With the onset of the evening along the city streets themselves lighted the lights, the automation of this process is no surprise. Today, photosensors, managing street lighting, are available not only to utilities, but also to ordinary owners of country houses. Make your home more comfortable and smart you can without the special financial costs and wiring skills, one only has to take into account several important nuances: to know the connection diagram of the photocell and the rules of operation with him.

How the light sensor works

The task of the photocell is to turn on the lighting device when it becomes twilight in the courtyard and turn it off with the onset of dawn. At the heart of the device is a photosensitive element (photodiode, gas-discharge detector, phototyristor, photoresistor), which changes its characteristics in the light. For example, in a photoconductor resistor decreases, the current easily passes through this element and closes the contact that turns off the lighting.

Additional elements of the device help to avoid erroneous on / off, adjust the sensitivity of the sensor, amplify the signal from the sensor, etc.

Why you need a photo relay

The street lighting system can work without photosensors. But the sensor day-night gives it additional advantages:

• Convenience. A standard lighting system involves the installation of a switch near the front door on the street, or in the house itself. It is convenient for someone who decided to leave the house late at night. But when returning home in the dark period of the day, you have to go to the switch with a flashlight, or even open the lock in complete darkness. With the sensor, you can set the backlight to turn on with the onset of twilight and the owner will arrive at an already lit area near the gate or in front of the garage.
• Energy saving. Residents of country houses often forget to turn off the light on the street before going to bed or leaving home. With a sensor this will not happen. The standard will turn off the light with the first rays of the sun combined with the motion sensor - as soon as everyone leaves the yard, and the programmable one at the specified time.
• Simulation of presence. Thieves do not risk to make their way into the house while the owners of the house, and the main sign of their presence is the switched on light. Street illumination with a sensor creates an appearance of presence and thus protects the house from vandals and robbers while the family is on vacation or on a business trip.

Light sensors have shown themselves well in urban lighting systems, they are often used by utilities, owners of shopping centers, car parks, billboards, etc. In private country houses, photo-relays are also beneficial and appropriate, therefore they are gaining popularity.

We choose a model of a photosensor taking into account technical characteristics

When buying, pay attention to:

• Voltage (volts). Manufacturers produce devices that are powered from a network with a voltage of 12V, 24V and 220V. We recommend choosing the latter, as they can be connected to the household network. For other devices, you will have to purchase voltage converters, which will make the designs more expensive and less reliable.
• Switching current (amperes). If this parameter is not selected correctly, the sensor service life will be significantly reduced. Therefore, with the number of lighting devices connected to the light switch and the type of lamps used (diode, housekeeper, incandescent), it is necessary to determine before selecting a sensor. To obtain the maximum switching current, the sum of the powers of all lamps should be divided by 220 (mains voltage). The number indicated in the passport of the device must be greater than the result of the calculation.
• Switch-on threshold (lumens). The parameter determines the sensor sensitivity to light. If the sensor is not sensitive, the light will start to turn on too early, and too sensitive will prevent the inclusion in the winter due to the reflection of light by snow. Look in the passport for the threshold adjustment parameters, the range should be 2-100 Lx or 5-100 Lx.
• On / Off delay (seconds). The adjustment range is also indicated in the instrument's passport. It should be possible to set a delay of 5-7 seconds so that the lighting does not turn off every time a car passes by.
• Power (wool). The smaller this figure, the more economical the device will be. In the device's passport the power consumption in the active phase (up to 5 W) and in the standby mode (up to 1 W) is indicated.
• Degree of protection. Since street lighting sensors are mounted in the open air, droplets and moisture vapor should not penetrate the housing, it should not be deformed due to ultraviolet radiation, etc. The resistance of the device to atmospheric influences must be IP44. If the sensor is placed in a protective box or under a canopy, the figure may decrease. If you select a model with a remote photo relay, the degree of protection can be reduced only for the photosensor, but not for the main unit.

If in your region very severe winters, pay attention to the operating temperature range, and if there is not enough space on the facade, give preference to compact models.

Varieties of light sensors

Usual inexpensive light sensors allow you to automate the lighting and adjust it to the duration of a light day. But since in this case the light burns all night, the manufacturers began to create models with more opportunities.

Among them:

• Photocell with motion sensor. Turn on the light, when in the controlled zone will start to move something. Thanks to the photosensor, the switch-on signal works only in the dark period. The device is inexpensive, reliable and compact. But if pets run around the territory, or if there are plant branches in the field of view of the sensor, there is a high probability of false triggering of the sensor.
• A photo relay equipped with both a motion sensor and a timer. The device can be finely tuned so that it only works when needed. For example, from 20.00 to 22.00 when the guest comes to the gate or the landlord returns.
• Relay timer. The device makes it possible to save electricity by switching off the light at an unused time. If the habits of the family are settled and tied to a certain time, this option can be very convenient. Many people prefer this type of device, since they do not have to be mounted outdoors, the timer can give a signal to switch on directly from the house.
• Programmable photocells. Devices of this type are the most expensive, but surpass other types in functionality. They make it possible to adjust the on / off lighting depending on the natural light, the time period, the day of the week, the season.

Optimal for the price and functionality are a day-night device with motion sensor and built-in timers. For the absolute majority of everyday tasks, the scenarios that they implement are quite enough.

Another approach to the classification of photosensors is the type of execution. Distinguish:

• Outdoor photocell. The device is installed on the street, most often - on the wall of the house. Such a photosensor must have a sealed casing and be made of thermo- and UV-resistant plastic.

  The outdoor photocell is fully sealed

• Photocell for indoor mounting. The device is mounted in the main electrical board of the house on a DIN-rail. A remote sensor is attached to it, which must be fixed on the facade and connected to the block by two wires. The requirements for protecting the main body in this case are reduced, but the photosensor must be protected from moisture and accidental shocks. Since for the laying of the wire will have to trowel the walls, the photo relay of internal mounting is better to install during the repair phase.

  The main unit and the remote sensor of the photo-relay for street lighting

If you have little experience in the installation of electrical appliances, or you are afraid of damaging the new wallpaper, it is better to prefer an outdoor photocell.

Manufacturers of photocells: countries and prices

The manufacture of such devices does not require unique equipment or complex technological processes, therefore, on a par with western products, the market offers many domestic photodetectors. At the same time, each country has both budgetary and inexpensive models with different degrees of protection.

Comparison table of photo-relays of different manufacturers

If you find a model with a suitable switching current, degree of protection and other parameters among the products of Russian manufacturers, you should not overpay for the German equivalent. But it is not worth saving too, as this will affect the longevity of the sensor.

IEK photo relay

In our country, the photo relay of the Russian manufacturer IEK is very popular.

Table of characteristics of photosensors of the brand IEK

All models of sensors of this brand are made of non-flammable plastic (polycarbonate), which protects the house from accidental ignition. According to their technical characteristics, the devices are suitable for Europe and the central Russia, except for very hot regions and the Far North.

Choosing a location for installation

If the sensor is not positioned correctly, the whole system will work inadequately. Therefore, the location of the photosensor must be located:

• far from high fences, trees, canopies and other obstacles to natural light;
• in a zone illuminated only by the sun's rays, and not by lanterns;
• away from flammable and flammable materials (in case of short circuit);
• on sites that are not exposed to chemical influences and mechanical shocks.

It is also desirable that the sensor is not too high, then from time to time it can be wiped from dust without using a ladder.

Connection diagrams of the photo-relay to the lantern

To install the sensor day-night, no specialized knowledge will be required, and tips are applied either to the package or to the device itself. Depending on the model, two or three wires come out of the photosensor body.

From the universal device comes three wires:

• phase (red, marking L);
• zero (blue, marking N);
• grounding (green, PE marking).

On a photographic example, it is evident that two cables must enter the device, each of them having three colored wires. Cable 1 is designed to connect to a light bulb. Its blue terminal is connected to the N terminal, and the red one is connected to the L terminal, similarly they are connected to the bulb holder. The grounding wire is connected to the green wire of cable 2 and fixed with a screw. Cable 2 is required to power the instrument, its red and blue wires are connected in the same way to adjacent terminals N and L.

There are models with two leads, there is no ground wire. Such photosensors are suitable for houses where the grounding system is equipped separately.

The connection method is even simpler, the incoming cable is connected to terminals L and N (phase and zero respectively), and only a phase cable is connected for the output. Zero is fed to the luminaire via the KM starter, past the photosensor.

If the photosensor needs to control several bulbs, you need to add a controller to it.

The controller is connected to the output terminals of the photosensor and adds another contact pair. With its help, the lamp can be connected in parallel, and not sequentially (as in a Christmas tree garland). The connection of several consumers through the controller makes the circuit more reliable and allows the lamps to burn even when one of them is out of order.

Video instruction for connecting and setting the photo relay

Manufacture by own hands

Having minimal skills of using a soldering iron you can assemble the simplest relay yourself. To begin with it is necessary to use the scheme with a minimum of components.

You will need:

• PR1 - photoresistor;
• R1 - electrolytic capacitor at 10K;
• VD1 KD522 - protective thermoelectric diode;
• VT1 and VT2 are transistors of the n-p-n structure;
• KT315B - transistor;
• K1 is an electrolytic capacitor per 1, 00 microfarads;
• К1.1 - the switch / switch;
• zero and phase conductors.

These parts can be bought in the store radio, or evaporate from the old unnecessary technology.

In this circuit, the transistors VT1 and VT2 form an emitter follower, due to which the signal from the photosensor is amplified and turns out to be powerful enough to open the electrical circuit. Thanks to the diode VD1, the reverse current flow is prevented. And the relay completely replaces the transistor cascade, used in more complex circuits.

To assemble a photosensor, it is necessary to consistently solder the legs of the elements used, or use a board with contacts. To make sure the product is working, it is advisable to check it on a stand with one lamp. In order to establish a suitable sensitivity of the instrument, it is necessary to solder a variable-sized resistor in the circuit. Change the resistance of the resistor until the device starts to give an on / off signal at the correct level of illumination (experiments can be conducted in the evening with lights off). Once the desired level of resistance is found, instead of an adjustable resistor, solder a constant. As the housing for the product, you can use a junction box for outdoor installation of electrical wiring, only in it you need to make a window for the photoresistor.

Since the relay allows the circuit to be used in a 220V network, it can be connected in the same way as the purchased one.

Video instruction for manufacturing a photosensor for diode lighting

Customize

If you bought the photosensor ready, you'll need to adjust its settings so that the light does not turn on too early and does not burn when it's already light on the street.

Looking under the cap of the photosensor, it's easy to notice the round handle, which turns the photosensitivity of the device. To start, set it to the far right (indicated by a minus sign). This means that to turn on the lighting you will need total darkness. Connect the sensor to the mains and at a time when you would like to turn on the streetlight, open the case and turn the lever until the sensor signals an on signal. Leave the lever in the same position and the system will always start at the same level of illumination.

Since the light reflected from the snow can cause the light to turn off too quickly for the winter, the light sensitivity of the sensor should be reduced, and in spring it should be increased again according to the described scheme.

In more complex photorelay with remote sensors, the on / off delay time is also adjustable. To change, you also need to switch the corresponding lever, only it does not rotate smoothly, but from one position to another. Positions and levers are signed right on the case, so there will be no problems with the settings.

Possible malfunctions of the mechanism for street lighting

If the photocell is not working properly, the reason is most likely due to installation or adjustment errors.

First, make sure that before the device day and night there was no street lamp, high fence, can tree since the installation was significantly higher, or began to shade the site more when it appeared on it leaves. Such barriers must be eliminated or the photo relay must be moved to a more suitable place.

It is also possible that one of the residents of the house accidentally changed the settings, or they became irrelevant with the change of the season. Follow the established light sensitivity and set the delay of operation for at least 5 minutes.

If a motion sensor has recently been added to the system, false inclusion may be attributed to the movement of pets or passers-by on the street.

When simple methods do not help, you need to look inside the device. It is possible that moisture has entered the housing and contacts have become oxidized, or as a result of a power surge in the network, one of the circuit board elements has burnt out. If the damage is not too significant, it is worth to take the device to the workshop and consult about the repair. But in case the board is noticeably damaged, it is necessary to replace the device completely (or only the remote sensor). In a self-made instrument, you should first check the quality of the soldering, and if necessary - replace the failed component.

When the device is fully functional and properly configured, the cause can be covered in the wires connected to it. Carefully check the integrity of the insulation on each section and replace the damaged cable if necessary.

In the event that the malfunction can not be detected on its own, it is necessary to contact the seller (if the device is under warranty) or the manufacturer's representative.

Is it worth using a photocell on its site

Table of advantages and disadvantages of day-night sensors

People who have already decided to install a photo relay on their site will never give up this device. After all, you only need to set up and connect it once, and the whole life of the day-night sensor properly turns on the light then and there, where it is convenient for the owner.