How to connect a light switch? The scheme

The light switch can be a simple electrical device, as well as a complex switching device. They are designed for different control schemes for lighting devices. When installing the wiring, it is important to connect the light switch correctly. Connection scheme in the classical version is the application of the simplest device with a single key.

Its contacts are opened when the lighting is switched off and closed when it is turned on. The phase passes through the switch, and the zero is connected to the lamp. Confusing the order of connection can not be, otherwise the lamp will constantly be voltage.

Connection of a single-key switch

The devices are designed for indoor and outdoor installation. The connection scheme of the light switch with one key provides switching of the luminaire or group.

If there are more lamps, the main connections are also made through the junction box.

Features of using several keys

The circuit of the double light switch allows you to control the same number of luminaires. Here, the lamps are switched separately through one switching device, depending on which of the two keys is pressed. The method is common for incorporating a chandelier. Less commonly used are three-key models.

The difficulty of replacing a device with a large number of switches is the need to lay additional phase wires to the luminaires and the switch. Connection diagrams are indicated on the rear side (three outputs for a two-key device).

In essence, the switch represents two elementary devices, combined in one housing. When one of the keys is turned on, the phase is fed to the corresponding luminaire. The voltage is applied to the input terminal (clamp). Two contact groups are connected to it, each of which has its own key. Connect the lamps to the output terminals.

The three-key light switch works in a similar way. The principle of operation consists in switching wires connected to individual lamps or their groups.

Connecting the lighting system in an apartment or house

In houses and apartments power and lighting circuits are divided among themselves and protected by separate automatic devices. If the first one fails, the light continues to burn, which makes it easier to find and fix the problem. If the second circuit is disconnected, it can be repaired by connecting the transfer to any of the outlets.

From short circuits and exceeding the long-lasting current, the lighting system is protected by an automatic switch with a rating determined by the total capacity of all lamps.

Switch arrangement

The following types of household switches are produced:

• Internal;
• External;
• With protection from moisture;
• Modules.

When mounting in a wall, models for concealed wiring are used. First, a notch is drilled in the concrete, into which a podzheetnik is inserted and wires are laid. As a result, the device is inserted into the wall and is located at the level of its surface.

The switch and the sub-socket are sold separately. They must be suitable for each other, as well as for mounting in a wall or in a thin partition.

External switches are used for open wiring, which passes through pipes or cable channels. Under them, a wooden or plastic platform is installed, attached to the wall with screws or dowels.

Modules are mounted on special cable channels and used in office premises or in enterprises.

Devices with moisture protection are installed in bathrooms, baths, in other damp areas or in places where they can get water droplets.

How to connect a light switch:

As the elements to which wiring is connected, there are terminal blocks - mechanisms with self-clamping contacts. For connection, the end of the core is stripped and inserted into the hole where it is clamped by spring-loaded contacts.

Instead of the terminals in the switch, screw terminals can be installed. They insert the end of the stripped wire and tighten by tightening the bolt.

The switching mechanism contains a movable contact, occupying 2 fixed positions: "on" and "off". Depending on which of them is the key, the electrical circuit will be closed or open.

Switch selection

The device is bought in a specialized store, where you can choose the most suitable in appearance and parameters. The switch must match the power of the fixtures. Its price depends on this. For example, contacts made of cermets containing silver are designed for an electric current of 4 A.

With a variety of designs, switches should be selected for a specific purpose. They can be key, push-button, wall, ceiling, swivel, flip-flop, pass-through, etc. Particular attention is drawn to the fact that the light switch is designed for external or internal wiring. The scheme of its connection is also important, because it performs a certain function.

It is important to check the build quality of the device and how the keys are clearly switched.

Sensor light switches

The outer panel is a glass decorative plate with markings. Under it is located a sensitive element that reacts to a light touch or approach of the fingers. In this case, a signal is generated, which is converted by a semiconductor circuit into an electrical circuit, perceived by the switching part. Depending on the place or duration of contact, the circuit closes or opens, and the luminosity of the luminaires is gradually adjusted.

For greater convenience, remote control panels associated with several similar switches are used.

The number of functions for different models differs and depends on the price. The devices are equipped with motion sensors, temperature, lighting, etc. They can be connected to an electric fireplace, air conditioning, lights and a security lighting system around the perimeter of the house.

Principle of operation of the sensor switch

There are many electronic circuits. Below is a simple scheme of the sensor light switch , which you can assemble yourself.

When a person touches the sensitive element E1, a small potential from the body is transmitted to the two-stage amplifier through the capacitor C1. To the output of transistor VT2 is connected relay K1, triggered or disconnected at the next touch. Its power contacts are connected to the lamp supply circuit (not shown in the diagram). The capacitor C2 is a filter that smooths the voltage pulsations, and the diode VD1 protects the transistor VT2 from voltage surges.

This circuit of the light switch contains a relay, the operating current of which is 15-20 mA. To configure it, a variable resistor R1 is connected and the resistance is changed until the contacts begin to switch reliably. Then a suitable nominal value is selected.

The sensor plate is made of foil-coated textolite or a copper plate coated with varnish against corrosion. The lead wire is shielded.

The battery can be a 9 V battery or a charger from the phone.

Feedthrough switches

Devices are designed for easy control of lighting in long corridors, on staircases, walk-through rooms or on descents to the basement. Several switches located in different places, it is convenient to use for one lamp. The lighting control becomes more comfortable and economical.

Circuit breakers for light switches

Devices contain 3 contacts on each of them (1 common input and 2 changeover output). From two switches located at a distance from each other, you can collect the simplest and most common lamp control scheme.

When you press a button, one of the change-over contacts opens one circuit, closing the other (or vice versa). In the first switch, the input terminal 1 is connected to the phase, and in the second switch to the luminaire. Output contacts 2 and 3 of one device are connected to the corresponding other.

If properly connected, the lamp should light up and go out one after the other, when one of the switches switches. When a single chain is broken, both lines are prepared for subsequent switching. Here, each key does not have a fixed "on" and "off" position.

Below is shown how the light switches on with two switches. The circuit is assembled mainly through a junction box. It produces all the main connections. In order not to be mistaken when making connections, the wires should be labeled.

Two-key pass-through switches

The scheme of connection of light by two switches for controlling one lamp or a group is the simplest. If you take more complex - two-key, you can independently control two lights. At first glance, the circuit seems complicated, but, in fact, it represents two connections for a pair of single-key pass-through switches. In this case, the number of inputs and outputs doubles.

After the circuit is assembled, it is advisable to check it using a multimeter. To do this, its probes should ring the input and output contacts of the switch. Switching the keys, you should monitor the tester's readings. If the circuit closes and opens as expected, you can connect the circuit to the network.

Conclusion

For specific lighting control conditions, a certain light switch is used. The scheme of its connection is directly related to the design features. The most common are simple models that ensure the opening or closing of the electrical circuit. The circuit is complicated by using two and three keys, with which you can switch the same number of fixtures or control the brightness of the chandelier. In addition to them, pass-through switches appeared, which allow to regulate the lighting from different places. Then the systems of remote and sensory control began to be manufactured, due to which the functionality of the lighting system increased significantly . Despite the high prices, such switches are increasingly used, thanks to the creation of comfortable conditions and energy savings.