When a private homeowner begins landscaping their property, they make sure the lights are turned on at night. It's important to turn off the power at dawn. There are currently two devices that offer this function: an astronomical timer and a photo relay. The photo relay has a simpler design, so it's often preferred.
Features of photo relays
Its main function is to illuminate an area when darkness falls. The photo relay controls the light intensity using a potentiometer. It also precisely records the time when the light sources should be turned on or off. Thanks to its convenient adjustment, the user controls the device's operation.
When light levels are low, the relay contacts close, turning on the street lights. When dusk dissipates, the contact circuit automatically opens, turning off the lights.
This operation depends directly on the photosensitive element. Light intensity fluctuates throughout the day. This phenomenon causes changes in the photocell's conductivity. Typically, this is a phototransistor or photodiode. The main component of the device is controlled by a dedicated control board. It ensures that the circuit's wires are closed.
The photo relay has undeniable advantages:
- When installing a motion sensor, electricity is saved;
- Electric lighting turns off automatically at dawn;
- You can control a group of lamps from one point.
Where can a device with automatic light control be used?
A photo relay can be installed anywhere. It's suitable for apartment buildings and private homes. It's often connected to lawn and garden irrigation systems. It ensures that the automatic watering system is triggered at the same time every day.
How to connect a relay
It can be connected to a wide range of devices. This determines its maximum operating load, which ranges from 1000 to 2300 watts. It operates on 220 volts AC, with a 10-amp circuit. The device's response threshold ranges from 2 to 2000 lux.
You may be interested in:When connecting a photo relay, you need to adjust the operating illumination. For this purpose, there is a special control at the bottom of the device. Operating illumination ranges from 5 to 50 lux.
You can adjust the device so that it turns on electricity in cloudy weather or in the shade. To do this, move the control knob toward the positive or negative side. Moving it toward the negative side will cause the relay to activate when it's completely dark.
What types of photo relays are there?
There are several types of relays with different elements. These determine the device's intended use.
A device whose shield contains a photocell
This type of relay turns on electricity when it gets dark outside. It turns off the lights when the sun rises. The device has a transparent housing made of durable material that protects the element from adverse conditions.
A relay that contains a photocell and a timer inside
In addition to the photocell, the device is equipped with a timer. The timer controls the lighting level at different times of the day. When a specific program is set, the photocell operates at a specific time interval. It activates when the lighting level falls below the set parameters. If the lighting level exceeds the set parameters, the output will be turned off.
You may be interested in:Timers are:
- daytime;
- night;
- weekly;
- annual.
Photo relay, the control of which allows you to adjust the response threshold
It operates on the same principle as the first two, but has a lever on the bottom of the housing. Turning the lever adjusts the response threshold. Turning the knob toward the "plus" side will activate the light in the shade or during a thunderstorm. Turning the knob toward the "minus" side will only activate the light relay in complete darkness.
A structure that contains a remote photocell
In this design, the photocell is located externally, not within the main unit. The unit must be mounted in an electrical panel. The purpose of the remote photocell is to ensure that the main unit is installed indoors, protected from vandals and inclement weather. The maximum distance between the relay unit and the photocell is 150 meters.
How to assemble a photo relay yourself using the diagram
Before installing the photo relay, make sure there are no shadows, trees, or other objects nearby. These may block natural light. The device's terminals are three different-colored wires, making them difficult to confuse. They are color-coded as follows:
- phase - black wire;
- zero - green wire;
- Switching to the light source is the red wire.
A junction box will help you connect all the wires correctly. Load switching is accomplished by interrupting the phase voltage and then resuming it. The green neutral wire supplies the power. Keep in mind that the relay's operating voltage rating is 230 volts, with a rated load current of 10 amperes.
If the load is high, a powerful switch will be required. It is designed for operation in twilight conditions.
A photo relay is a convenient and practical invention. It simplifies home and household management, ensuring comfort, coziness, and safety.