Monday, 31 July 2017

Membrane or Touchscreen?

Membrane switches have for many years been the dominant choice as the method of machine control in a multitude of industries. However, in the last decade, touch screens have been slowly transferring their prominent position in consumer products into the Human Machine Interface (HMI) market. With the advent of Industry 4.0 and the IOT, which direction will machine manufacturers take for their next input system?  

Membrane switches were invented more than 40 years ago. They first appeared in the late 1970’s as a low-cost method of inputting data into toys and keyboards. The very first switches consisted of two thin layers of plastic, these were printed with a conductive ink and separated by a spacer layer of adhesive, a decorative screen printed top film then adhered to the switching layer. When a key was pressed the two conductive layers would touch, allowing a voltage to flow.

The first switches were initially labelled as unreliable, with brittle materials that would crack or turn yellow after time. These switches also lacked any tactile feedback and were prone to inconsistent contacts. However, some enterprising individuals saw the potential in this new technology and formed companies in order to focus on manufacturing these new input devices.
Within only a few years these companies had developed new materials and processes that had eliminated all of the early problems and a new generation of membrane switches emerged. The new switches were reliable, had a customisable tactile feel, embossed or domed graphic overlays and resistance to harsh environments. Over the next 30 years a host of options and variations were added, such as a range of finishes, integrated LED, large area backlighting and anti-microbial coatings all of which increased the range of potential applications even further. The offer of a fully customisable product with a low cost and fast turnaround was difficult to resist and the membrane switch quickly became the technology of choice for HMI devices across a multitude of industries.      

However, by the 1990’s a change was on the horizon and touchscreen technology was arriving in HMI devices. Touchscreens are not new, in fact, they are older than membrane switches! The first finger driven touchscreen was invented by E.A. Johnson at the Royal Radar Establishment in Malvern, UK in 1965 and touchscreens were in use in some machine terminals by the 1970’s. The first touch screens were made with resistive technology. Resistive touchscreens have 2 layers of a clear flexible material coated in a clear conductive material which when pressed together by a finger would allow a voltage to pass, the resistance of this voltage could be measured to indicate the position of the finger on the screen.

The 1990’s saw the first widespread use of resistive touchscreens, these were in the first personal digital assistant or PDA and tended to use a stylus instead of a finger to push the conductive layers together. The first of these consumer touch applications suffered from slow software and poor display attributes, however, resistive technology was now firmly on the radar of the HMI market and the first resistive products started to appear that controlled machines.

The 2000’s saw the introduction of a new capacitive touch technology, this worked not by applying pressure to the screen to make a contact, but by sensing changes in the capacitance of its surface. As no switching pressure was required, this meant the top surface no longer had to be flexible but could be hard and flat, making glass a perfect choice as a top surface. No switching pressure also meant that no moving parts were required so long life and reliability were guaranteed. Public awareness of this new technology was captivated by the apple iPhone. Using capacitive technology, it revolutionised input systems for mobile phones by replacing numerous silicon keys with just one capacitive touch screen.            

For the HMI market, forward thinking companies who had already embraced resistive touch screens began to adapt capacitive technology into the larger sized screens that would be required to control machines. The new technology offered many advantages over resistive screens such as multi-touch and the ability to swipe across the screen. 

Today the change from membrane technology to capacitive technology for machine control is rapidly gathering pace. The onset of the IOT and industry 4.0 requires the machines of the future, whether they are controlling a production line in a factory or controlling a life critical function of a patient in a hospital, will have to be “smart”. They will empower machine operators with not only live information but also predictions enabling them to take crucial decisions to produce optimal outcomes. These decisions and information exchanges will often be carried out in a live networked environment.

A customised touch screen is the perfect solution to control tomorrow’s machines. A large display with an interactive capacitive touch allows a symbiotic relationship between machine and human, this grants both the ability to transfer and receive information quickly and accurately. As the future unfolds and new needs and requirements become necessary, the information and controls can be easily changed by a software update, therefore, making the input system completely future proof.

Membrane switches will always have their place, but the machine control of the future is a touch screen.

Andy Stevens is the commercial manager for SCHURTER Electronics Ltd in the UK and has worked in the HMI industry for more than 25 years.

SCHURTER Electronics was a founding member of membrane switch technology and one of the first manufacturers of resistive touchscreen technology. Today it is leading the way in the capacitive touch systems of the future and offers its customers the solutions they require to grow in their markets. 

Monday, 24 July 2017

Why screen printing can make your product stand out?

So, you need a visually attractive product that has strong and bold colours, and that also stands out from the crowd? You can make your product stand out if you make use of screen printing in the production of your products.

Below are 3 points that show why screen printing is still number one.   

Cost effective 

The consistency and reliability of screen printing equipment make them more cost-effective when facilitating a long run or complex graphic prints. The most time-consuming aspect of screen printing is the setup. This can take some time to make sure it is all positioned and printing correctly, and once the setup is complete screen printing can provide consistent high-quality prints over long runs. 


The way Screen printing can be used on a variety of different materials and surfaces, and that we can choose from an abundance of special inks, are all reasons that show why Screen Printing is the best method for creating products with unique features. This is a very flexible and versatile printing technology.


The durability and vibrancy of screen printed parts can make a product stand out. Producing superior image resolution and more attractive colours also make screen-printed graphics much more durable and resilient than other processes. Because of this screen printing is a better option for products that come into contact with harsh environments, as well as all weather conditions.

So there you have it, three quick points to why screen printing is still number one. If screen printing is the route you want to follow then please contact us at SCHURTER we will be more than happy to help.

Tuesday, 18 July 2017

Multicolored Illuminated Piezo Switch

Today, SCHURTER's piezo switches are used in many applications, especially in harsh environments. The advantages of using a piezo switch are many, but one of the key benefits is their completely sealed surface, which can be activated by applying minimal force to signal actuation. These switches are now offered with a new multicolored illumination.

The pulse derived from the force exerts pressure on the piezo element, thereby converting the physical pressure into an electrical potential. This pressure is sufficient to produce a clear, potential-free signal, which is possible with the employed semiconductor components. Because of the sealed surface, the product has IP69K seal and thus is absolutely impervious to leaks.

Unlike pushbuttons with a mechanical stroke, no dirt can accumulate underneath or around the switch. This technology is ideal for hygiene related applications such as those in medical, the food processing sector and outdoor applications.

The new multicolored illumination of the PSE series greatly expands its application range. The round button style switch is available with 22 mm, 24 mm, 27 mm and 30 mm diameters. To make the integration into customer specific applications as easy as possible, the strands are color-coded in each of the illumination colors and are supplied with a voltage range of 5 to 28 VDC providing a brightness that remains constant in all applications. The standard version is offered in red, green, and blue. Additional color options include yellow, cyan, magenta and white, which can be made through additive color mixing.

Upon customer request, the supply voltage as well as the internal resistors can be removed. This creates the opportunity to present a broad color spectrum, which requires the addition of a microcontroller in the application to control the LED's. In addition, there is the possibility of varying the brightness depending on the design, which allows dimming.
The multicolored illumination also allows multicolored colored status indications. Today these are used in customer-specific applications, e.g. in locked access areas to laboratory rooms.

With this traffic light display (red, green, yellow) it is intuitively understood if one can enter the laboratory, if the room is currently occupied or if the room is being cleaned. Thus the SCHURTER PSE switch becomes an interactive input element that, at the same time, is a status indicator via the ring illumination.

The PSE series is available in several versions. These range from a "marine grade" stainless steel housing to anodized aluminum housings in various colors.

Additional Versions:

As an alternative to the multicolored expansion, the PSE series is also available in the "EX" version with ATEX certification for applications in potentially explosive areas, which are used especially in environments with gases and flammable liquids, such as in the petrochemical/gas industry.

Another specific version, "PSE HI", has an IK06 rating for applications at risk of vandalism, which, in combination with a piezo element, is the only one currently available on the market.

In summary, the SCHURTER PSE metal line switch family is ideal for applications where hygiene, cleanability, visual feedback or use in a harsh environment are of key importance.

Visit our website for more information

Monday, 17 July 2017

Protection against thermal runaway

A thermal runaway is an increasing threat to electronic devices where more and more power is packed in ever smaller spaces; it is a threat that is poorly dealt with using traditional means. SMD thermal fuses offer a solution that can be reflow-soldered at 260°C and still open at 210°C.

What is meant by a thermal runaway or the thermal damage of power semiconductors: A thermal runaway refers to the overheating of a technical apparatus due to a self-reinforcing process that generates heat. This damage usually causes the destruction of the apparatus and often leads to a fire or explosion.


The causes of a thermal runaway are varied and often random in nature. However, the ever-higher power density in electronic wiring and the trend towards miniaturization are without a doubt of particular importance. More and more functions are packed in compact modules, which then also have a correspondingly high power consumption. Even slightly excessive currents in power electronics with only a little power loss lead to elevated temperatures of approximately 200°C. The possible consequences: damage or disconnection of surrounding components, damage to the printed circuit board structure or, in the worst case, the triggering of a fire.

Build up

With a power semiconductor (e.g. MOSFET) the drain-source transmission resistance increases with rising temperatures, when connected, which results in an increasing loss of power in the barrier layer. If the elements are not sufficiently cooled - the high power density permits cooling - the power loss output in the form of heat can no longer be sufficiently dissipated, which also increases the transmission resistance. This process escalates and ultimately leads to destruction of the component.

How to protect against a short circuit? The cooling of a system must dissipate at least as much energy as it is supplied with. The overcurrent during a thermal runaway is too low to cause a conventional fuse to trip. Thermal circuit breakers or PTCs would, in principle, be used, but the products available for the assembly of an SMD printed circuit board are too complicated or completely unsuitable


SCHURTER develops and manufactures SMD thermal fuses with the lowest possible internal resistance for power electronics of the highest packing density. They can be reflow-soldered at a maximum temperature of 260°C without opening. The temperature trigger is therefore around 210°C during operation. This corresponds to a range above normal component temperature ratings, but still below the limit to create serious consequences, The fuse opens with or without current flow depending on the temperature. Such irreversible thermal fuses are resistant to mechanical shock, vibration, thermal shock, temperature cycles and moisture. They are qualified according to AEC-Q200.

Visit our website for more information

Download the whitepaper

Thursday, 13 July 2017

What you can gain from using a graphic overlay?

What you can gain from using a graphic overlay?

If you have a product but need a smart user-friendly front display, then graphic overlays will be the answer. SCHURTER has been designing and manufacturing graphic overlays for many years, for a wide range of businesses in various sectors. Below you will find four points that show what you can gain from using a graphic overlay.


The importance of quality, robust material is ever present when producing a graphic overlay. This allows them to be used in any environment that they could be exposed to.


In brief, graphic overlays can be customised in any way you want. The amount of choice you have is limitless. Potential customisable features include textured surfaces, embossing, adhesive choices and even brail. These choices are important as the overlay should look appealing, but also provide textural context to the user. One of the most crucial parts of designing the graphic overlay is the ink and colour choice. To decide what colour, we at SCHURTER use a spectrophotometer which is a device that's connected to a computer. This measures the colour electronically and takes very sophisticated readings of the values which it then breaks down to show what amount of colour is needed to create the Pantone or RAL reference you require. We can also match colour swatches from samples. It means we can create very accurate colour matches for your graphic overlay.


Graphic Overlays attach easily to many surfaces by using adhesives. These make it quick and simple to apply and you can be safe in the knowledge that it will stay fixed down. We have a great knowledge on adhesives and we can recommend the best one for your products.

Easy to clean 

Being easy to clean is sometimes overlooked, but with certain products hygiene is key. For example, medical equipment needs to be constantly clean. SCHURTER understands what the medical market demands, we offer easy to clean antibacterial coatings and resistance against chemicals and solvents.

If graphic overlays is something you think your Company needs then look no further than SCHURTER Electronics Ltd

Wednesday, 12 July 2017

Fuses for the automotive industry according to AEC-Q200

In recent decades, cars have increased in numbers as well as dimensions. They have become more comfortable, more powerful, safer and therefore heavier as well, with mid-range cars already weighing 1.5 tons. It goes without saying that a significant amount of energy will be required to adequately power an electric car of this class in the future.

Thousands of battery cells

This is achieved by interconnecting small battery cells - size 4 VDC/3200 mAh per cell - in parallel and in a row. 100 cells in a row are needed to attain an operating voltage of approximately 400 VDC. The endurance, range and performance of the overall package are then achieved by connecting many of these 400 V strings in parallel. In very powerful electric vehicles, several thousand cells are quickly assembled in this way.

Battery Balancing
Bearing in mind that thousands of such battery cells are fitted in an electric vehicle, the charging process is of great importance. The solution for this tricky task is referred to as "Battery Balancing". And this is how it works: The cells that absorb energy very quickly are slowed down a little. The weakest link in the chain sets the pace during the charging process. Each cell needs to be handled individually. This is the only way to use the maximum capacitance of a battery pack and to counteract any aging/weakening of individual cells.

Protect against a short circuit: Cell by cell

Of course each individual cell in the battery pack must be protected against over currents. This takes several thousand fuses per battery pack, depending on each individual one. There is no tolerance for errors here. So what demands are placed on this kind of fuse? Complete reliability is key. Such protection must work for at least 15 years without any hitches. Fuses must perform their function just as well in the coldest of winters as in the sweltering heat. Shock, vibration? Daily grind. Switching on, switching off, accelerating - cyclical strength is indispensable. The demands made on these fuses are enormous.

What about fuses in the context of AEC-Q200?

Specific tests and a set of specifically defined requirements for  fuses used in cars were not relevant throughout automotive development history. However, this has completely changed with the introduction of electronic control units and electric drives. Fuses will also be included as a topic in the next update of the Q200 standard.

SCHURTER focused on the high reliability requirements of the aerospace industry, which were developed in cooperation with ESA. This, together with the specifications for other passive components according to AEC-Q200, was also taken into account. Test procedures were developed for fuses, which meet the Q200 set of requirements, by working in close cooperation with key global players in the automotive industry. Fuses manufactured in this way may bear the unrestricted and internationally recognized Q200 "seal of approval".

Competent contact

SCHURTER now supplies a complete range of fuses for the automotive industry in accordance with AEC-Q200, supporting a wide variety of applications (battery management, air conditioning, close- coupled electronics for diesel and petrol engines, and much more). SCHURTER's close networking with international automotive organizations and the industry itself makes us highly competent to address all issues relating to the protection of electronics in the manufacturing of vehicles. 

Visit our website for more information

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Tuesday, 11 July 2017

The return of direct current

A lot of DC-operated devices are used in today's busy digital age – entertainment electronics, industrial IT, communication technology, electric vehicles and much more. At the other end of the energy supply chain, technologies quickly evolving to mimic the AC primary power chain with one that directly generates direct current, such as photovoltaics, fuel cells and wind farms. The use of direct current is therefore on the rise again: More and more electricity is supplied along the supply chain at least once in DC form in the areas of energy generation, transmission, storage and use.

Although conversions are necessary for stepping down voltage at times for technical reasons, in some cases these AC voltages and frequencies are probably still used because of predetermined infrastructure built upon years of standardization of AC power. However, these conversions always cause losses in power and thus energy waste, as well as generating unnecessary heat which can be avoided.

The DC approach

Direct current improves the quality of the power supply. It eliminates problems with unwanted harmonic waves and harmonic distortions. A phase compensation is also no
longer required. In addition to this, a synchronization is no longer required for coupling the various sources and networks. Even rectifiers and inverters are not required as the batteries are connected directly to the DC supply.

Quality of the supply

The DC power architecture contains significantly fewer components than that of alternating current. By eliminating various transformations and conversions there is already an increase in efficiency of 10 % from the supply to the server. In terms of investment costs for the electrical infrastructure, one should work off the basis of a reduction of around 15 %. Less space is also required for the electrical infrastructure. In fact, considerably less. 25 % should be expected. Fewer components are installed quicker. Fewer components are serviced faster and cause fewer errors. This makes them more reliable and therefore cheaper. 


Some data centers around the world already use DC technology. In China, Japan, the USA, Germany and also in Switzerland. However to date, there have been no binding standards to adhere to. The IEC (International Electrotechnical Commission) has set out to create the missing link with standardized plug and socket devices according to TS 62735. Efforts are currently being made to create solutions for DC plug connections on the previous AC standard IEC 60320. So far there are different approaches for DC connectors, but they have not been able to prevail due to the pending standards. That is why various providers are working together in the IEC standardization body in order to replace the proprietary approaches with an internationally recognized standard.

The conversion of the voltage supply must however be gradual. It is only in this way that all the devices will not need to be switched from an AC to a DC supply at once. Solutions are being sought that can feed the device with both an AC and a DC supply. The power supply units of the devices can process both supply voltages. However, it must also be ensured that all the safety-relevant precautions are taken.


Where there is light, there is also shadow. This also applies to the 400 VDC data center. The availability of DC components is still in its infancy. It needs a new approach. The use of a DC supply requires integral planning from the grid to the chip. And everything in between! Because there are still losses here - e.g. heat loss. This means: There needs to be cooling systems with a DC supply. Also needed are air conditioning systems, fire protection systems, access control systems as well as building control systems and much more. All of these components should be equipped to operate with direct current.


The supply of a data center using direct current has enormous potential. Not only does it offer the potential for saving energy, but also, to the same degree, savings on costs, space, resources and time. Furthermore, the supply of renewable energy sources offers the possibility of providing electricity directly for the data center as a direct current, without additional transformation or conversion processes. The quality of the DC-level power is better. This will result in the use of fewer components and, ultimately, greater reliability. Availability is the keyword in the digital age. Everywhere, at any time.

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Monday, 10 July 2017

Resistive Touchscreens vs Capacitive Touchscreens

Resistive vs capacitive touchscreens

Resistive Touchscreens

So what is a resistive touchscreen?

Well, firstly they are everywhere you go. You use them day to day without realising and examples of this include ATM machines, mobile phones and tablets. They are also found in medical and automation equipment. So how does it work?

In simple terms, Resistive Touchscreens rely on resistance. This means that the pressure you apply causes the screen to respond to that pressure. Resistive touchscreens are built from two layers of material with a gap between them. These layers both have a coating on one side. When you push on the outer screen the two layers of coating press against each other and a voltage is passed through, meaning it is then processed as a touch in that position.  Since this process is based on pressure, it can be used by any object including gloved fingers, a stylus or even a fingernail.

Today Resistive technology is a mature and well-known technology. Resistive technology has been available within the SCHURTER group for nearly 20 years. SCHURTER has built upon extensive knowledge of resistive technology, the manufacturing of the products and the materials used. As a result of this SCHURTER can help you to fulfil your needs.

Resistive vs capacitive touchscreen

Capacitive Touchscreens

What is capacitive technology?

Capacitive touchscreens are found across both the industrial and consumer markets, an example of the consumer market would be the iPhone. Capacitive touchscreens rely on the touch of a conductive object which can be as simple as just your finger. Capacitive touchscreens are highly responsive. This is because they do not depend on pressure to register a touch so that even the slightest contact will activate the screen. A capacitive screen is usually made of one insulating layer, such as glass, which is coated with a transparent conductive material on the inside.

Capacitive touchscreens can use glass as the front panel, this makes them hard-wearing, resistant to scratches and easy to clean. The screens are also more sensitive and precise with a much sharper display and a better overall look due to there being only one layer instead of several. Capacitive touchscreens can also implement multi-touch gestures, allowing you zoom in and drag.

The only downside to using a capacitive touchscreen is that you need to touch with an item that has a capacitive charge. So for example, if you were to use a pair of gloves then the touchscreen would not respond.

We at SCHURTER offer capacitive touchscreen solutions for business across many industries ranging from Building Equipment to Agriculture and Forestry.

For more information both on resistive and capacitive touch screens check out the SCHURTER website.