Which is better: resistive or capacitive screen? Types of touch screen. Touch water faucets: type of taps and characteristics

At first, touchscreens (touch screens) were quite rare. They could only be found in some PDAs and PDAs (pocket computers). As you know, devices of this kind never became widespread, since they lacked the most important thing, that is, functionality. The history of smartphones is directly related to touchscreens. That is why, nowadays, a person with a “smart phone” with a touch screen will not be surprised. The touchscreen is widely used not only in fashionable, expensive devices, but even in relatively inexpensive models of modern phones. What are the principles of operation of the 3 types of touch screens that can be found in modern devices?

Types of touchscreens

Touch screens are no longer too expensive. In addition, touchscreens today are much more “responsive” - they recognize user touches simply perfectly. It is this characteristic that paved the way for them to a large number of users around the world. Currently, there are three main designs of touchscreens:

Capacitive.
Wave.
Resistive or simply “elastic”.

Capacitive touchscreen: operating principle

In touchscreen designs of this kind, the glass base is covered with a layer that acts as a charge storage container. The user, with his touch, releases part of the electrical charge at a certain point. This reduction is determined by microcircuits that are located in each corner of the screen. The computer calculates the difference in electrical potentials existing between different parts of the screen, and the detailed touch information is immediately transmitted to the touchscreen driver program.

A rather important advantage of capacitive touchscreens is the ability of this type of screen to retain almost 90% of the original display brightness. Because of this, images on a capacitive screen appear sharper than on touchscreens that have a resistive design.

Video about capacitive touch screen:

The future: waveform touch displays

At the ends of the coordinate grid axes of the glass screen there are two transducers. One of them is the transmitter, the second is the receiver. There are also reflectors on a glass base that “reflect” the electrical signal that is transmitted from one converter to another.

The transducer-receiver “knows” absolutely exactly whether there was a press, as well as at what specific point it occurred, since the user interrupts the acoustic wave with his touch. At the same time, the glass of the wave display does not have a metal coating - this makes it possible to preserve 100% of the original light in full. In this regard, the waveform screen is the best option for those users who work in graphics with fine details, because resistive and capacitive touchscreens are not ideal in terms of image clarity. Their coating blocks light, which results in significantly distorted images.

Video about the operating principle of surfactant touch screens:

Past: about resistive touchscreen

A resistive system is ordinary glass, which is covered with a layer of electrical conductor, as well as an elastic metal “film” that also has conductive properties. There is an empty space between these 2 layers using special spacers. The surface of the screen is covered with a special material that provides it with protection from mechanical damage, such as scratches.

An electric charge passes through these two layers as the user interacts with the touchscreen. How does this happen? The user touches the screen at a certain point and the elastic top layer comes into contact with the conductive layer - only at this point. Then the computer determines the coordinates of the point that the user touched.

When the coordinates become known to the device, a special driver translates touches into commands known to the operating system. In this case, we can draw analogies with the driver of the most ordinary computer mouse, because it does exactly the same thing: it explains to the operating system what the user specifically wanted to tell it by moving the manipulator or pressing a button. As a rule, special styluses are used with screens of this type.

Resistive screens can be found in relatively old devices. The IBM Simon, the oldest smartphone known to our civilization, is equipped with just such a touch screen.

Video about the operating principle of a resistive touch screen:

Features of different types of touchscreens

The cheapest touch screens, but at the same time the least clearly transmitting the image, are resistive touchscreens. In addition, they are also the most vulnerable, because absolutely any sharp object can seriously damage a fairly delicate resistive “film”.

The next type, i.e. wave touchscreens are the most expensive among their kind. At the same time, the resistive design most likely belongs to the past, the capacitive design to the present, and the wave design to the future. It is clear that absolutely no one knows the future one hundred percent and, accordingly, at the present time one can only guess which technology has great prospects for its use in the future.

For a resistive touchscreen system, it does not make any special difference whether the user touches the device screen with the rubber tip of the stylus or simply with a finger. It is enough that there is contact between the two layers. At the same time, the capacitive screen only recognizes touches by some conductive objects. Often, users of modern devices operate them using their own fingers. Wave design screens in this regard are closer to resistive. It is possible to give a command with almost any object - you just need to avoid using heavy or too small objects, for example, the refill of a ballpoint pen is not suitable for this.

One of the latest developments from plumbing manufacturers is sensor-based faucets for sinks and sinks. They are equipped with an infrared sensor and supply water only when a person’s hands are within its sensitivity zone. Equipment requires batteries or access to electrical power to operate.

Touch faucets

Touchless touch faucets are convenient for use at home and public restrooms. The devices not only automatically supply, but also turn off water. This allows you to reduce utility costs. In addition, the faucet with a motion sensor is highly wear-resistant. Its monolithic metal body does not contain rotating parts or mechanisms that can fail due to intensive use. Additional reliability is ensured by high-quality installation. Thus, the HANSGROHE Focus 31174000 model is installed using SoftPEX hoses (especially durable hoses).

With each use, the touch-sensitive sink faucet supplies water at a comfortable temperature and pressure. These parameters are configured individually by the user. The ORAS ELECTRA 6150F model is equipped with a separate lever for this purpose.

Touchless sensor faucets are also convenient to use in the kitchen. They provide good water pressure and allow the housewife to free her hands. An example of such equipment is the KLUDI E-GO 422150575 mixer.

You can buy a touch mixer right now in the 220 Volt online store.

Every year modern plumbing becomes more and more functional. You can easily find a sensor faucet for the sink on the counters. Such devices themselves determine when water is supplied and turned off. This improvement significantly increases the comfort of using faucets of this type, and also makes it possible to significantly save water. Next, we will talk about what features a sensor water faucet has and the wisdom of its use.

The touchless sink faucet can be installed in any room where water is supplied. Typically, these rooms are the kitchen and bathroom. The principle of operation of a faucet with an infrared sensor is quite simple: the water opens at the very moment when a hand is brought to it. As soon as you remove your hand, the water supply will stop.

The IR sensor is triggered at a strictly defined distance. It is usually about 30 cm. Some devices have the ability to adjust the sensitivity distance of the sensor, so the infrared sensor can be adjusted to what is most convenient. It is also possible to determine the delay time, after what period of time the water will turn on and off after the hand is removed from the tap.

Please note: the fine-tuning function is usually present in models of expensive washbasin faucets (for example, Grohe Eurosmart Cosmopolitan E 36325000). If your choice is some budget option, you shouldn’t count on such improvements.

The touch mixer is designed to automatically supply water (using the operation of an electromagnetic valve) when hands and other objects enter its range of action. With this device, you can stop worrying about the tap being turned off while you are away from home. In addition, the water shut-off device is particularly reliable and prevents any leaks.

Many models of Grohe touchless taps allow you to adjust the water to the optimal temperature. Once you set up a water mixer with a motion sensor, you can forget about regular settings forever.

Design features of a mixer with an IR sensor

Externally, the touch faucet differs from its counterparts in the absence of unnecessary parts. The entire design is just a spout without any handles, valves or levers for supplying and adjusting water. The main difference between this device is the photocell and IR sensor built into the body.

The touchless faucet comes in two types of designs, depending on the type of sensor:

Device with an optoelectronic sensor. It is equipped with a photocell that reacts to the presence of movement in the work area. The sensor is usually located at the bottom of the spout. Based on the signal received from the photocell, the tap opens or closes. It is possible to adjust the sensitivity and time delay. Such devices are quite expensive, so they can be found quite rarely in everyday life. Also, during their operation, frequent false alarms were noticed.
Automatic device with infrared sensor. More common option. The principle of operation is to monitor changes in IR radiation with a sensor. When any object enters the sensor’s field of action, it measures the parameters. A command is sent to the infrared control unit to turn the tap on or off.

Water taps with an infrared sensor for opening water consist of the following structural elements:

IR sensor. It is located on the working panel of the structure, under the mixer.
A control unit that receives signals from the sensor.
A power adapter that provides constant power to the device.
Rechargeable battery (batteries) is used to control the device in the absence of electricity. Quite often you can find that power supply to faucets with an IR sensor is carried out only using batteries or accumulators.
Water filter. Water temperature adjustments.
Remote Control. Usually there are expensive models. Its presence in the package is not mandatory.

The water opens when the core is lifted by the membrane. Electrical voltage is supplied to the electromagnetic field zone, which affects the core. The check valve is used to prevent back flow.

Advantages and disadvantages of a touchless faucet

Advantages of a faucet with an IR sensor:

Hygiene. To wash your hands, you do not need to touch the valve with your hands. You just need to bring your hands to the tap. This is very convenient in places with large crowds of people. Naturally, a large number of people touching the tap leave a lot of bacteria on it.
Cranes whose operating principle is to use valves or levers fail faster due to rapid wear of the moving parts of the mechanism. Especially if they are located in public bathrooms. The sensor faucet does not have such disadvantages and can last much longer.
According to statistics, a touch faucet wastes 30% less water.
Operational safety. It is impossible to forget to turn off the touch tap. He will do it on his own. Based on this, we can conclude that the danger of a flood in your home has been prevented.
It is possible to adjust the water temperature. Moreover, the setting that you set using the regulator will not be lost. The next time you turn on the tap, it will provide water at the temperature you set.
The sensor faucet harmonizes perfectly with the design of any kitchen or bathroom. It will not only fit into the interior, but will also allow you to decorate it with its appearance.
Easy to care for. This device does not require frequent cleaning due to its minimal contact with users.

Despite the huge number of advantages, touch taps also have their disadvantages:

The price of such a device is quite high. Touch faucets are an order of magnitude more expensive than conventional lever faucets.
A faucet with an IR sensor is inconvenient to use in the bathroom due to the need to constantly keep your hand in the working area of the sensor. If you need to fill a bathtub or take a shower, this will be difficult with this device.
The disadvantage is also the presence of the same water temperature. In the kitchen, it is often necessary to have water at hand at different temperatures, which are intended for specific tasks. And constantly changing the adjustment is quite time-consuming and labor-intensive.

Advice: If you nevertheless decide to install such a faucet in the bathroom, let its installation location be only the washbasin. For a bathtub, the best option would be to use a conventional mechanical mixer, which will make it possible to use the shower normally or fill the bathtub without unnecessary problems.

How to choose a faucet with a sensor for a sink?

When choosing a faucet with a hand sensor, you should adhere to the following recommendations, which have been tested in practice:

It is best to purchase a faucet that allows you to adjust the delay time before and after the IR sensor reacts.
It’s good if you can configure the mixer’s IR sensor manually. This will make it possible to comfortably set the sensor response zone. By default, the sensor response zone is 30 cm.
The ability to adjust the water temperature is a must. It is recommended to purchase only those models that are equipped with an appropriate valve (Grohe Eurosmart CE with thermostat 36333000).
Select the model and color of the device so that it is in harmony with the surrounding interior. For example, if another faucet is installed in the bathroom, then it must be combined with the new device.
The sensor mixer is available for one or two pipes. That is, the first option can be connected only to hot or only cold water. In the second case, 2 pipelines can be connected to the mixer at once. If you have two supplies, cold and hot, of water, it is advisable to choose the second option.
It is recommended to give preference to well-known manufacturers, even if the equipment is more expensive (Hansgrohe, Grohe, Lemark, Oras, Bravat). This will reduce the risk of purchasing a low-quality product.
Pay attention to the cost. Most often, its size depends on functionality, appearance, dimensions, and technical capabilities.

The screens of modern devices can not only display images, but also allow you to interact with the device through sensors.

Initially, touch screens were used in some pocket computers, and today touch screens are widely used in mobile devices, players, photo and video cameras, information kiosks, and so on. Moreover, each of the listed devices can use one or another type of touch screen. Currently, several types of touch panels have been developed, and, accordingly, each of them has its own advantages and disadvantages. In this article we will look at what types of touch screens there are, their advantages and disadvantages, and which type of touch screen is better.

There are four main types of touch screens: resistive, capacitive, with the detection of surface acoustic waves and infrared . In mobile devices, only two are most widespread: resistive and capacitive . Their main difference is the fact that resistive screens recognize pressure, while capacitive screens recognize touch.

Resistive touch screens

This technology is most widespread among mobile devices, which is explained by the simplicity of the technology and low production costs. A resistive screen is an LCD display on which two transparent plates are superimposed, separated by a dielectric layer. The top plate is flexible, as the user presses on it, while the bottom plate is rigidly fixed to the screen. Conductors are applied to surfaces facing each other.

Resistive touch screen

The microcontroller supplies voltage in series to the electrodes of the top and bottom plates. When the screen is pressed, the flexible top layer flexes and its inner conductive surface touches the lower conductive layer, thereby changing the resistance of the entire system. The change in resistance is recorded by the microcontroller and thus the coordinates of the touch point are determined.

The advantages of resistive screens include simplicity and low cost, good sensitivity, and the ability to press the screen with either a finger or any object. Among the disadvantages, it is necessary to note poor light transmission (as a result, you have to use a brighter backlight), poor support for multiple clicks (multi-touch), they cannot determine the force of pressing, as well as fairly rapid mechanical wear, although in comparison with the life of the phone, this disadvantage is not so important, since the phone usually fails faster than the touch screen.

Application: cell phones, PDAs, smartphones, communicators, POS terminals, TabletPC, medical equipment.

Capacitive touch screens

Capacitive touch screens are divided into two types: surface-capacitive and projected-capacitive . Surface capacitive touch screens They are glass on the surface of which a thin transparent conductive coating is applied, on top of which a protective coating is applied. Along the edges of the glass there are printed electrodes that apply low-voltage alternating voltage to the conductive coating.

Surface capacitive touch screen

When you touch the screen, a current pulse is generated at the point of contact, the magnitude of which is proportional to the distance from each corner of the screen to the point of contact, thus, it is quite simple for the controller to calculate the coordinates of the point of contact and compare these currents. The advantages of surface capacitive screens include: good light transmission, short response time and long touch life. Among the disadvantages: the electrodes placed on the sides are not suitable for mobile devices, they are demanding on external temperature, they do not support multi-touch, you can touch them with your fingers or a special stylus, and they cannot determine the pressing force.

Application: Information kiosks in secure areas, at some ATMs.

Projected capacitive touch screens They are glass with horizontal leading lines of conductive material and vertical defining lines of conductive material applied to it, separated by a layer of dielectric.

Projected capacitive touch screen

Such a screen works as follows: a microcontroller sequentially applies voltage to each of the electrodes in the conductive material and measures the amplitude of the resulting current pulse. As the finger approaches the screen, the capacitance of the electrodes located under the finger changes, and thus the controller determines the location of the touch, that is, the coordinates of the touch are intersecting electrodes with increased capacitance.

The advantage of projected capacitive touch screens is their fast touch response speed, multi-touch support, more accurate coordinate determination compared to resistive screens, and pressure detection. Therefore, these screens are used to a greater extent in devices such as the iPhone and iPad. It is also worth noting the greater reliability of these screens and, as a result, a longer service life. Among the disadvantages, it can be noted that on such screens you can only touch with your fingers (drawing or writing by hand with your fingers is very inconvenient) or with a special stylus.

Application: payment terminals, ATMs, electronic kiosks on the streets, touchpads of laptops, iPhone, iPad, communicators and so on.

SAW touch screens (surface acoustic waves)

The composition and operating principle of this type of screen is as follows: piezoelectric elements are placed at the corners of the screen, which convert the electrical signal supplied to them into ultrasonic waves and direct these waves along the surface of the screen. Reflectors are distributed along the edges of one side of the screen, which distribute ultrasonic waves across the entire screen. On the opposite edges of the screen from the reflectors there are sensors that focus ultrasonic waves and transmit them further to the transducer, which in turn converts the ultrasonic wave back into an electrical signal. Thus, for the controller, the screen is represented as a digital matrix, each value of which corresponds to a specific point on the screen surface. When a finger touches the screen at any point, waves are absorbed, and as a result, the overall pattern of propagation of ultrasonic waves changes and as a result, the transducer produces a weaker electrical signal, which is compared with the digital matrix of the screen stored in memory, and thus the coordinates of touching the screen are calculated.

SAW touch screen

The advantages include high transparency, since the screen does not contain conductive surfaces, durability (up to 50 million touches), and surfactant touch screens allow you to determine not only the coordinates of pressing, but also the pressing force.

Among the disadvantages, we can note the lower accuracy of determining coordinates than capacitive ones, that is, you won’t be able to draw on such screens. A big disadvantage is malfunctions when exposed to acoustic noise, vibrations or when the screen is dirty, i.e. Any dirt on the screen will block its operation. Also, these screens only work correctly with objects that absorb acoustic waves.

Application: SAW touch screens are mainly found in secure information kiosks, educational institutions, gaming machines and so on.

Infrared touch screens

The design and operating principle of infrared touch screens is quite simple. Along two adjacent sides of the touch screen there are LEDs that emit infrared rays. And on the opposite side of the screen there are phototransistors that receive infrared rays. Thus, the entire screen is covered with an invisible grid of intersecting infrared rays, and if you touch the screen with your finger, the rays overlap and do not hit the phototransistors, which is immediately registered by the controller, and thus the coordinates of the touch are determined.

Infrared touch screen

Application: Infrared touch screens are mainly used in information kiosks, vending machines, medical equipment, etc.

Among the advantages we can note the high transparency of the screen, durability, simplicity and maintainability of the circuit. Among the disadvantages: they are afraid of dirt (therefore they are used only indoors), cannot determine the force of pressing, average accuracy in determining coordinates.

P.S. So, we have looked at the main types of the most common sensor technologies (although there are also less common ones, such as optical, strain gauge, induction, and so on). Of all these technologies, resistive and capacitive ones are most widely used in mobile devices, as they have high accuracy in determining the point of contact. Of these, projected capacitive touch screens have the best characteristics.

The text was prepared based on materials from open sources by Technological methodologists Karabin A.S., L.V. Gavrik, S.V. Usachev

Equipping a bathroom or kitchen with the latest innovations from the world of plumbing is not so much a tribute to fashion, but a reasonable approach to the consumption of natural resources. Therefore, to save money, you can use a sensor-based water faucet in your home, which will not only help you save money, but will also become a convenient assistant in your daily routine.

Peculiarities

The appearance of the touch tap raises an obsessive question - how to regulate the flow of water, turn the device on and off? Faced with this, future owners of this miracle of technology should know at least a minimum of information about the principle of operation of a touch-sensitive water tap.

The device is a monolithic faucet without any valves or other methods of regulating the flow of water. The action is carried out thanks to photocells and sensors of ultrasonic and infrared signals. They are the ones who detect the presence of foreign objects near the tap. All signal receiving components are installed in the crane itself. The signal is received in the so-called sensitivity zone, which is different for each device. Average sensitivity is approximately 25 cm. This means that the sensor will work when an object approaches it at a distance of 25 cm or closer. To regulate the water temperature, the touch faucet has special valves.

The device is powered by removable batteries, which last for approximately 2 years. After this, you can simply replace the battery and the faucet will work again. One battery lasts approximately four thousand starts.

A sensor faucet is a good water saver that will not let you forget about the water being turned on. He will turn it off himself when the owner moves away from the washbasin.

Operating principle of the device

The touch tap is driven by an induction sensor and a control unit. The sensor creates a magnetic field that detects any object entering its boundaries. When an object moves in the zone sensitivity the control unit receives a signal about the need to supply water. When the magnetic field no longer detects movement, the power supply stops the water flow.

The water supply is controlled by a solenoid valve. When motion is detected, the magnetic field applies an electrical voltage that affects the solenoid valve core. During the lifting of the valve core and its membrane, water is supplied. If the batteries are discharged and the signals weaken, the water supply will stop.

Available in two types depending on the type of food. Some can be plugged directly into an outlet, while others require batteries. For safety reasons, it is better to use taps with batteries rather than those directly connected to the mains.

Principle of operation

Installation steps

Advantages and disadvantages

Like any thing, sensory designs have advantages, but they are not without disadvantages. For better visualization, the characteristic can be presented in the form of a table.

Advantages	Flaws
Comfort and convenience are the undeniable positive qualities of the devices. There is no need to touch the surface of the gander with dirty hands and dirty it.	There are certain inconveniences when changing the water temperature, since this requires either reprogramming or turning the valve.
Touch water sources are the most hygienic because there is no need to touch the handles that many people have handled. It is for these reasons that such elements are installed in medical institutions, beauty parlors, and massage parlors.	An inconvenience when filling containers is that you cannot move away from the tap, otherwise the water supply will stop. It will also be inconvenient to use such a faucet in the bathroom if you need to fill the sink with water. In this case, it is more comfortable to use sensor nozzles to save water, which have a function to turn off the sensor.
It justifies itself as a water saver, since already in the first month of use the water bill will be significantly less than the previous figures in the payment bill.	A significant disadvantage for some families may be the high cost of such a device. In this case, a sensor attachment on the faucet to save water will help save the situation. Its cost is an order of magnitude cheaper than a touch tap.
There is no need to constantly think about whether the water is turned off.	Dependence on batteries or electrical network.
A sensor faucet that fits correctly into the interior creates a highlight in any bathroom or kitchen.	Devices for automated water supply with photocells can be triggered when exposed to light.
By using the software settings for the water temperature, you don’t have to worry about one of your family members burning your hands – this allows you to trust even children to use the tap.	—

As you can see, the advantages of sensor nozzles for saving water are much greater than the disadvantages. If we talk about the frequency of breakdowns, which was not included in the table, it is worth noting that touch-sensitive taps break down no more often than conventional faucets and if the tap breaks down, it will need to be repaired.

Types of sensor taps for water

According to its type, the water-economy is available in a variety of variants. According to the purpose of the design there are:

kitchen spouts with a swivel spout, for example for a sink;
for urinals - built-in or external;
for toilets that supply water after and for a certain time.

With swivel spout

For urinals

Based on their appearance, the following types of cranes are distinguished:

with built-in sensor and many functions and settings;
simple non-contact models with backlight.

Also, mixers are divided depending on the length of the gander, taking into account the type of sensor, and so on.

With sensor

When choosing a water supply device, you should pay attention to the following features of the model you like:

the ability to make settings at will (for example, you can adjust the sensitivity zone);
adjustment of the supply time (water is supplied a few seconds after raising your hands, which eliminates cases of accidental supply);
possibility of temperature adjustment;
the strength of the material from which the mixer is made;
appearance and harmony with the overall interior.

After purchasing the mixer, its installation does not cause problems. Most units are attached to the water supply connector in a standard way, so there are no difficulties. The mixer setup and rules of use are described in detail in the manual for the specific model.

Alternative option

The disadvantages of touch taps described above are tolerable, but undesirable. So that the housewife does not have to experience inconvenience with the supply of water and its temperature, American craftsmen offer alternatives to touch taps - touch nozzles. These attachments operate in a similar way to faucets, but they are attached to the gander itself, screwing into the thread. The advantages of such a nozzle are obvious:

by easily dismantling the nozzle, you can get a familiar faucet;
the price of nozzles is significantly lower than taps;
the nozzle operates using conventional batteries;
many models have the same functional settings as the faucet;
The attachment allows you to completely disable the sensor function.

Touch attachment

The only thing that can stop you from purchasing a nozzle is the appearance of the faucet after its installation. Often the attachments look a little rough, as they do not fit into the overall style of the room. However, with most of the positive characteristics of this device, many housewives neglect aesthetics, choosing, first of all, saving the family budget. And this is an important advantage of water supply devices - real benefits and savings.