The light switch can be a simple electrical device, as well as a complex switching device. They are designed for different control schemes of lighting devices. When wiring, it is important to connect the light switch correctly. The connection scheme in the classic version is the use of a simple device with one key.
Its contacts open when the lights are turned off and close when turned on. In this case, the phase passes through the switch, and zero is connected to the lamp. It is impossible to confuse the connection order, otherwise the lamp will constantly have voltage.
Single Key Switch Connection
Devices are designed for indoor and outdoor installation. The wiring diagram for a light switch with a single key provides switching of a lamp or group.
If there are more lamps, the main connections are also made through the junction box.
Features of using several keys
The double light switch circuit allows you to control the same number of fixtures. Here, the lamps are switched separately through a single switching device, depending on which of the two keys is pressed. The method is common to include a chandelier. Three-key models are less commonly used.
The difficulty of replacing a device with a large number of switching is the need to lay additional phase wires to the lamps and the switch. The wiring diagrams are indicated on its rear side (three pins for a two-key device).
In essence, the circuit breaker represents two simplest devices combined in one housing. When one of the keys is turned on, the phase is supplied to the corresponding lamp. Voltage is applied to the input terminal (terminal). Two contact groups are connected to it, each of which has its own key. Lamps are connected to the output terminals .
The three-key light switch works similarly . The principle of operation is the switching of wires connected to individual lamps or their groups.
Connecting a lighting system in an apartment or house
In houses and apartments, power and lighting circuits are separated and protected by separate automatic machines. When the first of them fails, the light still continues to burn, which facilitates the troubleshooting. If the second circuit disconnects, it can be repaired by connecting the carrier to any of the outlets.
From short circuits and exceeding the long-term permissible current, the lighting system is protected by a circuit breaker with a rating determined by the total power of all lamps.
Switch device
The following types of household switches are produced:
- domestic;
- outdoor;
- with protection against moisture;
- modules.
When mounting in the wall, models for hidden wiring are used. First, a recess is drilled in the concrete, into which the socket 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 socket are sold separately. They should be suitable for each other, as well as for installation conditions in a wall or in a thin partition.
Outdoor switches are used for open wiring that runs through pipes or cable channels. Under them, a wooden or plastic platform is installed, attached to the wall with screws or dowels.
The modules are mounted on special cable channels and are used in office premises or at enterprises.
Devices with moisture protection are installed in bathrooms, baths, in other damp rooms or in places where drops of water can get on them.
How to connect the light switch: circuit
The elements to which the wiring is connected are terminal blocks - mechanisms with self-clamping contacts. To connect, the end of the core is stripped and inserted into the hole where it is clamped by spring-loaded contacts.
Instead of terminals in the switch, screw terminals can be installed. They insert the end of the stripped core and tighten by tightening the bolt.
The switching mechanism contains a movable contact, occupying 2 fixed positions: “on” and “off”. Depending on which key the key is in, the electric circuit will be closed or open.
Circuit breaker 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 it. For example, contacts made of cermet containing silver are designed for an electric current of 4 A.
With a variety of designs, switches should be chosen for a specific purpose. They can be keyboard, button, wall, ceiling, rotary, flip, walk-through, etc. Particular attention is paid to the fact that the light switch is designed for external or internal wiring. The wiring diagram is also important because it performs a specific function.
It is important to check the build quality of the device and how the keys switch clearly.
Touch light switches
The outer panel is a glass decorative plate with a marking. Below it is a sensitive element that responds to a light touch or proximity of the fingers. When this occurs, a signal is converted by the semiconductor circuit into an electrical one, perceived by the switching part. Depending on the place or duration of the touch, an electrical circuit is closed or opened, as well as a smooth adjustment of the brightness of the fixtures.
For greater convenience, remote control panels associated with several switches of the same type are used.
The number of functions for different models differs and depends on the price. The devices are equipped with motion, temperature, light sensors, etc. An electric fireplace, air conditioning, lights and a security lighting system around the perimeter of the house can be connected to them.
The principle of operation of the touch switch
There are many electronic circuits. Below is a simple diagram of a touch light switch that 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. Relay K1 is connected to the output of transistor VT2, which trips or disconnects when it is touched again. Its power contacts are connected to the lamp power circuit (not shown in the diagram). Capacitor C2 is a filter that smooths voltage ripples, and diode VD1 protects the transistor VT2 from voltage surges.
This light switch circuit contains a relay with a trip current of 15-20 mA. To configure it, a variable resistor R1 is connected and the resistance changes until the contacts begin to switch reliably. Then a suitable face value is selected.
The sensor plate is made of foil 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 phone charger.
Feed-through switches
The devices are designed for convenient control of lighting in long corridors, on stairs, walk-through rooms or on descents into the basement. Several switches located in different places, it is convenient to use for one lamp. Lighting control at the same time becomes more comfortable and economical.
Schemes of passage light switches
Devices contain 3 contacts on each of them (1 common input and 2 cross over output). From two switches located at a distance from each other, you can assemble the simplest and most common lamp control circuit.
When a key is pressed, one of the changeover contacts opens one circuit, closing the other (or vice versa). In the first switch, the input 1 terminal is connected to the phase, and in the second to the luminaire. Output contacts 2 and 3 of one device are connected to the corresponding another.
When connected correctly, the lamp should turn on and off sequentially when one of the switches switches. When one circuit breaks, both lines are prepared for subsequent switching on. Here, each key does not have a fixed “on” and “off” position.
Below is shown how the light turns on with two switches. The circuit is assembled mainly through a junction box. It produces all the basic compounds. In order not to make a mistake when connecting, the wires should be marked.
Two-button walk-through switches
The circuit for connecting light with two switches to control a single lamp or group is the simplest. If you take the more complex - two-key, you can independently control two lamps. At first glance, the circuit seems complicated, but, in fact, it consists of 2 connections for a pair of single-key walk-through switches. The number of inputs and outputs doubles.
After the circuit is assembled, it is advisable to check it with a multimeter. To do this, its probes should ring the input and output contacts of the switch. Switching the keys, you should follow the tester. If the circuit closes and opens as expected, you can connect the circuit to the network.
Conclusion
A specific light switch is used for specific lighting control conditions. The scheme of its connection is directly related to design features. The most common are simple models that open or close an electrical circuit. The scheme is complicated by the use of two and three keys, with which you can switch the same number of lights or control the brightness of the chandelier. In addition to them, walk-through switches appeared, allowing you to adjust the lighting from different places. Then, remote and touch control systems began to be produced, due to which the functionality of the lighting system significantly increased . Despite the high prices, such switches are finding wider application due to the creation of comfortable conditions and energy savings.