Maintenance labor

Section "Electrical engineering" 7th grade

Lesson on the topic: "Electric lighting and electric heating devices."

Type of lesson - combined.

Goals:

Give an idea of ​​electric lighting devices and household electrical appliances; study the structure of an incandescent lamp, lamp socket and plug; teach to understand lighting devices; introduce electrical safety rules;

Lesson plan.

1. Report the topic of the lesson.

2. Studying new material.

3. Familiarity with electrical safety rules.

4. Phys. just a minute .

5. Lesson summary.

During the classes

1. Lesson topic message. We continue to get acquainted with electrical work and this year we will get acquainted with electric lighting and electric heating devices, learn how to save electricity, and learn the safety rules for working with electrical appliances.

2. Learning new material.

· Updating knowledge.

What artificial and natural light sources do you know? ( Appendix, slide 2,3,4)

Electric lamps are the most convenient and safest. Electric lighting preserves vision and helps to perform many tasks in the dark.

Everyone should remember that one should not be wasteful when it comes to energy consumption; one must take care of saving it.

Useful light is natural (sunlight), but in the dark you have to resort to

to artificial lighting.

· Introduction to electric lighting devices

In the evening, when it is already dark outside, you turn on household electric lamps at home.

Any lamp consists of a lamp and fittings. The latter includes a socket on which the lamp is mounted; a diffuser lamp, for a more uniform distribution of light, and a reflector, which concentrates the light and directs it to the right place. The lamp body unites and holds together all the named parts.

Cartridge good quality must be made of fire-resistant material: heat-resistant plastic, porcelain or metal. Its durability and safe operation of the lamp depend on this. It is very important that the cartridge is electrically safe. To do this, in modern products the base sleeve is not connected to the contacts until the lamp is screwed in completely, and when this happens, the surface of the base is covered by the cartridge and the possibility of electric shock is practically eliminated.

The reflector is also made of heat-resistant materials. Metal lamps are stronger and more durable than plastic ones. The internal mirror surface of the reflector can be smooth and faceted, that is, cellular, which makes the distribution of light more uniform.

The lampshade softens the light and protects the lamp from possible damage. It must transmit light well to minimize energy loss. There are many types of lampshades: hemisphere-shaped, bowl-shaped, “petal-shaped”, open at the top and bottom, similar to cylinders and expanding flasks.

The lamp body gives the entire lighting fixture strength and makes it easy to handle. Special requirements apply to table lamps. The fastening mechanism should be easy to use and allow placement in any convenient place.

Based on the type of lighting created, the following types of lamps are distinguished:

· household and decorative;

· general and local lighting;

· diffused and directional lighting;

· direct and reflected lighting.

There is also a classification of lamps according to the type of lamps used:

· with incandescent lamps;

· with fluorescent lamps;

· combined.

Lamps must use lamps of the type and power for which they are designed. This must be taken into account when replacing faulty lamps. The total power of a lighting device is not difficult to find out, and it must be taken into account when choosing lamps based on room conditions, the size and shape of the room and the required illumination. The resulting value must not be exceeded, otherwise the electrical wiring may not withstand too much load and burn out.

Depending on the place of fixation, lamps can be ceiling, wall, floor and table. There are also mobile lamps that can be attached anywhere.

The most common are traditional ceiling lamps. Based on their location relative to the ceiling surface, they are divided into suspended, near-surface and built-in. The latter are further divided into panel and point.

Lamp - This is a lighting device designed to illuminate rooms, individual objects and open spaces (streets, etc.).

These are chandeliers, table lamps, floor lamps, sconces, etc. ( Appendix, slide 5). The designs of lamps depend on their purpose. They can be made of metals, plastics, colored glass and other materials.

The light source in household lamps is incandescent lamps ( Appendix, slide 6).

The lamps are screwed into electric lamp sockets, which are included in the lamps. The sockets connect the lamps to the electrical network in the apartment. Lamp sockets can be ceiling, wall or pendant.

In a detachable plastic case ( Appendix, slide 7) using special protrusions and an annular flange, a porcelain core 1 is attached, on which there are spring contacts 3 (central and side) with screw clamps 2 for fastening the wires. The housing 5 has a thread 4 for screwing in the lamp.

For floor lamps, table lamps, and bedside lamps, the wires coming from the lamp socket end in a plug. By inserting the plug into the socket, connect these lamps to electrical network. Recently, mainly non-removable plugs have been used, but collapsible designs can also be found ( Appendix, slide 8).

Electrical switches of various designs are usually placed between the plug and the socket, which are designed to make and break electrical circuit, i.e. turning on and off lighting devices.

On slide 9 in the appendix The design of a pendant switch is shown. In the housing 4 there are two fixed contacts 2 and one moving contact 1. The wires are secured to the fixed contacts with clamping screws 3. ( Appendix, slide 10)

· PRACTICAL WORK(Appendix, slide 11)

· Remember new terms: Household electric lamps, incandescent lamp, lamp socket, plug, switch.

Let's summarize after practical work (Appendix, slide 12,13).

Introduction to the design of a mercury lamp

(Appendix, slide 14).

Why do we get acquainted with the device of a mercury lamp?

What safety regulations must be observed when using mercury lamps?

What other electric lamps do you know?

Introduction to household electric heating appliances.

(Application, PRESENTATION)

3. Let's summarize our lesson

1. What do different lamps have in common and how do they differ from each other?

2. What lamps are used to illuminate the workplace of a seamstress, cook, or draftsman?

3. What are the details of the lamp?

5. Ways to save energy.

6. D/Z

Introduce your family to OHS and lamp care.

Thanks for the lesson girls! Well done!!

Introduction

Electric lighting installations various types carried out in all industrial and domestic premises, in public, residential and other buildings, on streets, squares, roads, driveways. In addition to installations for general use, there are special ones, for example, for irradiating plants in agriculture, for medicinal purposes in medical institutions, regulating and controlling traffic in transport and technological processes in production, etc.

Description of heaters and components on the Steam Systems website.

Special electric lighting devices are called lighting installations. The lighting electrical installation includes light sources, lighting fixtures, ballasts, electrical wiring, electrical installation products and devices, panels, shields and distribution devices. In accordance with the rules for the construction of electrical installations (PUE), a distinction is made between general, local, emergency and security lighting. General

- called lighting of all or part of the room; local

– lighting of workplaces, objects, surfaces; combined

– a combination of general lighting with local lighting, creating increased illumination directly at the workplace.

General lighting can be uniform and localized when lamps are placed so that increased illumination is created at the main workplaces.

The main type of lighting to ensure normal activity in all rooms and open areas where work is carried out in the dark or traffic and people move is working. If it is violated, it is used emergency lighting , providing temporary continuation of work or evacuation of people. Security lighting is integral part

worker and is installed along the borders of the protected area. Working lighting includes repair (portable) and light-enclosing for chimneys and other particularly tall structures.

1. Lamps and spotlights

The luminous flux of most light sources is distributed fairly evenly in space.

For rational lighting of a room or open space, it is usually necessary to distribute the luminous flux of the light source in a very specific way: direct it down or up. For such redistribution of the light flux, lighting devices are used.

Lamps are short-range lighting devices used to illuminate objects located at a short distance.

The lamp consists of a light source and lighting fixtures. The main purpose of lighting fixtures is to redistribute the luminous flux of the light source. It also protects the vision of workers due to excessive brightness of light sources, protects the lamp from mechanical damage, protects the cavities of the location of the light source and cartridge or environmental influences, and serves for fastening the light source, wires, and ballasts.

Optical systems of lighting devices are designed to redistribute the light fluxes of light sources. The elements of optical systems are: reflectors, refractors, diffusers, safety glasses, shielding grilles and rings.

Reflectors– redistribute the luminous flux of the lamp. Depending on the reflection, reflectors can be diffuse, matte or specular.

The main purpose of lighting fixtures is to redistribute the light of the lamp in space. In addition, light fixtures are capable of transforming the properties of lamp light (polarizing it or changing the spectral composition). Equally important are the functions of light fittings such as mounting the lamp and supplying it with power from an energy source, protecting the lamp from mechanical damage and from environmental influences.

Basic classification of lighting devices

As was said, lighting devices are divided according to their purpose into lighting and light-signaling. At the same time, their designs and optical systems do not have any fundamental differences.

If lighting devices are considered from the point of view of light redistribution, then they can be divided into three main types: 1) lamps; 2) floodlight-type devices (searchlights) and 3) projector-type devices (projectors).

A lamp is a light device that redistributes the light of a lamp within significant solid angles.

Lamps create a small concentration of light flux in a certain direction or do not concentrate it at all. Simply put, lamps are designed to illuminate close or relatively close objects.

The design of the luminaire allows the installation of two or more lamps. The lighting fixtures of luminaires with gas-discharge lamps or LEDs may include devices for igniting them, stabilizing their operation, or simply powering them.

Lighting luminaires, as opposed to signal luminaires, are usually abbreviated to "luminaires".

A spotlight is a light device that redistributes the light of a lamp within small solid angles.

The luminous flux of the spotlight is collected into a narrow beam directed strictly in a certain direction. Therefore, the purpose of a spotlight is to illuminate distant or significantly distant objects. The distance to an object illuminated by a spotlight can reach several thousand times the size of the spotlight itself.

Among the spotlights, it is necessary to highlight the spotlights general purpose, search and signal spotlights, beacons, traffic lights and headlights.

General purpose floodlights are used for long-term illumination of work surfaces and open spaces, architectural monuments, building facades and other objects. A common name for this group is floodlights.

Search floodlights are long-range searchlights and are designed for short-term illumination of very distant objects in order to detect them; they can be used as anti-aircraft searchlights, marine searchlights and other objects.

Light beacons (airfield, sea, river, navigation and others) provide signaling about the location of the lighthouse.

Signal spotlights are designed to transmit signals using Morse code or another system. For example, signal spotlights include lighting devices for discotheques. Here is an example of a modern "intelligent" lighting device for discotheques.

Traffic lights are used to transmit light signals that regulate the movement of vehicles and people.

Headlights are external spotlight-type lighting devices installed on vehicles to illuminate the road.

A projector is a light device that concentrates the light flux on a certain small surface (or in a certain small volume). Projectors are the lighting part of light projection optical devices, concentrating the light flux on the frame window in which the picture or slide is located, depicted by the lens on the screen (screen projectors). Technological projectors (concentrators) designed for radiant heating of objects, for example, evaporation of liquids, melting metal, pumping lasers, have also become widespread.

Screen projectors are divided into episcope, diascope and epidiascope. Episcopes are designed to project onto a screen surfaces that send reflected light flux (from drawings, drawings) into the lens. In diascopes, the projected surface (slide, film frame) sends the light flux passing through it to the lens. Epidiascopes can work both as episcopes and as diascopes.

Thus, the main characteristic that determines the division of lighting devices into lamps, spotlights and projectors is the degree and nature of the concentration of the light flux of the lamp in the device beam. In turn, all types of lighting devices can be divided into groups in accordance with the classification below.

Lighting devices are a subclass of lighting products, traditionally also combining light sources, ballasts for gas-discharge lamps and LEDs, as well as lighting electrical installation products.

Additional classification of lighting devices

An additional feature of the classification of lighting devices is their division according to the types of light sources used: incandescent lamps, arc lamps, metal-halogen lamps, low- and high-pressure sodium lamps, xenon lamps, lights, flash lamps, electric arcs, LEDs and others. At the same time, further detailing on this basis is possible, for example, lamps for general-purpose incandescent lamps, incandescent lamps, lamps for miniature incandescent lamps, lighting fixtures for lamp-lamps, and so on. Classification in this direction can be completed by taking into account the standard size of the device by power, the design of the lamp (for example, by the shape of the bulb) and the number of lamps in one lamp.

Similarly, for luminaires with fluorescent lamps we have: luminaires for conventional straight tubular fluorescent lamps, for high intensity fluorescent lamps, for metric fluorescent lamps, for erythematic fluorescent lamps, for reflective fluorescent lamps, for ring fluorescent lamps, for U-shaped fluorescent lamps, for compact fluorescent lamps and so on.

Certain types and groups of lighting devices can be classified into devices of long-term (constant), short-term or flashing action; according to design for work under certain operating conditions (temperature, humidity, concentration of dust, chemically active and explosive substances); on mechanical loads and vibrations; on protection against defeat electric shock; by power supply method (networked, autonomous); if possible, movement during operation; if possible, change the position of the optical system of the lighting device and other signs.

It is interesting to note that it is also possible to classify lighting devices from the point of view of the location of the radiation source in relation to the lighting fixtures. According to this principle, lighting devices can be divided into devices with their own and with an autonomously located radiation source (separated at some distance from the light-distributing elements, for example, lighting devices with LEDs).

From the above it is clear (although the above classification does not affect the shape, material, design features and a number of other distinctive features of lighting devices) how wide the range of these products is. In this regard, it is not surprising that there are several thousand versions of lamps alone for lighting various rooms.

Terms requiring further clarification

General lighting fixtures are called lamps designed for general lighting of rooms and open spaces.

Local lighting fixtures are lamps designed primarily to illuminate work surfaces.

Combined lighting luminaires are devices that create (sequentially or simultaneously) both general and local lighting.

Stationary light fixture- a device fixed to the installation site, the removal of which requires the use of a tool.

Non-stationary lighting device can be removed from the place of operation without the use of tools and moved from one place to another.

Portable light device- a non-stationary device with an individual power source or connected to the mains by a long flexible wire that cannot be disconnected when the light device is moved.

Division of lighting devices according to installation method

According to the installation method, lighting devices are divided as follows.

Hanging lighting fixtures are called devices for fastening to a supporting surface from below using a fastening unit with a height of more than 0.1 m. In this case, a multi-lamp is called a chandelier.

Ceiling light fixture attached to the ceiling directly or using a fastening unit with a height of no more than 0.1 m.

Built-in light fixture called a device for installation in a ceiling, niche or for embedding into equipment.

Attached light fixture is considered to be a lighting device that is permanently mounted on the equipment and is an integral element of it (but not built into it).

Wall light fixture Designed for installation on a vertical supporting surface.

To subgroup support lighting devices include table, floor, crown and console lamps. In this case, support lamps are understood as lamps designed for installation on the upper side of a horizontal surface or fastening to it using a stand or support. If by table lamps we mean lamps for installation on a table or other furniture, by floor lamps - for installation on the floor, then a crown lamp is a support lamp for illuminating open spaces, and a cantilever lamp is a support lamp, the light center of which is shifted relative to the vertical passing through the point of attachment of the support .

Hand-held light device called a portable device that is connected by a flexible wire to the power supply and is located in the hand during operation. At the same time, it is a portable light device that is powered by an individual current source and is located in the hand during operation.

Head light during work it is located on the head.

End light fixture Designed for installation in the rear of vehicles.

It should be noted that the terms “sconce” (synonym for wall lamp), “floor lamp” (floor lamp), and “plafond” (ceiling lamp), previously used in a number of cases, are not currently used.

The term “decorative lamp” found in lighting literature refers to a lamp that is primarily a decorative element of the interior or exterior and plays a limited role in creating necessary conditions lighting, and a “night light” is usually called a lamp that provides the ability to orientate in a room at night.

Lighting fixtures is a lamp without a light source.

It is necessary for attaching the lamp, redistributing and converting the light flux, and protecting the eyes from blinding light. The fittings included with the light source constitute a lamp.

The range of lighting fixtures is classified according to a number of criteria: by type of lamp- for fittings for incandescent lamps and fluorescent lamps; by appointment- for general, local, decorative, combined, orientation (night lights), exposure and special lighting; by number of lamps- one-, two-, three- and multi-lamp; by design- for symmetrical and asymmetrical lamps with a constant and variable light center.

Symmetrical lamps by the nature of light distribution are divided into five classes - P - direct light, N - predominantly direct, P - diffused, B - predominantly reflected, O - reflected light; according to the type of light intensity curves(illuminance distribution curves): concentrated (K), deep (D), cosine (D), semi-wide (L), wide (W), uniform (M), sine (S) lamps; by degree of environmental protection- unprotected, dust-proof, dust-proof, splash-proof, jet-proof, waterproof, sealed; according to the class of protection against electric shock- O, 01, I, II, III classes; on fire safety- for lamps installed on combustible and non-combustible material; according to the installation method ovki - stationary and non-stationary; stationary at the mounting location- for ceiling, wall, built-in, suspended, attached, crown, console, end; non-stationary - table-top, floor-mounted, hand-held, head-mounted; by type: for ceiling lamps (attached directly to the ceiling); pendant lamps (light sources are located at some distance from the ceiling); wall lamps - sconces; floor lamps - floor lamps; desk lamp; night lights (installed for orientation at night on bedside tables, in children's rooms, in places where the first aid kit is located, etc.); hand lamps; based on diffuser materials- for glass, plastic, textile, wood, wire, metal, wicker; by design features- with specular, matte and diffuse reflection of light.

The quality of light sources and lighting fixtures is regulated by relevant technical regulations. It is ensured by the correct packaging, therefore, first of all, the integrity and standardization of the packaging, the integrity of the products, and completeness are checked. Products must have a uniform protective and decorative coating, be correctly assembled, functional, stable, without mechanical damage, traces of corrosion, or damage to electrical insulation. Non-compliance of the dimensions of the base with the requirements of the standards, the presence of opaque defects on glass flasks, corrosion on the base, and exposed conductive conductors are unacceptable.