The perfect wave

Electromagnetic waves – does that ring a bell? Perhaps memories of physics lessons from school days long past come to mind? If not, we will be happy to jog your memory. Welcome to our laboratory on electromagnetic compatibility!

A bit like a recording studio: Robert Plachetka (right) shows Kobold advisor Marcel Palte the laboratory on electromagnetic compatibility (EMC).

Whether in cell phones, coffee machines or children’s game consoles – electromagnetic waves are indispensable for the smooth functioning of electronic devices. Of course, this also applies to our premium household appliances Thermomix® and Kobold. That is why we at Vorwerk operate our own laboratory on electromagnetic compatibility (EMC). It is an integral part of our development process. Laboratory manager Robert Plachetka and his colleague Sven Klein explain to our Kobold advisor and laboratory visitor Marcel Palte what happens here and how customers benefit from it.

“This looks like a recording studio!” — Marcel Palte

You don’t have to be a former professional musician like Palte to make this observation. The impressive interior paneling of our EMC room reminds many visitors of a recording studio. This is due to the foam absorber pyramids that dampen the electromagnetic echo. The walls are also covered throughout with ten by ten centimeter tiles made of ferromagnetic material that also shield waves. “There are 23,000 tiles in total, which corresponds to a weight of 6 tons. We have a whole elephant hanging on the wall, so to speak!” says Klein and smiles. The equipment is otherwise quite basic: a table for test specimens and two antennas that conceal high-tech measurement technology.

“You can imagine electromagnetic waves like the waves of an ocean: they also vary in terms of length and strength.” — Robert Plachetka

All devices that are powered by electricity from a socket or battery power emit electromagnetic radiation. There are many different types: radio waves, microwaves, light, etc. “You occasionally hear about cell phone radiation – but a vacuum cleaner? To be honest, I didn’t realize that every electrical appliance emits waves,” says Kobold consultant Palte. Klein: “Basically, our appliances are radio systems – except that you can also vacuum and cook with them.” To keep with the image of laboratory manager Plachetka: In a normal apartment, all these waves ripple wildly, just like in an ocean. And of course they can influence each other. In a real ocean, this might not be a problem. In our ocean household, however, this interference can lead to so-called noise and disrupt the functionality of the appliances. “This topic is very important in my demonstrations. If someone is interested in a high-priced product like the Kobold VK7, for example, they want to be sure that it will work perfectly for a long time,” says Palte.

2000

tests are performed annually in Vorwerk’s 4 EMC test rooms.

23000

tiles cover the walls of the EMC room and shield electromagnetic waves.

“Our findings are important for the further development of a new product and for its entire life cycle.” — Robert Plachetka

The laboratory team performs around ten tests a day on average. Some take minutes, others up to an hour. “We test how resistant our devices are to external influences and what they themselves emit. This involves waves that are transmitted through the air and those that come via electrical cables,” expert Plachetka explains. Finished products as well as prototypes, preliminary stages and individual components are tested. Klein: “We work alongside development and series production and also repeatedly test products and parts that are already on the market.”

Robert Plachetka is an engineer and has always worked in electronics development – for Vorwerk for 20 years. Back then, the EMC laboratory was still very small, but it has grown just as rapidly in line with the rapid technical progress. The laboratory manager and his four employees now perform around 2,000 tests a year.

Marcel Palte is a Kobold advisor and enjoys having direct contact with customers. The former professional musician always has several vacuum cleaner models in his car during his demonstrations so that he can meet everyone’s needs. What particularly impressed him in the EMC lab? “It’s amazing how many tests are performed here. I would never have imagined that.”

Robert
Plachetka

Marcel
Palte

“It’s insane how many tests are performed here. As soon as a new component is installed in a model, the tests start all over again.” — Marcel Palte

That’s why the component crisis during the coronavirus pandemic was the toughest nut to crack to date for Plachetka and his four employees. “When the supply chains were interrupted, we had to procure and validate a number of new components,” the electrical engineer recalls. “The testing effort was enormous. Having our own EMC laboratory was very helpful. While others were queuing up at TÜV, we were able to do everything ourselves.” Even without global crises, the laboratory offers many advantages because it makes development very efficient. If you have your devices tested by TÜV or VDE before they receive market approval, they are already built. If any problems are identified, you have to intervene heavily in the device. “Having your own laboratory is a luxury. But in terms of the efficiency and quality of our developments, it’s worth it,” says Plachetka. The topic of components and upgrading models is also important for sales: “Many customers don’t want to have to buy a complete new package right away, they want to upgrade their Kobold model,” says advisor Palte. “The fact that product series are compatible, that we use exchangeable batteries and so on are clear selling points.”

“There are many laws that we have to follow, along with our own internal standards. And they are much stricter.” — Robert Plachetka

EMC tests are generally not just about the interaction of devices. They also involve identifying and preventing influences on people. “Our devices cover the lower range of radio and microwaves and emit power that is far removed from any potential effect on people,” says laboratory employee Klein. However, it is not just about German standards and laws; after all, Vorwerk sells Thermomix® and Kobold worldwide. “Germany, the United States and Japan have different mains voltages, for example, and that alone can be a reason for different limit values. The country variants are a big multiplier for us and we have to take them into account when testing all components and products,” Plachetka explains.

Well shielded: Laboratory manager Robert Plachetka (right) with his colleagues Fabian Radau, Luca Kohnen and Sven Klein in the EMC room.

“Our work is strongly linked to trends. We always have to have our finger on the pulse.” — Sven Klein

Advancing digitalization, aspects such as connectivity, the Internet of Things and mobility are influencing testing in the laboratory. “Even if our devices don’t have or need some functions, we have to consider everything possible. We have to plan ahead to see which devices customers use at home and what interactions could arise,” explains Klein. Battery technology, for example, is a strong trend, as is mobile Internet. “Finally, TÜV, VDE and other external laboratories also test again,” says Plachetka. “We are relaxed about these tests because we test well ourselves throughout the entire process. We have actually never failed.”

“Inspiration and creativity are important topics to us. We have already surprised many an engineer with our ideas.” — Robert Plachetka

Quality figures are very important to Vorwerk. If problems arise with a test specimen, the laboratory technicians have to solve them creatively and resourcefully with the development team. “You don’t learn EMC at the university,” laboratory manager Plachetka, who has always worked in electronics development, explains. EMC, a side effect of the rapid technical progress of our time, is still quite young. “When I started working at Vorwerk 20 years ago, there was only a very small laboratory, where free-field measurements were taken in a meadow in Rauental.” Klein, who started out as an industrial mechanic 27 years ago, also remembers these times: “Training is very important at Vorwerk, and I was able to make intensive use of this.” After holding several positions, he eventually joined the Research & Development department, where he also helped to set up the EMC laboratory. “To be honest: I enjoy it here every single day.”

Take part in our quiz!

The EMC laboratory opens its doors for guided tours from time to time. According to lab employee Sven Klein, one thing in particular catches the eye of guests – what is it?

You can get the answer by clicking on the white tiles.

“It is the purest digital detox.”

Sven Klein: “Waves are shielded completely here. This means visitors are in an offline world with us. It is the purest digital detox. It feels very strange for many people.”