[time-nuts] Cheap Rubidium

[WarrenS]

>The problem with cooler chips is ...

The Real Problem seems to be some don't have much practical sense.
A peltier would work GREAT, (along with many other simple active ways).
You don't need to make a refrigerator with it.  
You just need to just keep the temperature of what it is attached constant.
One way to do that, is to mount one side of a  peltier to a working unit's heat sink
AND Adjust everything so that the nominal power into the peltier  is near ZERO.
Now it can cool or heat the THING it is attached to just a little to make up for the room temp variation.

Then some simple person may ask why bother with the cooling side at all, 
why not make it unipolar and just use the heat side, 
by using a little larger heat sink on the thing or running the nominal Temperature a little higher?

ws

*********************

Hi

THe problem with cooler chips is that the heat still has to go somewhere. On the "other side" of the device you need to deal with both the original 10 or 20 watts plus the heat from the cooler. To move 10 or 20 watts and get a significant delta T you need a pretty big cooler chip. Since they are low voltage, that gets you right back to lots of current and thus magnetic fields. 

The idea of putting the cooler a distance from the cell and coupling with moving air is still an option though. 

Bob


On Dec 24, 2009, at 9:28 AM, Steve Rooke wrote:

> I wonder how peltier devices would work for this application. Coupled
> with a temperature feedback servo they could be used to heat/cool the
> rubidium. Does anyone know if they have any electromagnetic field
> issues with them, the ones I have seen seem to be completely enclosed
> in aluminium which should act as a Faraday cage. They have the
> potential of providing a large thermal transfer capability compared
> with passive devices.
> 
> 73,
> Steve
> 
> 2009/12/25 Joe Gwinn <joegwinn at comcast.net>: