perfect thermal management

Hysteresis… isn’t that a Def Leppard Song?

Although you may not have grown up in the ’80s, you’ve likely heard of the 80’s rock band, Def Leppard. One of my favorite hit singles from the same-titled album is “Hysteria.” Take a trip down memory lane and give it a listen (or, if you’re * ahem * much younger, just give it a try anyway, and don’t rub it in on us older folks!)

Hysteresis… isn’t that a Def Leppard Song?

This isn’t about big hair bands and one-armed (but still awesome) drummers. It’s about hysteresis. An understanding of application-specific hysteresis is one of the design features of the STEGO Compact Thumbwheel Thermostat.

To get a better understanding of this feature, let’s start with a definition. The dictionary defines hysteresis as retardation of an effect when the forces acting upon a body are changed.

Hmm… that is still a bit confusing.

Let’s look at our homes since the thermostat in your house’s HVAC offers a good example.

Say you like your home temperature at 72 degrees. If the A/C tries to keep that nice, even 72 degrees while it’s 98 degrees outside, the system will struggle to keep up and will constantly turn on and off.

With a hysteresis thermostat, you can set your temperature to 72 degrees and be better able to maintain it. Why? The temperature will go up to 74 degrees before cooling it down to 71 degrees, allowing the HVAC system to relax. This saves on wear and tear and fosters energy efficiency.

Thus, you can stay cool while you air guitar to your satellite radio’s “Big 80’s on 8”.

Now – back to electronics enclosure design, where we have a similar goal. You need to maintain a temperature setting, but a very tight temperature window could overtax your system, potentially leading to poor energy efficiency. At STEGO, we know thermal management, and we’ve built in ‘smart hysteresis’ into our thermostat design. Sometimes a picture is a better way to visualize a concept, so see this chart below for an example:

The image above depicts the expected closed/open contact state for a 20℃ setpoint across an operating temperature range. Note the expected results given the hysteresis 7K with a tolerance of 4K. The tolerance can be confusing to interpret, so feel free to give us a call to help further explain.

There are other key features of this product, including anti-frost assurance and high switching capacity. For more information, see the full datasheet here (

The compact thumbwheel thermostat is but one example of the many tools we offer at STEGO. The continual battle against heat and humidity to keep your control enclosure running smoothly is annoying and costly. Our German-engineered thermal management solutions will do that fighting for you, so you can spend your time designing instead of monitoring and fixing (doing damage control).

Designing complex electronics that perform perfectly outdoors is, well, complex. At STEGO, we believe that protecting those complex projects from extreme climates should be the simplest part of your design. That’s why we use German engineering to create the highest quality thermal management components to protect your designs from anything Mother Nature throws at it. We’ve been pioneering Thermal Management for over 40 years now. With STEGO parts installed, you can rest easy that your complex design is reliably protected for the long haul.