"Heat Sink Putty" ?
 

Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.
--
PeteCresswell

"Heat Sink Putty" ?
 

I've never heard of putty. Silicone grease is common, of course.

"Heat Sink Putty" ?
 

"(PeteCresswell)" wrote:

Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.

Aluminium powder mixed with epoxy might work.

Graham

"Heat Sink Putty" ?
 

"(PeteCresswell)" wrote in message
...
Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.

**Do you need heat sinking? 4 Watts is not much power. You could use a 6 Amp
bridge, which can dissipate quite a bit of power, before requiring any heat
sink. If you do need it, then use silicon glue (the stuff used for
guttering, kitchens, bathrooms, etc). It remains flexible and will transfer
reasonable heat to the frame. I seriously doubt that you need it though.

Trevor Wilson

"Heat Sink Putty" ?
 

In article ,
Eeyore wrote:

"(PeteCresswell)" wrote:

Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.

Aluminium powder mixed with epoxy might work.

Graham

Don't they make thermally conductive epoxy? OP might not want anything
electrically conductive.

"Heat Sink Putty" ?
 

In article , "(PeteCresswell)" wrote:
Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.

Thermal epoxy is better than regular epoxy but the conductivity
is very poor compared to copper, and copper is poor compared to diamond.
Might try the suggestion of adding metal filings to regular epoxy putty.
Thermal epoxy is not really putty.

greg

"Heat Sink Putty" ?
 

In article , (GregS) wrote:
In article , "(PeteCresswell)"
wrote:
Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.

Thermal epoxy is better than regular epoxy but the conductivity
is very poor compared to copper, and copper is poor compared to diamond.
Might try the suggestion of adding metal filings to regular epoxy putty.
Thermal epoxy is not really putty.


The thermal epoxy I am currently using on a project is a lot thicker than
regular epoxy. Its Omega Bond 101.

greg

"Heat Sink Putty" ?
 

On Sun, 02 Mar 2008 18:36:38 -0800, Smitty Two
wrote:

In article ,
Eeyore wrote:

"(PeteCresswell)" wrote:

Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.

Aluminium powder mixed with epoxy might work.

Graham

Don't they make thermally conductive epoxy? OP might not want anything
electrically conductive.

Then use zinc oxide with epoxy, that should not be conductive... But
regardless, nothing will work very well, IMHO...

"Heat Sink Putty" ?
 

In article , PeterD wrote:
On Sun, 02 Mar 2008 18:36:38 -0800, Smitty Two
wrote:

In article ,
Eeyore wrote:

"(PeteCresswell)" wrote:

Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.

Aluminium powder mixed with epoxy might work.

Graham

Don't they make thermally conductive epoxy? OP might not want anything
electrically conductive.

Then use zinc oxide with epoxy, that should not be conductive... But
regardless, nothing will work very well, IMHO...

Seems like there are atachments to the frame for accesories, and if they
are aluminum, it will make a great way to do it. Curved surface aluminum
block.

greg

"Heat Sink Putty" ?
 

"Heat Sink Putty" ?
 

(GregS) wrote in
:

In article ,
"(PeteCresswell)" wrote:
Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.

Thermal epoxy is better than regular epoxy but the conductivity
is very poor compared to copper, and copper is poor compared to
diamond. Might try the suggestion of adding metal filings to regular
epoxy putty. Thermal epoxy is not really putty.

greg

there's a silver-filled thermal epoxy,Arctic Silver.

http://www.arcticsilver.com/instructions.htm

http://www.newegg.com/Product/Produc...82E16835100005

--
Jim Yanik
jyanik
at
kua.net

"Heat Sink Putty" ?
 

On Mar 2, 3:46*pm, "(PeteCresswell)" wrote:


I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink. * *

If there's a brazed boss in some convenient spot, you can screw a
block of aluminum to that (or even a 1" square plate). The rectifier
won't need conduction cooling at these power levels, so it's just
the (three terminal TO-220?) regulator or pass transistor that gets
warm.

Generator mount bracket or headlamp bracket are good candidates.
If they get warm, it sinks to the frame quick enough.

"Heat Sink Putty" ?
 

On Mar 2, 6:46 pm, "(PeteCresswell)" wrote:
Any such thing?

Loctite makes a number of thermally conductive paste adhesives,
and even a thermally conductive RTV. I've used 383 to fill small
holes, its consistency is similar to acrylic latex caulk.
http://www.loctite.com/int_henkel/lo..._ThermMgmt.pdf

TM

"Heat Sink Putty" ?
 

Smitty Two wrote:

Eeyore wrote:
"(PeteCresswell)" wrote:

Any such thing?

I'll have a little bridge rectifier and voltage regulator serving
a bicycle hub alternator (6v 4w) and want to use the bike frame
as the heat sink.

My thought was that, if there's such a thing as heat-conductive
putty, I'd just embed the two components in some of it and stick
it to a frame tube.

Aluminium powder mixed with epoxy might work.

Don't they make thermally conductive epoxy? OP might not want anything
electrically conductive.

Bridge tectifiers usually have isolated cases anyway.

Trevor's idea is good though. Use a larger bridge than actually needed
(they're not expensive) and it'll happilly dissipate the heat without
additional cooling.

Graham

"Heat Sink Putty" ?
 

Jim Yanik wrote:

Or use a switcher-type regulator for lower heat dissipation.

That's a particularly good idea.

Graham

"Heat Sink Putty" ?
 

Per Trevor Wilson:
**Do you need heat sinking? 4 Watts is not much power. You could use a 6 Amp
bridge, which can dissipate quite a bit of power, before requiring any heat
sink.

I just checked the specs on the one I ordered. 25 amps/50v.

Sounds like my dinky little hub alternator will barely warm it
up. So much for the heat sink requirement....
--
PeteCresswell

"Heat Sink Putty" ?
 

Heat sink putty is old hat.It's been around for many years.
cuhulin

"Heat Sink Putty" ?
 

Per Jimmie D:
Just get a really big rectifier. I have a 5 amp power supply that uses a 20
amp bridge and its bolted to a piece of wood.

That's what I (inadvertently) did. 25 amp/50 volt to handle
about 1 amp/20 volts max.
--
PeteCresswell