Copyright: voestalpine Weichensysteme GmbH

Railway switch heater pre-installation test

Yesterday we successfully passed the pre-installation test of our railway switch heaters at the Austrian Federal Railway infrastructure unit (ÖBB-Infrastruktur AG). At 08:30 pm we showed up in the Vienna headquarters on Praterstern, met the responsible engineer and went to the testing workshop located nearby.

The workbench was too short, and so we had to to place the 2 meter long heater on the floor. In order to avoid heat sinks distorting the results, ÖBB staff put it on a bubble wrap foil. Wrapping paper was applied to the shiny stainless steel surface which otherwise would not allow for reliable measurements with the thermographic camera brought along.

Test setupThermographic image of switch heater







As a first step, ÖBB measured the isolation between ground and power cables which was 600 MOhm which was the maximum which the device could measure. Then they powered the heater with 225V DC and measured voltage, current, and surface temperature over a period of 25 minutes according to their test procedures. The result of the measurements can be seen below.

Value ChartValue Table













At room temperature, the heater hat a power consumption of 350W which is exactly the nominal heating power of the device. Despite the fact that the surface is comprised of a 1 mm steel sheet, the heatup curve was very steep and after 2 minutes 50°C were reached. The target temperature range of 60-65°C was reached after 5 minutes already. In order to keep the device as robust and simple as possible and avoid the use of control units, we are using ATT Powerfilms based our E-type conductive ink with an extreme PTC curve. Above 60°C the resistance rises so sharply that the heatup stops without the use of electronics or bimetallic switches. The heater temperature stabilised exactly in the specified range and the power consumption at appr. 110W, only a third of the nominal power. As a final step, the isolation was measured again, which gave a result of 308 MOhm which is far above the minimum according to ÖBB requirements.

ÖBB seemed very impressed by our switch heaters, both by their performance (and in particular the intrinsic self-regulating function) and the quality of manufacturing. The successful pre-installation test qualified our product for use in switching systems, and as a next step they will be installed in switches along a much
-used railway line for winter testing. We will keep you posted about the results …

Crossing the NordbahnstraßeReturning to ÖBB headquarter


Heating system for modern cashier desks

Currently we have finished our latest project: a cashier desk heating system based on ATT Powerfilm technology. The special heating polymer we are using in this case has the capability of perfect self regulation without the need of introducing electronics. It will stabilize itself at 60°C @ 230V, which will end in a very comfortable radiation effect and a noticeable improvement of the thermal comfort of people working at cashier desks. If everything runs fine, the series production of this system will start next year after the test phase during the next months.Desk_Heating_03 Desk_Heating_02 Desk_Heating_01

Copyright: voestalpine Weichensysteme GmbH

Heating element for railway switches

Railway_01 Railway_02The winter can be very cold and unfriendly. In order to prevent railway switches from malfunction, ATT developed and produced the first prototypes of heating elements for railway switches based on ATT PowerFilm technology. They will be tested during the winter 2015/16 under real life conditions. We are looking forward to getting the results!

Movie Screenshot

Real-time footage of heatup behavior

Movie Screenshot
In this short clip the heat-up results of a very “quick and dirty” prototype setup of two different objects can be seen. The base materials were directly coated with our thermoelectric polymer, whereby the voltage was set to 220V. The heating power in this setup was about 30 kW/m². With this setup we were able to heat up the 6mm thick concrete to 100°C within 40 seconds. After reaching this temperature, the concrete stayed warm for more than 30 minutes. Just amazing.

Please follow the link to watch the video

Stable material at high temperature

High temperature tests

This week, a couple of severe misuse tests have been performed. Very interesting were the high temperature tests of  a standard PowerFilm element. Even at temperatures between 200°C and 220°C the element stayed 100% stable and was not damaged. To prevent the ground – on which the element was placed on –  from being damaged, we used some insulation material to place the heating surface on. Because of the thinness of the element it is not always 100% connected to the ground and therefore pillows of air are locally trapped between the PowerFilm and the ground. As air is a very good insulator, the areas of the heating element under which air is located, get warmer than areas which are perfectly fitted to the ground. At the demonstrated heating performance this effect leads to locally different temperatures, which can be seen in the picture below.

 Stable material at high temperature

the burn

Fire & Ice

Last week we had the annual Mountain Film Festival in Graz, a must for all who enjoy mountains and nature. We went there on an evening with an appearance of Jamling Tenzing Norgay, son of Tenzing Norgay, first human on the Everest together with Edmund Hillary. He gave us a lot of insight into life in Himalaya and in particular the Sherpas (which means “Eastern People” as I now know). Amazing!

At the beginning, however, they showed a video which inspired me a lot … because it combines several of my passions, including fire, show, nature, and of course skiing! Watch this, it isn’t long but will surely impress you: The Burn. The season is approaching … Schi heil!!!

the burn


Morning frost

The early morning can be frosty on the east side of the Alps these days … and very beautiful, too. At least for someone who can walk the dog at sunrise and then return into a warm home and have breakfast with hot coffee.

It is quite a different story for my neighbour, who has no time for walking the dog and a lot of jobs to do with his tractor. Well, well … with our Powerfilm he would have a cozy cabin in no time and no hassle with window de-icing. A coffee machine should fit in as well. We should really consider developing a vehicle coffee-maker with a sensor measuring driver mood and automatically proposing a hot beverage at the right moment! One more idea for our collection …