Motion sensor LED lights are one of the most important security measures for all outdoor walkways, garage areas, sides of any businesses, back door entrances, where it is necessary to install them. These lights will turn on only when any kind of motion is detected, thus ensuring they will scare off the intruders or light the way for the people who entering or leaving the premises.
By using less energy consumption and at the same time being super bright and powerful lights, you can ensure that you premises is not only well light, but quite safe. Nowadays for just about everything these motion sensor lights are used. Most of the office buildings, warehouse lights and also all parking lot lights are usually motion sensor equipped.
What Are Motion Sensor Lights?
These motion light sensors come designed with tiny lens which can detect any changes in the movement in any surrounding area. When switch of the motion sensor is turned on for the change in activities and heat conditions, then it will immediately activate the light. By utilizing certain automatic shut-off motion lighting feature can also be ideal when you need to conserve energy costs.
Usually most of the sensors available are infrared or IR. Few modern high end lights e.g. motion sensor UFO high bay lights normally use microwave sensors that are much more accurate as compared to IR.
You’ve all seen Motion Sensor Parking Lot Lights, usually in public buildings, at school or at work: they’re the ones that automatically turn on the light when someone enters a room. They are simple to operate, but use some rather special technology. Depending on the use, there are also several types.
To begin with, let’s see what about the most common sensors for parking lot lights, those with a white faceted ball (as in the header image).
The Passive Infra-Red sensor (PIR) is the most common type of presence sensor. Under the translucent plastic dome is a pyroelectric module the size of an LED.
These pyroelectric modules produce electric current when exposed to infrared radiation. They are a bit like infrared mini solar panels, although their operation is physically closer to a piezoelectric module, based on the variation in polarization of a material as a function of temperature (obtained by exposure to infrared.
The infrared source that activates the sensor can be a human or an animal: in fact, although they do not appear to glow in the dark, humans and animals emit infrared thermal radiation.
The presence sensor as a whole analyzes the current produced by the pyroelectric module. If it detects a sudden change, an infrared source has appeared, disappeared, or moved. The sensor then activates a switch, which turns on the light or triggers an alarm.
Note that the sensor is activated when the infrared to which the pyroelectric module is subjected varies. If you stand perfectly still in front of the sensor, it will not see you anymore.
So that’s how “passive” modules work.
There are also active ones: these, in addition to a pyroelectric sensor, have an infrared LED that sprays the whole room with infrared light. These have the advantage of working even if an object that does not emit infrared passes in front of the sensor. Indeed, passive sensors detect the infrared emitted by humans or animals. If you do not emit any, then it will not detect you. With a LED that sprays the intruder with infrared, the reflected/absorbed infrared will vary the signal which will activate the alarm.
Capacitive and inductive sensors
In addition to infrared-based sensors, there are other types with different functions.
The capacitive sensor works like a touch screen. It detects the small surplus of electrons at your fingertips, which are always slightly charged with static electricity. A mini-capacitor is created between your hand and the screen, hence the name “capacitive touch screen”.
A sensor using this technology can detect all objects moving within its range, simply by detecting the static charge carried by the object.
Inductive sensors, on the other hand, operate actively: they emit high-frequency electromagnetic radiation around them. When a metal component, such as a car, passes under the sensor, the steel frame of the car reacts to the electromagnetic field and emits its own field. This field is then detected. This system only works for metal parts.
This technology is also used in airport metal sensors and some supermarket anti-theft systems.
Inductive sensors are present at certain traffic lights on the road: not all lights are regular and some turn green only if a car comes along. The same applies to roads where the lights only come on if there is traffic: the detection of the car is done by induction.
In addition, it would even be possible, with such a sensor, to calculate the speed of a vehicle. This may be the technology used by speed lights, which switch to red if you drive too fast and to green if you slow down (even without stopping), but for an accurate measurement of speed, however, a laser radar or Doppler will be preferred (because it does not depend on the size of the vehicle).