The single-key walk-through switch is a special kind of household switching devices, the need for which arises in special cases. Their installation is advisable in the passage rooms, in which it is necessary to turn on the lighting from the side of the entrance, and turn it off at the exit. For this, the circuit breaker kit includes two electrically interconnected devices installed in appropriate places.
Application examples
The capabilities of such switches allow you to avoid many inconveniences that have to be faced in everyday life. An application example is the case when the user needs to cross a long corridor, and it is advisable to do this not in the dark, but in full light. When exiting, a second keyboard device is used, through which the light can be turned off. Moreover, the direction of movement in such an object does not matter.
The system is built so that after passing through the corridor, the switch is ready for a new actuation, but already at the entrance from the other side.
Other places where a paired switching device is often installed are the entrance to the bedroom and the area in the area where the bed is located. In this situation, you can enter the illuminated room, and then turn off the light, preparing for bed.
Features and principle of operation
To understand the difference between a typical pass-through switch and a conventional switching device, you will need to understand how to connect them. A simple product is included in the gap of the phase wire laid to the chandelier, and has only two contacts. The single-key walk-through switch has three working terminals that allow you to commute two parallel lines. By means of a third, additional contact, one circuit is opened and another is closed.
Such switches should be installed only in pairs, which ensures the sequence of switching the lighting line from two points remote at significant distances.
The similarity with conventional devices is limited in that they are also included in the phase wire break.
The principle of operation of the passage switch is based on switching the same line by alternately supplying voltage to the bulb from two sides at once. This possibility is realized due to a special switching circuit, according to which two wires are connected to the lighting device (each of them is supplied with a voltage of 220 volts alternately).
When wiring such circuits, the cores are distinguished by the marking of insulation, one of which is gray, and the second is white.
In order for one of the two pass-through single-key switches to work, the key of the second must be in the on (upper) position. Only in this case, the phase voltage supply circuit from the side of the second device will be closed, and the principle of operation of the light switches will be performed.
Types of passage switches
By the number of switching contacts, the following types of passage switches are distinguished:
- single-key;
- two-key;
- three keys.
The number of keys can mean a lot for the functionality of each of the listed devices, since they allow you to switch illuminators from three or more points in the room.
If it is necessary to control from 3 or more places, the most optimal option is a two-key device with cross-control.
When comparing multi-key switches with their single-key counterparts, it is important to understand how one of them can differ from the other. Basically, the difference concerns the functionality of indoor devices. If in the second case only one group is switched (the illuminator turns on and off), then in a circuit with a two-key switch there will be two such groups. In accordance with the scheme of their connection, you can turn on the first of two illuminators, while simultaneously turning off the second or vice versa.
By design, such switches can have an open (external) design or can be installed in niches pre-prepared in the wall. According to the control method, the switch can be touch-sensitive or with a remote control, that is, it can be triggered by touch or at a distance (remotely). The choice of a specific type of device is determined by the user's preferences, as well as his financial capabilities.
Three-Point Switching
In order to be able to turn on the light from 3 points, it is necessary to supplement the previously described scheme for a paired single-key device with another - a cross-key element. This switch can be located at any point in the room, located between two already mounted products.
It consists of two switches already considered earlier, located in one solid case. In it, a common button is installed on a conventional flip-flop mechanism, consisting of two parts, which allows you to commute the lines leaving from it synchronously. To get a triple two-gang switch, you will need to modify the usual cross-device by installing jumpers on it.
The multi-point connection scheme is organized in such a way that the "ground" wire is wound in parallel into two lighting groups, and a phase (in red insulation) is supplied to each of the input terminals of the first switch. Regardless of the position of the keys, the voltage will be supplied only through the even input terminals (through white and gray wires), and only then through the previously installed jumper does it get to the input of the second pass-through switch.
The direction of the phase potential supply to the lighting devices depends on the position of the keys. If one of the groups of illuminators is on, it is enough to turn off any of the devices to turn off the power. The same process occurs when it is turned on, only in this case, a change in the position of any key entails the restoration of the power circuit.
Choice of execution option
When choosing the appropriate type of single-button through-switch, the following points are taken into account:
- First of all, you will need to determine the brand of the purchased device, which is selected based on personal preferences;
- the number of switching keys is selected, which depends on the required number of points from which the illuminators should be controlled;
- determines the installation method of the purchased device (in open or closed version).
The passage key switch, in accordance with its functional purpose, allows you to control illuminators from two or three remote points, facilitating the handling of them.
