How to choose a light barrier for street lighting
Man has always sought to facilitate its work -invented the wheel, which allowed him to carry heavy loads without difficulty, then the car is able to move it in the space on a fairly long distances, washing machine, self-washed and spun things. It came even before the light on the street began to turn on and off as if by magic - at dusk light bulbs, and at sunrise - extinguished. This is due to a light barrier for street lighting, or as it is called - the twilight switch.
- The principle of photo-
- Driving a functional device
- Types of light barrier for street lighting
- Devices with photocell inside the body
- With the internal timer and photocell
- Relay with adjustable threshold
- A device with an external photocell
- Tips to help buyer
The principle of photo-
The principle of operation of photoelectric based on the workphotosensor which monitors the light level outdoors. This sensor can be remote, that is located outside the switch housing and the built (and photoelectric sensor is mounted directly to the switchboard). Remote photoelectric necessarily need to have a robust housing with higher rates on the level of protection from the environment and integrity.
Photo- and also equipped with a potentiometer,which allows you to accurately determine the threshold for switching on and off. And so the whole system has maximum protection against false positives (there are still bullies in Russia), in the light barrier is inserted into a special device from possible interference. Quality equipment, having all the certificates will be triggered only in the event that after the occurrence of the conditions of the exposed master will take a certain time.
Optionally you can set the range of thesensitivity to light, light barrier, which is most suitable to its conditions of accommodation. For example, if the light barrier is installed on the porch of the house and it's summer, it will be an excellent response range of the relay, which is available in the garage or in any other room. That is, the device can be programmed on the basis of light intensity.
The body is almost all built photo-switch that allows you to manually turn on and off the device, giving it thus a little "breathing room." And some models, among other things, equipped with a timer, trip relay at a certain (programmed) time that the equipment did not work in vain.
Driving a functional device
The figure shows a diagram of a light barrier for streetlight, which reacts to changes in light intensity. As the sensor is used LED, it works on the same principle as the solar cell.
LED (in this case HL1) - this isphotocell, generating a voltage proportional to the light intensity incident on the crystal. The circuit also has a DC power supply and R1-R2, which allows you to adjust the sensitivity of the light barrier, because the different LEDs of different sensitivity.
The resistor R2 adjusts the initial voltage VT1, integrable voltage generated HL1. It is this element allows you to adjust the threshold switching light barrier.
Types of light barrier for street lighting
Depending on the application and the specific photoelectric come in several forms:
- photoelectric photocell inside the body
- photoelectric photocell inside the body and timer
- light barriers with adjustable threshold
- light barrier with external photocell.
In addition, there are several types of equipment that is used in a fairly narrow industry sectors in the Far North.
Devices with photocell inside the body
This type of street light barrier allows you to includelight at nightfall and turn it off with the sunrise without human intervention. The housing unit, even though it is transparent, protects the cell from harmful environmental influences.
With the internal timer and photocell
This photocell for street lighting in addition to thethose advantages described above, has another distinct advantage - the ability to control the brightness depending on the time of day. With such a device, you can set the resolution of photoelectric work. The device will be included in the allowed time period, when the light level is below the value that was set. If the light level is above a predetermined value, the output will be off. Also, it will be turned off and if the timer is outside the allowed period.
Timers, in turn, also are different. Some devices are equipped with fluorescent timers, others - weekly and even yearly, and for the last relay allowed work time can be set for each day is different, or orient it for several days at once, for example, on weekends.
Relay with adjustable threshold
This type of relay has the same operating principle,as the previous two, but with the bottom side of the case he has a small "handle", which controls the rotation of the threshold triggering the photocell. If the controller is rotated in the direction of the plus, the luminaire will switch on even a small blackout, for example, during a lightning storm, or when it is cloudy. If you turn it in the direction of minus, the device only works when it is dark.
Thus, this device enables you to control the relay, depending on the time of year and weather conditions inherent to a particular locality.
A device with an external photocell
This device allows you to place a solar cell separately from the main block of the relay. Maximum distance from the first second may be as high as 100-150 meters. Sam unit is mounted in the switchboard.
Tips to help buyer
First of all, guided by their ownneeds and opportunities, and on the basis of the conditions in which you live. For relays with adjustable threshold - ideal for suburban areas, and for residential buildings. This device will allow significant savings on payment of utility bills for electricity, because it can regularly adjust depending on the time of year.
Relay with built-in photocell body goodso that it is easy to mount, and this event is not necessarily committing to electricians - to cope with the work will be able to virtually everyone. But the device with external light sensor will require some skill and some skills, but it is perfect for large-scale industrial plants, warehouses, and other similar establishments.
Relay with a timer, though is more expensive,will also significantly save on bills, because it can be programmed to suit your needs and requirements - the device will operate only when you want it, not when he wants the Sun and Moon. It will not only be included at the time, issued by you, but also to work in the mode you want.
Photo- - is a versatile instrument thatfrees your hands and thoughts. He will turn on and off lights, to respond to changes in light level, take care of your safety. In addition, the device can be supplemented by a motion sensor, which immediately "notify" the relay on the approximation of rank or intruder. This small detail will transform your home into a fortress, cozy and welcoming.