Is this too hot

[SoundMods]

They claim that the case is the heat sink.
what do you think?

My view? Wishful thinking on their part.

Most capacitors and integrated circuits are only rated to 85-degrees C (185-degrees F) on a good day. If the case is hot enough to cause extreme discomfort when laying your hand on it, then that could very well be close to 130-degrees F. So you have to ask -- how hot is the core temperature -- inside the case? With the case being that hot I expect it is not getting the job done. It sounds like it definitely needs added heat sinks to control device heat.

But then -- extruded aluminum heat sinks are costly and to keep within a price point they hope the device survives. Yet they have no control over end-user placement and that is the error in their thinking.

Look at Dayton Plate amps as an example. Their product line once relied on the plate to serve as a heat sink -- and reportedly they had the failures to prove that it was mistake. Their current stuff all have external heat sinks.

[ratbagp]

Does the device have ventilation holes?

ray

[Pelliott321]

no ventilation holes
This unit has been out there for over a year and no failures according to the manufacturer.
They have similar form factor units that have bee around longer

[DaveR]

While they may not have had any failures yet, it's a poor design practice to make a product that runs that hot.

[Pelliott321]

my original question was "what is too hot". Steve asked it again.
I measured a max of 119 degrees F
Is this too hot?

[SoundMods]

my original question was "what is too hot". Steve asked it again.
I measured a max of 119 degrees F
Is this too hot?

It comes down to what is going on inside the case. If there were efficient heat transfer with plenty of metal [heat sink(s)] the case would not get that hot. Assuming typical room ambient, the area and mass of the small form factor, and the lack of an external heat sink or even vent holes, it doesn't surprise me that it gets almost too hot to touch. Again, that brings to question -- what's going on inside?

[dberning]

119 degrees F should not be a concern. I would worry if it was 119 degrees C. It is not uncommon to run 3-terminal regulators 70-85 C. Capacitors tend to suffer the most when in a hot environment, but if they are no hotter than 119 F they should be OK. As far as SS devices are concerned, much improvement has been done over the years with matching coefficients of expansions between plastics and silicon chips, and wire bonds popping off is no longer much of an issue. This was the most common failure years back. Of course thermal runaway due to safe-operating-area violation is another issue. That can occur at much higher localized spots on a chip when silicon reaches its intrinsic temperature, around 250 C. At this temperature a silicon transistor can no longer be switched.

Interestingly, I was just reading an article on planning for a mission to Venus with electronics built to operate where the average surface temperature is 464 C. The semiconductor silicon carbide can reportedly still switch at 1000 C. The passive components still need work.

So... it all depends on how you do it.

[Pelliott321]

The manufacturer claims the typical op temp of the top of the case is 119-126F and components are running at or better than half their rated maximum.
The unit has three year warranty so I am going to put it out of my mind and move on.
Just wanted to see what you guys felt about this.
Thanks

[SoundMods]

The manufacturer claims the typical op temp of the top of the case is 119-126F and components are running at or better than half their rated maximum.
The unit has three year warranty so I am going to put it out of my mind and move on.
Just wanted to see what you guys felt about this.
Thanks

Sure -- three-year warranty -- if they are still in business to support the warranty.

[Riley Casey]

Suspend the device at least it own largest dimension distance above and away from any large surface it may be sitting on and allow the chimney effect to draw cooler air from below past the case. Suspending it in a tube ( an actual chimney ) will make the effect slightly more efficient but add a lot more aggravation. It won't cool it down as much as a fan but it will certainly be quieter.