Micrometals

Their site
http://www.micrometals.com/
doesn't seem to be responding.

Does anyone else have this problem ?

Graham

 

Yes.

 

Opened straight away for me.

 

Fine for me.

 

I notice that your posting was, apparently, at about 3AM Pacific time
(Micrometals time zone). It may well have been that their site was
down for maintenance at that time. Works fine for me now.

Cheers,
Tom

 

Works for me.

 

Looks OK now. Their powdered iron stuff sucks for power apps (tends to
burn the paint off the cores) but I think they now have a KoolMu
equivalent that's pretty good.

John

 

Me, too.

It must have been a temporary glitch, or a scriptkiddie/browser
incompatibility.

Cheers!
Rich

 

Thanks, it's up again now.

Graham

 

John Larkin wrote:

"burn the paint off"? Man, what are doing with them? ;-) Doesn't that
cause permanant damage to the core? I was under the impression that heating
a core too much could/would lead to permanant changes in the Al value.
Maybe this only applies to ferrite?

 

You don't use output inductors in your buck derived converters. Micrometals
is just saving bandwidth.

DNA

 

If you ignore the specific power loss graphs then all powdered iron sucks
for power apps.

DNA

 

It's not buck derived.

Graham

 

So.....

Since you didn't use an output inductor in your buck derived converter it
blew up so you decided to use a different topology and this one is having
similar blowing up problems so you are going to use an output inductor with
it.....

Excellent!

DNA

 

It was a kilowatt polyphase buck switcher, essentially three buck
switchers in parallel with timings offset 120 degrees. The powdered
iron toroids fried, even with lots of air flow. I went to permalloy
powder, expensive but efficient. The CoolMu types are almost as good
as permalloy for things like this, but a lot cheaper.

I "invented" the 3-phase switcher in 1985, but I'm fairly sure
somebody beat me to it.

John

 

Any expiry of mosfets had zilch to do with the output circuit. If you recall
there was an 'undocumented feature' of the controller chip.

Tell me something.....

Do inverters use output inductors

Graham

 

My first experience of using Micrometals powdered iron toroids was in that power
supply I was working on a couple of years back. They aren't the easiest thing to
get hold of so I got some from RS components just to try.

They smoked very nicely. They were only -26 material though. When I got some in
-2 it was a very different story.

Graham

 

Go on then....

DNA

 

Go on....... what ?

Graham