Help!! Need an enclosure FAST...

isn't the rule 1 watt per square inch still valid? 14 square inches of case should suffice.

Cheers

nd Waldorf. I hope you find something. I've not seen any product this int eresting for heat dissipation. Why is it you can't buy it from Takachi? .. .

ational holiday. So, we won't know until tomorrow (maybe?) whether they ev en have these in stock. And the clock is still ticking...., and they still have to get here.

ything that looks quite as nice as these Takachi boxes, short of rolling so mething custom that we just don't have time for. (And if you think that's bad, I haven't mentioned the stress getting the box internals done!)

r upcoming trade shows. Period. (Note: Will never happen.)

You've avoided telling us what you're doing with it, so I don't know whethe r to mention other options or not.

NT

and Waldorf. I hope you find something. I've not seen any product this i nteresting for heat dissipation. Why is it you can't buy it from Takachi? ...

national holiday. So, we won't know until tomorrow (maybe?) whether they even have these in stock. And the clock is still ticking...., and they sti ll have to get here.

anything that looks quite as nice as these Takachi boxes, short of rolling something custom that we just don't have time for. (And if you think that' s bad, I haven't mentioned the stress getting the box internals done!)

for upcoming trade shows. Period. (Note: Will never happen.)

her to mention other options or not.

Not the most helpful response ever posted.

--
Bill Sloman, Sydney

I'm using an AWP-series enclosure in a project right now. Their products range from decent to great, but those serrated heat sink fins are SHARP. If you ever get your hands on one, consider that a word to the wise. I evaluated several of their enclosures including that one, and almost had to get stitches after grabbing the heat sinks on the side of an HY chassis at the wrong angle.

The fins might or might not be helpful, but the detailed serrations on them are totally useless due to boundary-layer effects. They are just too small and too densely organized to do anything other than slice fingers open. I'll give them credit for publishing degs/W numbers in their brochures, though.

Another helpful tip when dealing with Takachi is that there is *always* some kind of vacation, holiday, or other extracurricular business that makes communication challenging. Plan ahead and give them plenty of time, emergency orders aren't their thing.

It's crazy how few domestic manufacturers sell quality electronic enclosures that you wouldn't be embarrassed to use in a commercial product. Lots of room for competition in that business IMO.

-- john, KE5FX

Nor yours.

Our thermal specialist has a rule that dimensions below 6mm wont do any good, since the air wont "flow" in such small dimensions, just stay there

Cheers

Klaus

:

r and Waldorf. I hope you find something. I've not seen any product this interesting for heat dissipation. Why is it you can't buy it from Takachi? ...

of national holiday. So, we won't know until tomorrow (maybe?) whether the y even have these in stock. And the clock is still ticking...., and they s till have to get here.

d anything that looks quite as nice as these Takachi boxes, short of rollin g something custom that we just don't have time for. (And if you think tha t's bad, I haven't mentioned the stress getting the box internals done!)

) for upcoming trade shows. Period. (Note: Will never happen.)

hether to mention other options or not.

I don't know. NT makes a habit of posting responses that aren't worth readi ng - he's pretty much down there with skybuckflying for posting useful cont ent - so a comment to that effect may be helpful at a higher level.

--
Bill Sloman, Sydney

A request for more relevant info is not helpful? Must be Planet Slowman.

NT

whether to mention other options or not.

NT neglects to mention that he never does anything with the extra informati on he thinks he's asking for - he's a black hole when it comes to informati on.

He has been known to express demented opinions, so his idea of "relevant" i sn't great either. Precisely what made his very unspecific request for extr a information "relevant" escapes me, and I can be confident that I won't be any better informed if he bothers to respond.

--
Bill Sloman, Sydney

onsdag den 8. maj 2019 kl. 05.32.15 UTC+2 skrev John Larkin:

and as I recently found out the thermal conductivity of the anodizing is absolutely horrible

Why would that matter? Anodizing is pretty thin. Nothing is a good thermal insulator if it is thin enough. What type of anodizing are you talking abougt? How bad is this supposed to be? I'm not familiar with the "horrible" spec.

--

  Rick C. 

  + Get a 1,000 miles of free Supercharging 
  + Tesla referral code - https://ts.la/richard11209

It turns out that anodizing makes a massive difference. Hard to appreciate just how much until you play with a thermal camera. Emissivity of an anodized surface is in the 0.9 range. The same enclosure with a conductive alodine treatment will look essentially identical visually, but its infrared emissivity will be a small fraction of that, maybe 0.2 or so.

The net effect is that an anodized enclosure will feel substantially cooler to the touch but will appear quite a bit hotter on an IR camera. Thickness of the surface treatment has nothing to do with it, another somewhat unintuitive fact. It's all about the free electrons at the surface as I understand it. There's some correlation between thermal conductivity and electrical conductivity for similar reasons.

-- john, KE5FX

x

rea

installed.

s absolutely horrible

mal insulator if it is thin enough. What type of anodizing are you talking abougt? How bad is this supposed to be? I'm not familiar with the "horri ble" spec.

the usually grey anodizing on extruded alu enclosures with heat sink fins

I didn't do the measurements but milling off the anodizing where a transist or was bolted to the inside made a big difference

Two points... One, you are talking about radiation while Lasse is talking about conduction of the anodizing. Two, the emissivity effect you are talking about indicates the anodized enclosure is actually better for getting rid of the heat.

Or maybe I missed your point?

--

  Rick C. 

  -- Get a 1,000 miles of free Supercharging 
  -- Tesla referral code - https://ts.la/richard11209

On Saturday, May 11, 2019 at 5:30:22 PM UTC-4, Lasse Langwadt Christensen w rote:

box

area

rd installed.

t

x.

is absolutely horrible

ermal insulator if it is thin enough. What type of anodizing are you talki ng abougt? How bad is this supposed to be? I'm not familiar with the "hor rible" spec.

stor was bolted to the inside made a big difference

I don't know what to tell you. Perhaps there was some other effect like th e anodized surface not being very flat? Anodized layers are less than 1 mi l up to 5 mils depending on type. It's pretty hard to get much insulating properties in 5 mils of thickness. How many watts? How large of a surface ? What was the observed temperature change?

--

  Rick C. 

  -+ Get a 1,000 miles of free Supercharging 
  -+ Tesla referral code - https://ts.la/richard11209

o box

ce area

oard installed.

hot

box.

he

ng is absolutely horrible

thermal insulator if it is thin enough. What type of anodizing are you tal king abougt? How bad is this supposed to be? I'm not familiar with the "h orrible" spec.

ns

sistor was bolted to the inside made a big difference

the anodized surface not being very flat? Anodized layers are less than 1 mil up to 5 mils depending on type. It's pretty hard to get much insulatin g properties in 5 mils of thickness. How many watts? How large of a surfa ce? What was the observed temperature change?

I didn't do the measurements, the surface is ~10mmx30mm, maybe 50watt

On Saturday, May 11, 2019 at 6:22:32 PM UTC-4, Lasse Langwadt Christensen w rote:

zing is absolutely horrible

d thermal insulator if it is thin enough. What type of anodizing are you t alking abougt? How bad is this supposed to be? I'm not familiar with the "horrible" spec.

fins

ansistor was bolted to the inside made a big difference

e the anodized surface not being very flat? Anodized layers are less than

1 mil up to 5 mils depending on type. It's pretty hard to get much insulat ing properties in 5 mils of thickness. How many watts? How large of a sur face? What was the observed temperature change? 3 cm^2 at 5 mil thickness (hard anodizing) would be about 70 W/K. That wo uld seem to be less than one degree Kelvin from removing the anodized layer .

--

  Rick C. 

  +- Get a 1,000 miles of free Supercharging 
  +- Tesla referral code - https://ts.la/richard11209

dizing is absolutely horrible

ood thermal insulator if it is thin enough. What type of anodizing are you talking abougt? How bad is this supposed to be? I'm not familiar with th e "horrible" spec.

k fins

transistor was bolted to the inside made a big difference

ike the anodized surface not being very flat? Anodized layers are less tha n 1 mil up to 5 mils depending on type. It's pretty hard to get much insul ating properties in 5 mils of thickness. How many watts? How large of a s urface? What was the observed temperature change?

3 cm^2 at 5 mil thickness (hard anodizing) would be about 70 W/K. That would seem to be less than one degree Kelvin from removing the anodized lay er.

?1 and thought no problem, but then I looked up numbers for anodizi ng and found multiple papers where they had measured it as more like 1 W?

Right, it doesn't conduct the heat, so much as it sheds it. These effects are related to some extent.

-- john, KE5FX