The level of automation in a modern car differs significantly from a similar parameter in cars even from the eighties of the last century, but talking about older car models makes no sense at all. Today, if it starts to rain outside, smart electronics will automatically turn on the wipers or activate the windshield washer. If it’s evening outside the car, or you’re driving into a tunnel, the headlights will also turn on automatically. And essentially one device is responsible for this - a rain and light sensor.
We will tell you in this article what a rain and light sensor in a car is, how this electronic device functions, and what misconceptions exist regarding this sensor.
In fact, the rain and light sensor is really one electronic unit, which is located in the holder of the internal rear view mirror, on the windshield. Its functions are, in general, very simple. This includes turning the headlights on and off, as well as controlling the wipers, which on modern cars can operate in seven modes. Also, in some cases, the rain sensor can activate the windshield washer.
In principle, this device does not do anything that the driver himself could not do. And previously, it was the driver who turned on the headlights when it got dark and started the windshield wipers when water flooded the glass and visibility deteriorated. But, the development of the automotive industry is moving towards increasing driving comfort, as well as its safety, because to turn on the headlights or wipers, one way or another, even if for a split second, one had to be distracted. And at high speed, this can be fraught. In addition, sometimes the driver does not physically have time to turn on the lights or wipers, and by the time he is free, anything can happen. So it turns out that the light and rain sensor is not only comfort, it is also safety, albeit to a lesser extent. Therefore, when people say that installing such a sensor is pure marketing and another way to rip money off poor buyers, they are not entirely right. After all, driving an old-style car is radically different in comfort, ease and safety from driving a modern car. Another thing is that, with the same quality, older models are much more reliable and cheaper to maintain.
How the rain sensor works (dry and wet glass)
If we talk about the light sensor, then this is an ordinary photosensitive sensor that measures the intensity of the light flux, both around the car and directly in front of the car. Its task is to turn on the headlights in the following cases:
That's all, there's nothing special to say about this sensor. Another thing is the rain sensor. It consists of a special diode that emits a beam of infrared rays. The other part of the sensor is a sensitive sensor that records the intensity of reflection of infrared rays from the windshield.
The fact is that a dry windshield reflects most of the flow of infrared rays, while wet glass, on the contrary, transmits most of the flow of rays. It is this difference that the electronics registers and, based on the data received, gives a command to turn on the wipers.
The principle of the device is very simple and is found in one form or another in many devices, but the execution is much more complex and subtle. However, a light and rain sensor is not particularly expensive, and therefore today this device is found even in budget models cars.
In general, almost all misconceptions relate specifically to the rain sensor, since everything is more or less clear with the operation of the light sensor.
And so, there is an opinion that the rain sensor detects impacts on the windshield. But in this case, a simple question arises: why don’t wipers react to dust, insects and even pebbles, which sometimes leave noticeable marks on the windshield of our car?
The next myth states that the rain sensor cannot function at night. But, as you know, for infrared rays the degree of illumination outside does not matter.
They also say that in winter the rain sensor does not work. And here we need to figure out what the rain sensor does not respond to in winter? The sensor really doesn’t work on snowflakes, but if the glass is heated, and such glasses are modern models cars are becoming more common, the snow on the glass will melt and the sensor will work quite well for it. If your windshield is not heated, snow will probably not activate this sensor.
There are also misconceptions regarding tinting. At the very beginning, when such sensors were just beginning to be used, tinting the windshield made the sensor impossible to operate. Today, manufacturers simply produce tint films with special holes to ensure the functionality of the rain sensor. And in general, windshield tinting is a very controversial thing in terms of visibility and safety.
Modern cars are becoming more and more automated. The central computer controls almost everything: fuel injection into the engine combustion chamber, the operation of the brake system, and airbags, when it determines the strength of the impact received on the car. The automatic control and operation of the wipers, as well as the hatch door, were affected, which became possible thanks to the installation of a special rain sensor. What kind of sensor is this, how can I install it on my car myself and is it necessary to do it at all? Find answers to all these questions in the article below.
A rain sensor differs from conventional sensors in that it works not only as an electronic device with sensitive membranes. It also has an optical element that can react to the presence of moisture on the car glass. It is needed so that the car can automatically control the wipers and other car mechanisms that are responsible for closing the hatch and door glass. Since it is the atmospheric humidity that is important to the sensor, it is installed on the windshield.
But why do all this automatically if the driver himself, seeing raindrops on the windshield, can turn on the wipers and close the windows? According to the designers, such a system can significantly increase traffic safety in cars, since no atmospheric changes will be able to distract the driver from the road, because he will know that the car will do everything for him.
It is also worth noting that such a device is a fairly new invention, and previously it could only be found on executive car models. Today, such an innovation is becoming more and more accessible to ordinary car owners, and you can even install it yourself if desired (separate installations are sold for this).
Such a sensor consists of two main elements:
- emitter;
A small photodetector.
In order for the sensor to read correctly weather behind the car windshield, electronic components The emitter and photodetector have their own glass dryness and humidity parameters. Therefore, when a lot of rain drops appear on the glass, or it is stained with dirt, the sensor reads this as a change in the trajectory of the refraction of sunlight rays.
This condition of the windshield surface causes a corresponding reaction of the entire rain sensor system, as a result of which the wipers automatically turn on. At the same time, the intensity of their work is even regulated: if the glass is flooded with intense rain, the wipers will work very quickly and continuously, but if there are only small and lonely drops of rain, they will turn on at short intervals. The rain sensor is very sensitive, so even if a few drops of dirt get on the glass, the wipers will react almost instantly.
At the same time The sensor also has special requirements:
- when placed on the windshield, it should under no circumstances block the driver’s view, otherwise from a means that increases safety, it will automatically turn into a means that interferes with it;
The sensor must be located in the area of action of the brushes, that is, it must analyze exactly the area that the brushes can and should clean.
If you decide to buy a rain sensor for your car, keep in mind that its kit consists of a control unit and a relay. In this case, it will depend on the control unit whether the wipers will work at the right moment or not, since it is it that reads information from the glass and sends commands to other electronic devices of the car.
It is worth noting that It is not possible to place a rain sensor on any glass. The fact is that if there is at least one minor crack on the windshield, this may already serve as a reason for the sensor to turn on the washers and wipers, since it can recognize the crack as dirt on the windshield. You will also have to constantly monitor the condition of the wiper blades. The fact is that if they are in a worn-out state and are very poor at cleaning glass, the sensor will force them to work for a very long period of time.
As for the relay unit, which is also included in the rain sensor kit, this device is considered to be an executive device. It is the relay that controls the washer. But this is not the only function of the relay: thanks to this unit, the driver does not have to worry that due to a drop in energy, the rain sensor will burn out and fail. The relay can be located in any place convenient for the driver, but often it is mounted in such a way that it is as convenient as possible to connect power from the battery to the unit.
It is most appropriate to install a new rain sensor if your car already had such a device installed, but for one reason or another you decided to replace it. If the car does not have such a sensor, then the possibility of installing it on the car must be discussed with specialists. It is worth understanding that in some cases a rain sensor can play a very negative role for your safety.
But if you have weighed all the pros and cons, and as a result still came to the decision to install such a sensor on your car, then we present for you detailed instructions doing this kind of work for two the most common models of this device – RAINsensoe (RS-22) (American production) and DDA (Russian version).
Features of installing the rain sensor RAINsensoe (RS-22)
This option is almost universal, since it can be installed on any car whose electronics operate on 12 V. In order to install it on the windshield and connect to electronic system, necessary:
1.
Since this sensor model comes complete with a special holder, only the holder needs to be attached to the windshield. Often there is double-sided tape on it immediately, so after removing protective film, the holder will simply need to be pressed to the intended location on the glass.
2. A special gel, which comes with the device, must be applied to both working areas of the device body. It is necessary in order to equalize the refractive index of light rays and ensure the most reliable operation of the sensor.
3. Using self-tapping screws, which should also be included in the kit, attach the sensor body to its holder.
4. It is very important that after installation in work area there were no air bubbles between the sensor itself and the windshield that could interfere with its operation.
5. We connect the sensor to the car wiper mode switch. This should be done according to the following scheme:
- a blue wire is connected to the car body;
It is necessary to connect the red wire from the sensor to the “I” contact of the switch, having previously disconnected the yellow wire with a green stripe from it;
The wire disconnected from contact “I” must be connected to the yellow wire of the sensor;
We look for pin “53” with a blue wire on the switch block and connect the black wire from the rain sensor to it.
But keep in mind that this sensor model still needs to be configured to match the parameters of your car’s windshield. How to do this, read the instructions for the device.
Description of the procedure for connecting the rain sensor DDA
The Russian version of the rain sensor is slightly different from the one described above. In particular, when creating it, the designers tried to achieve the following goals:
- make a device that is as easy to use as possible;
The sensor is easy to install, allowing car enthusiasts to do it themselves without special experience;
The ability to connect the device without any interference with the integrity of the vehicle’s electrical wiring;
The ability to manually control the wipers in parallel with the operation of the rain sensor;
Affordable price for Russian consumers.
It is also worth noting that the Russian rain sensor is also capable of responding to the speed of the car - the lower the speed, the less intense the wipers will be. However, it is still better to use such a sensor only for cars manufactured by the Russian automobile industry. To install such a sensor, you will need to perform the following steps:
1. The rain sensor itself must be attached to the inside of the windshield. It can be attached either with double-sided tape or with a special fastening gel.
2. In the car's mounting block, you need to find a relay that is responsible for the operation of the wipers and windshield washer. This relay must be disconnected and removed from mounting block, and in its place install the relay block that comes complete with the rain sensor. When installing, it is very important to observe the required markings and the location of the key.
4. After the sensor is fully connected, it must be adjusted in accordance with the instructions.
Ideally, having a rain sensor on a car gives the driver many benefits. And first of all, the advantage of using it is that the device does not allow even small quantity moisture - it at the same moment activates the wipers, which remove everything unnecessary. Thus, the driver is constantly exposed to clean look on the road, and for this he does not need to press any levers or buttons.
But electronic device Human intelligence is not inherent, so very often the wipers are triggered randomly, which, on the contrary, can greatly annoy the driver while driving. Due to the high sensitivity of the rain sensor, it can be triggered even if air bubbles simply appear on the windshield, or if someone has left a fingerprint.
The only way to cope with false activation of the sensor is to thoroughly wash the car's windshield. In addition, you can also try to reduce the sensitivity of the sensor to this kind of “irritants” by adjusting it.
It is also worth mentioning that there are a lot of myths circulating among car enthusiasts, which have led to a slightly misconception about this device. It concerns the following functions:
1. Many car enthusiasts do not install a rain sensor on their car for the reason that they believe that it is supposedly incapable of functioning in the dark. In fact, this is not true. The sensor receives information about whether there is dirt on the windshield thanks to infrared rays, so the degree of illumination does not in any way affect the operation of the rain sensor.
2. There is a myth that a rain sensor cannot be used on tinted glass. This is also incorrect. The only caveat in installing a rain sensor on tinted glass is that it is necessary to make a small hole in the tinting film specifically for the device, which will not even be noticeable from the outside.
3.
The statement that in winter period It is generally better to turn off the sensor; it is also mythical. In winter, the rain sensor actually works a little worse, since such a device is primarily configured to remove raindrops from the glass, not snowflakes. However, if you additionally install a glass heating device, the rain sensor will work just as effectively in winter during snowfall as in summer during rainfall.
4. If for one reason or another you need to replace your windshield, this does not mean that you will have to buy a new rain sensor and reconnect it to the wipers and to the new glass.
If the old sensor worked properly before replacing the glass, then it can be replaced with a new one without any problems. In this case, new glass can be purchased with a special window for installing the sensor. It is also worth noting that if the sensor itself fails, only the device will need to be replaced; this procedure will in no way affect the windshield.
5. Another myth about rain sensors is that this device breaks down very quickly and for this reason you constantly have to buy a new sensor. Such a statement is again erroneous, although it has some basis. The reason for the lack of operation of the sensor may be its contamination: if a lot of condensation and dust have accumulated on its surface, they simply need to be removed, and the sensor will resume its operation.
Thus, a correctly installed sensor makes it possible to significantly increase the safety of driving a car, since it relieves the driver of responsibility for turning on/off the washers and wipers, as well as adjusting the position of the glass in the car doors and in the hatch opening.
Say what you want, but I really didn’t know how a rain sensor works in a car. If it was immediately clear about light - “some kind of photocell,” then about rain it’s more complicated.
When I recently switched from an old Nexia Daewoo to a new car, I was, of course, blown away by the presence of all sorts of sensors and amenities. I don’t touch the light at all - it turns on at any time of the day as needed by the light sensor. I don’t touch the wiper blades either - the rain sensor works very clearly. But how? I casually assumed that there might be a sensor somewhere for water flowing from the glass, but the brushes work even with small droplets. How else can you measure humidity on glass? Where is the glass interesting?
1 – rain and light sensors; 2 – rear view mirrors; 3 – zone of overlap of the windshield wipers; 4 – windshield
The rain and light sensor is designed to, when detecting moisture on the glass, turn on the windshield wiper depending on the amount of precipitation from the zero position to the maximum cleaning cycle, or turn on the headlights depending on the lighting conditions. The sensor is turned on by certain levers or switches.
The rain and light sensor consists of a combination of photosensitive elements and an LED. All parts are mounted on a board in the sensor housing. The optical element covers the sensor housing and the windshield. The job of the optical element is to focus and align outgoing and incoming light. The entire sensor is attached to the windshield using adhesive foil. To recognize rain, LED 6 and photodiode 8 are used. The principle of operation of the rain sensor is that the light emanating from the LED is partially reflected on the surface of the glass and, focusing through the optical element, hits the photodiode. If it's dry outside, all the light is reflected back and hits the photodetector (this is how the optical system is designed). Since the beam is modulated by pulses, the sensor will not react to extraneous light, like a TV that “does not see” someone else’s remote control. The degree to which light is reflected from the diode, and thus the amount of light that reaches the photodiode, changes if the glass is covered with water droplets or has a film of water. The stronger the humidification, the less the reflection of refracted light. Based on this, the output signal of the photodiode is used to determine the amount of precipitation. This is detected by the sensor, and the controller calculates the appropriate operating mode for the wiper. Response time for rain detection, i.e. The time taken between precipitation detection and the output signal to the wiper is less than 20 ms.
1 – windshield; 2 – light from a remote source; 3 – penetrating external light; 4 – raindrops; 5 – optical element; 6 – LED; 7 – remote photodiode sensor; 8 – photodiode; 9 – photodiode-external light sensor
For light recognition, a remote photodiode 7 and an external light sensor 9 are used. Sensor 9 covers the light conditions immediately spatially around the car and serves to automatically turn on the headlights, and the remote sensor 7 covers light conditions at a distance of up to three vehicle lengths in the direction of travel.
The system detects a general decrease or increase in illumination and switches the headlights on or off. From the difference in the signals from both sensors, the system can, for example, determine that a car is entering a tunnel and thus turn on the headlights no later than entering the tunnel. The logic of the system works in such a way that the light is turned off only when the light sensor detects sufficient illumination. If, in addition to light detection, rain detection is also active, the system also switches on the headlights in heavy rainfall.
1 – analysis of external illumination; 2 – analysis of illumination difference; 3 – analysis of remote illumination; a – the difference in illumination is less than the value of the switching threshold, the light is off; b – the difference in illumination is greater than the value of the switching threshold, the light is on
We have already dispelled myth No. 1: the rain sensor is NOT activated by the impact of drops on the glass, as well as vibration and other mechanical influences. The operation of the rain sensor is based on the action of photocells. If the sensor responded to shocks, the brushes would diligently wipe flies, mosquitoes and small pebbles from the glass.
Myth #2: “The rain sensor does not work at night.” As we have already found out, the operation of the rain sensor is based on the principle of reflecting infrared rays. Their properties do not depend on illumination. Otherwise, for example, remote controls remote control didn't work in the dark.
Myth No. 3: “When replacing glass, you will have to say goodbye to the rain sensor.” You don’t have to: many manufacturers offer car windows with space for a rain sensor. For example, at the Olympia company you can purchase rain sensor glasses for most foreign cars: Toyota Camry, VW Passat, Audi A4 and other cars.
Myth #4: “You can’t put a tint strip on a windshield with a rain sensor.” You can: in this case, a hole is cut out in the tint film for the sensor. The main thing is that the glass tinting is done in accordance with GOST.
Myth #5: “A rain sensor is useless in winter.” Since the rain sensor works by reacting to water drops and not snow, it functions less well in winter. However, if the car has heated glass, falling snow will immediately melt into water, and the rain sensor will work normally.
General Motors conducted the first experiments on creating rain sensors back in the 1950s. The sensor was created for the iconic model - Cadillac Eldorado. But the technology was far from perfect: between how the rain sensor works on a modern car and the first experiments of GM engineers there are decades of design development.
One of the first production cars with a rain sensor was the Nissan Silvia, a sports coupe. In the 2000s, rain sensors appeared on cars from Volkswagen, Cadillac and other leading manufacturers.
Rain sensor operation is used not only in the automotive industry, but also in agriculture, to control the irrigation system. - “Field” sensors have a different operating principle than automobile ones: they have hygroscopic disks, which wet They increase in size and shrink when dry. This regulates the water supply. Interestingly, some sensors have a built-in temperature indicator that stops water flow if the temperature drops below zero.
Modern cars are literally packed with all kinds of electronics. Some devices are designed for our entertainment, others are designed to increase comfort, and others are additional.
But do we really need them? Everyday life? Or is their real goal to extract more money from the potential? We'll talk about the rain sensor. Many drivers consider it almost a mandatory option for all cars without exception, while others can easily do without it, operating the windshield wiper mechanism with their own hands. Let's weigh the pros and cons.
The rain sensor is an optical-electronic device installed on the inside, next to the rear view mirror. The design consists of an LED and a photodiode. The principle of operation is quite simple: the LED emits light invisible to the human eye, which is partially reflected from the windshield and returns to the photodiode, which, in turn, determines the degree of moisture in the glass. The device’s program includes light refraction parameters for dry and wet surfaces, thanks to which the sensor determines when the wipers should be turned on.
The bottom line is that if the glass is dry, then it returns to the receiver a large number of Sveta. If the glass is wet or dirty, less light is returned and sends a command to clean the glass.
The rain sensor kit consists of a system control unit and a relay unit. The device of the first one is a combination of an LED and a photodiode. The relay block is the executor in the system and is responsible for directly controlling the brush mechanisms. In addition, it protects the system from voltage surges and interference. It is installed where it will be convenient to supply power.
Some sensor models are capable of not only controlling, but also automatically closing the side windows and sunroof. And this ability is fraught with hidden danger. Many people like to hold onto the top door frame while driving. And if they have a rain sensor, they should be careful that the rising glass does not pinch their hand or fingers.
It is also necessary to take into account the fact that installing the device imposes special requirements. If the glass has scratches, chips or other damage, this may incorrectly affect the operation of the sensor, since the light passing through the glass can be distorted and refracted, misleading the system.
Also, the disadvantages include false operation of the wipers even in dry weather. This is possible in cases where there are fingerprints or other minor stains on the glass. In addition, you will have to get good brushes to ensure.
And further. It is necessary to use the products extremely carefully, since moisture getting inside the control unit is extremely undesirable. In this case, the rain sensor may need to be replaced. You'll also have to say goodbye to windshield tinting, as it blocks infrared rays and interferes with the system's operation. The problem can be solved by a small hole in the film exactly opposite the diodes.
Myth No. 1: “ The sensor does not work at night».
No matter how it is! Did you know that infrared rays don’t care about illumination? They feel equally good both during the day and at night.
Myth No. 2: “ The device does not work in winter».
Partly yes, since it is tuned to water, not snow, and the degree of refraction of light is different. But if it is a windshield, then there will be no problems.
Myth No. 3: “ If the glass breaks, then you can say goodbye to the sensor».
No, you just need to replace the glass with the same one that has a mounting location for the sensor.
Myth No. 4: “ If the device stops working, you need to change the windshield».
Wrong. If the device does not work, then most likely the problem is dust and condensation on the diodes. It is enough to remove the sensor and... But there's a problem. It consists in what to glue the sensor onto. This requires special double-sided transparent tape, and the process itself is very complicated. For this reason, installing a rain sensor yourself is not recommended. The most the right decision will contact a specialized service, where they will provide you high-quality repairs device
This is more a matter of taste than invaluable benefit. The Internet is replete with articles about how useful and indispensable such devices are. That today's drivers are tired of moving their fingers and turning on the wipers. That they are very distracted by this second action. One gets the impression that this is written by people who themselves have never sat...
Video on how to install a rain sensor:
You can't argue that there are situations on the road when electronics can really help. For example, when you are driving along a narrow road and an oncoming car splashes you with mud. Or when on a rainy day you are driving along the highway and overtake a long truck, from under the wheels of which kilograms of water are flying onto your windshield. At such moments, a rain sensor can really be useful. The device is capable of reacting not only to moisture on the glass surface itself, but also to drops at some distance from it, which ensures prompt activation of the windshield wipers.
Ultimately, it's up to you to decide whether to trust the electronics or personally control the windshield cleaning process.
P.S. Write to us in the comments, is your car equipped with a rain sensor? If not, would you like to have such a device on your car?
Everyone is already accustomed to the fact that in a modern car there is a lot of incomprehensible and difficult things from the point of view of understanding of the common man in the street. Motorists are divided into two camps: those who are trying to understand the structure of “all this” and those who are indifferent to all this, since there are specialists who “know what’s what”...
I rather belong to the first type of people and try to at least superficially delve into the structure and principle of operation of this or that unit, so that in case of an unforeseen situation I have an idea of what is happening with my car or at least understand when they try to help me at the service station to cheat, “selling me some kind of game” veiled under clever words and terms... :)
In my article today I want to talk about a rain sensor, which is also sometimes called a rain sensor, how it works, what it is, how it works, and the myths that surround this device. Interesting? Then let's go!
As the name suggests, the rain sensor has something to do with precipitation, namely rain. That’s right, this sensor, unlike other sensors that a modern car is stuffed with, is responsible for timely automatic switching on wipers. That is, as soon as this sensor detects that there are drops on the windshield, the wiper blades immediately turn on and the glass is cleaned.
But how does this magic happen, you ask? I, and you, probably, have puzzled over this more than once and tried to explain the principle of operation of a rain sensor by the presence of some sensors that are triggered when interacting with moisture or something like that... But in reality, everything is not so The rain sensor works on a completely different principle.
Typically, such a sensor consists of several photosensitive elements (photodiodes) and LEDs that work in tandem. The sensor itself is a small circuit board enclosed in a plastic case. All this equipment is attached in the area of the interior rearview mirror, or rather in front of it. The sensor is located in the passenger compartment and is attached to the windshield using sealant or an alternative adhesive.
The operating principle of this sensor is based on the law of light refraction. Built-in LEDs emit infrared light that passes through the windshield and is reflected from the outside of it. The reflected signal is then captured by a photosensitive element or photodiode, which analyzes the quality of the received signal. If the signal received by the photodetector is clear and strong, the wipers do not turn on, since a special controller “understands” that the glass is clean and there is no need for “cleaning”. If the glass is covered with raindrops, the signal sent by the LEDs will begin to refract and return with delays and a completely different content. In this case, the controller concludes that the glass is covered with raindrops and, guided by certain algorithms, turns on the wipers at a certain frequency. The heavier the rain, the more the signal will be scattered and the less signal the photoreceiver can receive, therefore, the more intense the wiper blades will work. Thus, regardless of the intensity of rain, the glass will be cleaned effectively.
This is the simple principle that the rain sensor works on. More advanced sensors are capable of analyzing not only precipitation, but also the degree of illumination, and turning on the headlights if necessary.
And now, as I promised about the myths that surround the rain sensor, also known as a rain sensor.
Myth one : “The rain sensor doesn’t work at night!” This is not true, since infrared sensors do not need light to operate, and they do not depend in any way on the degree of illumination environment. For example, let's take any control panel that works using the same technology. As we know, he doesn’t give a damn when he switches channels, day or night he works properly!
Myth two : “If you replace the windshield, you’ll have to say goodbye to the rain sensor!” As a rule, most car manufacturers, if not all, when producing glass, take into account the likelihood that you will want to install a rain sensor or you already have one installed. Therefore, special “windows” are provided on the glass for this type of device.
Myth three : “The rain sensor is useless in winter!” Perhaps this is partly true, the sensor really does not respond to snow. But as we all know, snow, falling on the warm glass of a heated car, will certainly melt and turn into water, which the sensor can easily detect and take measures to eliminate. If the windshield is cold, then most likely there is no one in the cabin, which means there is no need for wipers. In all other cases, the temperature in the cabin during snow will be higher than outside and the windshield will somehow be warmer than the environment, which means the snow will melt and the rain sensor will work, and with it the wipers.
I will end here. Thanks to everyone who read to the end! I look forward to your feedback on this invention, as well as comments on the topic: “What is a rain sensor for you: a fashionable feature or a useful and necessary thing?. All the best and see you at .
