cheap 200A AC to DC power supply?

That's under 6 cents per watt, about a fourth the going rate for a cheap power supply.

What's the application? It's going to dump a lot of heat somewhere.

John

Have you calculated the coefficient of performance of 10 thermoelectric heat pumps? 0.15 or so is typical with liquid cooled heatsinks. Much less otherwise.

These are generally TOTALLY USELESS above the one watt level.

Because the temperature RISE above their heatsink over ambient will GREATLY EXCEED their temperature drop across the module.

See

for a detailed analysis.

Would a vortex cooler work instead?

--
Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
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For what purpose?

that's a 3.4KW dc powersupply, why would you want to power that from 120V something like that typically gets a 240V or three phase supply,

if you need active cooling a mechanical heat pump may perform better. probably cost less too.

--

Bye.
   Jasen

Tony (remove the "_" to reply by email)

The filter needs to be pretty good, otherwise the quickly fluctuating temperatures cause mechanical stresses which severly reduce the lifespan of the Peltier elements.

That's bollocks. You'll have to have a huge LF ripple to kill your TECs. Any decently (read not completly screwed) designed PWM supply will give you as long a lifespan as a DC battery.

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Thanks,
Fred.

That's what I mean. You'll need a real supply, not just a rectifier and a few big caps.

On a sunny day (17 Nov 2006 20:48:47 -0800) it happened snipped-for-privacy@wwc.com wrote in :

Can you put the pumps in series? If so rectify 120V AC gives you 169.7 V DC, 10 x 17V pumps in series at

17A total, riplle depends on the cap size. 4 20A 400V diodes, one huge electrolytic.

If you cannot put the pumps in series you better use separate power supplies. If you can, modify some PC power supplies, so these give 17V, 10A (170VA). (put 12V in series with the 5V). That will be a cheap solution, PC power with 12V > 17A can be found for less then 50$ each, discount for 10 ;-)

But your data is confusing, at one point you sat 17A, then 10A. So check again what you have.

Even that will do unless you have a so small cap that the ripple is more than 5-10%. The pb associated with ripple are:

- loss of cooling efficiency

- if your ripple is too low in frequency WRT thermal inertia, like when you're thermal cycling your TEC with a ON/OFF thermostat then you may reduce its life.

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Thanks,
Fred.

Nope. Ripple is even worst, because the ripple troughs HEAT much more than the ripple peaks COOL.

Your useless COP then becomes an outright joke.

--
Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml   email: don@tinaja.com

Please visit my GURU\'s LAIR web site at http://www.tinaja.com

--
Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml   email: don@tinaja.com

Please visit my GURU\'s LAIR web site at http://www.tinaja.com

The point remains that all he will end up with is a giant HEATER. A bonfire would be a lot faster and cheaper.

Thermoelectrics are utterly useless above a very few watts.

--
Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml   email: don@tinaja.com

Please visit my GURU\'s LAIR web site at http://www.tinaja.com

A co-worker was using one of those in car coolers as a small fridge, off a

12 V auto battery charger. It wasn't cooling much. I added a large electrolytic (souvenired from an old printer) and it started to freeze up. We ran it on the 6V setting after that.

Sure that's a lot of heat and inefficient is the keyword that stick to TECs. But I don't know if it's useless or not; this just depends on the application.

--
Thanks,
Fred.