There are two types of twilight sensor: electric and electromechanical. The twilight sensor is an accessory widely used in the garden thanks to its operating system: it is activated before sunset and deactivated before dawn. On the back installed a small photosensitive panel that is able to detect the percentage of brightness present in the environment in which the sensor is installed and therefore to activate (or deactivate) the power supply circuit of the light cell. Some twilight sensor models can also be programmed to turn on and off according to your needs. The latest models also allow weekly programming in addition to the daily one. This extends the life and efficiency of the sensor and avoids switching on during the day in the presence of atmospheric conditions that reduce the real brightness.
The external twilight sensor is a product easily available on the market and present in various shapes and sizes. The most commonly used are those with 220 volts powered by electricity and those with 12 volts batteries. The first type of external twilight sensor allows you to create extremely suggestive illuminated points within your garden. By passing the electric cables, flowers and plants will shine even during the night. The 12 volt external twilight sensor is suitable for small gardens, because the brightness is much less intense. The operation takes place thanks to the external batteries that must be checked periodically (especially in summer) to avoid the leakage of corrosive acids that damage the sensor. Both types of external twilight sensor can be programmed to allow greater energy savings.
The rechargeable twilight sensor uses solar energy to recharge itself. The environmental impact does not exist, on the other hand the performance is high. The rechargeable twilight sensor is mounted on medium-sized LED lamps that are usually positioned to furnish open spaces where the electricity network does not reach. The small photovoltaic panel installed captures the sunlight and stores it in a package intended for battery power. Thanks to this system, during the night hours it is possible to admire splendid design buildings powered by sunlight. Usually low consumption lamps are used as the atmospheric conditions are not optimal in all areas. The voltage ranges between 0.9 and 1.9 volts, and a single battery guarantees constant lighting throughout the night.
The proportional twilight sensor has larger dimensions and generates a direct light beam. The brightness increases gradually and inversely proportional to the amount of light received by the sensor. It is used to illuminate a single point, in fact sensors of this type are found above all in areas very far from inhabited centers not reached by public lighting. This sensor is much more complex because it has a “dimmer” that regulates the power of the brightness absorbed during the day. A device of this type can cost as much as 80 euros, about 60 euros more than the normal twilight sensor. To avoid wasting energy, a twilight switch can also be installed to manually activate the sensor and not find nasty surprises on the electricity bill.