Intensity Discharge Lamps

In this category, there are lamps that emit light using an electric arc between the electrodes (e-27). The electrodes are usually represented by tungsten electrodes, which are located inside a translucent or transparent material. There are many different examples of HID (High Intensity) lamps sold in our country, such as halogen (ipf h4 x-41, mn-kh7s-150vt, hq-t), xenon arc, and ultra-high performance lamps (UHP).

Cons in the work of discharge lamps

Any devices have their drawbacks, and gas discharge lamps were no exception:

• if the mains voltage is less than 220 V (say 100), then metal halide lamps (hmi-1200) will not work;
• prohibition of use in educational institutions;
• halogen lamps become too hot during operation. They pose a certain fire hazard, and in addition require very scrupulous care - 1 drop of fat on the surface can cause it to explode;
• neon lamps emit light (especially if the UV series, model n4), which is harmful to the eyes with prolonged contact.

Application area

High-intensity automotive discharge lamps, both neon, are widely used, and diode lighting is sometimes used for cars (their price is slightly lower). The discharge of a car headlight is filled with a mixture of xenon gas and metal halide salts (as for example, Toyota Corolla uses d2r for toyota estima 2000, or BMW 5 for Opel astra j)). Light is created by striking an arc between two electrodes. The lamp has a built-in igniter.

For lighting industrial premises (gu-23a, ld30, tn-0, 3, gu26a), street areas (olympiad 250, Sylviana made in Ukraine), billboards, building facades, as well as high-pressure daylight discharge lamps in apartments and houses (GOST 500-9006-083) and in ballasts.

The installation and wiring diagram are exactly the same as when installing simple incandescent lamps.