Pt-Heater max Watt Density

Electromechanical Fans, Thermal Management
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Looking at the product, HST.P11R0.1010.63A.2L.020, I am unable to see the Watt density at 12v. I was wondering if this information is available. Also curious as to the ability to use this product past 12v.

Thanks in advance

2

Hello,

welcome to the TechForum!

I was not able to locate this information on the datasheet or the mfgr’s website. I will email the Product Manager and see if the company can directly answer this question. This may take 1-2 days to hear back but we will post it as soon as we can.

https://www.ist-ag.com/en/products/micro-heater-200degc-optimized-12-v-power-supply

I also have a link to the mfgr. website but there is not much more info just a few more details.

Thank you
Ryan

3

The datasheet indicates the device is based on a PTC thermistor material:
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This would mean that the steady-state power density is not definable without specifying a complete set of operating conditions, since the device resistance will vary with temperature, which will in turn be affected by the rate of heat transfer from the device itself.

That said, the nominal resistance is stated to be 14Ω with dimensions of 10x10mm, making the power density with a 12V supply roughly 10W/cm2 under whatever conditions result in the stated resistance figure being applicable.

Operation at higher supply voltages will naturally result in higher power densities. While the R vs. T curves for the device are (disappointingly) not published, the self-regulating behavior of a PTC device could be expected to make modest excursions past the 12V mark tolerable. The limits of such use would be difficult to determine without the manufacturer’s provision of more comprehensive data however.

1 Like
4

Hello, we just got some additional information from the manufacturer, Rick was pretty much on the money, though the manufacturer varies slightly in some of the specs they referenced in their answer:

  • Since heating trace is made of Pt, its resistance is temperature-dependent. Same goes for watt density at specific voltage, too. If we assume room temperature, this heater has around 12 Ω resistance, resulting in a 12 W/cm2 power density when applying this voltage. This will drop down with temperature as (scales roughly as 1/T).

  • Higher voltages in themselves are not immediately problematic. However, overheating must be avoided. If the thermal environment of the heater is such that enough heat is dissipated, voltage could be increased minimally. There are more variables, so the main point is that overheating is critical.