To turn on the light on the street or in public places very often a complete automation of the process is required. The twilight switch with a photocell completely eliminates the human factor when controlling lighting systems.
Content
- What it is
- Types of sensors
- Schematic diagrams of inclusion
- Exploitation
What it is
A twilight photosensitive switch or photo relay is a device that turns off or turns on the light depending on the level of illumination. The device is very convenient to use and has a number of advantages over the classic light switch:
- Full automation of the process. As soon as the level of solar activity decreases to a certain limit, the sensor detects this and turns on the light;
- Power saving The lamp will only light up until the level of sunlight increases again. This allows immediately after dawn to turn off the light in various public places - porches, arches, squares, etc .;
- Ability to set individual on / off parameters. For such purposes, a programmable twilight switch with a built-in timer is used. It allows you to change the settings by setting a specific lamp on time, etc .;
- Any photo switch can be turned off manually. Sometimes unforeseen situations occur during which the device ceases to control the lighting system. In this case, the light relay must be turned off using a standard switch. Not all sensors have a similar function.
Its analogue is a car light sensor, which is built into the windshield. It is necessary to automatically turn on the headlights when entering a tunnel, subway or forest.
Types of sensors
There are four main types of twilight relays:
- The device on the microcontroller, with a timer, photocell and other add-ons (TW1 from ABB - ABB, Luna Star, SOU, LXP-02);
- Remote photocell (Multi 9 ID-RCCB, GFK 3, Plexo, AC-112);
- Built-in photocell (ic-50 Schneider Electric - Schneider Electric, Vega, DeLux YCC);
- With the ability to adjust the threshold (Siemens Steine Night Matic NM 2000, Theben, Energis).
The most common models with a built-in photocell. They are ideal for outdoor use, because their photocell is protected from external factors (water, dust, steam), temperature extremes, and often vandalism. This is a fairly functional device that can be used both at home and to control the illumination of streets, parks, and warehouses.
A switch with a light detection sensor and a timer allows you to control the settings for turning on the light. It determines not only the level of illumination, but also the time interval in which the lamp must be turned on. This is an economical and practical scheme. Depending on the installation location and conditions of use, you can choose models with an hourly timer, weekly, monthly and even annual. They can be installed on a din-river - models with the execution of the type UTFR-1RM.
Nowadays, the production of twilight switches with an adjustable threshold (ic2000p), which are mainly used for indoor use, is being actively carried out. Depending on the adjustment, the photo relay may respond to blackout during a thunderstorm or fog on the street.
If you need to install a control unit and a twilight switch at a short distance from each other, it is recommended to buy a model with an external photocell. A design feature is the ability to mount the power supply and sensor at a distance of up to 150 meters from each other.
Schematic diagrams of inclusion
To install a simple twilight circuit breaker (for example, FB-4M) with your own hands, you need an electrical circuit. Unlike the drawings, where models with a sensor are connected, the diagram below shows a connection option where an ultra-sensitive LED is used as an indicator.
Such an automatic relay takes into account the difference in resistance in the resistors (designation in figure R1 and R2). Moreover, the second resistor - R2 is necessary to control the nominal input voltage VT1. It, using the constant voltage HL1, helps to regulate the threshold for switching on the light.
Also, in addition to connecting a ready-made relay to the network, you can make the light sensors and twilight switches on the comparator for the house or yard. By the way, a simple photo relay can be assembled even from three parts. Conditionally select:
- Photocell;
- Threshold detail (comparator);
- Output relay.
We need to make sure that with a decrease in the level of solar activity, the resistance of the photoresistor (photocell) increases, after which the threshold part should trigger. Next, the photorelay is turned on, turning off (turning on) the light.
A triac can be used as a threshold relay, but a dinistor must be included in the symmetry circuit. Such details are called quadrack. Structurally, they do not differ from triacs with the exception of the upgraded switching circuit.
Kvadrak or Quadrac may have different specifications, you need to choose the optimal parameters. Next, you need to choose the resistance of the resistor, because this is the most important parameter for the twilight switch.
In lighting control systems, the resistance value is determined by the selected photocell, therefore, we recommend starting from the data in the diagram. For normal operation, the simplest photocell (white or yellow) is suitable, in our case, it is a standard photoresistor (FSK-7, FSK-G1).
For the first test of a homemade device with a photosensor, you can use a simple incandescent lamp. But to connect it you need to use a power regulator. Another important working condition is the cooling installation.
Video: device of the simplest twilight switch
Exploitation
Instructions for the use of twilight switches such as Legrand (Langrand):
- Be sure to carefully study the certificate in particular, the paragraphs that indicate the parameters of resistance to moisture and dust - if the level of protection is insufficient, then the device can not be installed outdoors;
- Periodically it is required to wipe the sensor from dust;
- Twice a year it is necessary to arrange control checks of the sensor.
The price of a twilight switch varies from 300 rubles to several thousand. You can buy the device in any city in Russia and the CIS countries (Yekaterinburg, Moscow and others).
- Two-key switch connection scheme for two bulbs
