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Originally posted by koslov
Looks very neat, but expensive. Also, the highest rated unit can only handle a 172W pelt. But none of the units are capable of supplying Vmax for 24V TECs. The best they can do is 18V. I would have preferred if the voltage was adjustable, so you can operate the TEC at full power if needed. For 15V pelts, you have to use the 12V model, 3V under Vmax.
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It looks to me like the VPC-225+ is spec'd to handle a 226 Watt TEC at Vmax. The website is ambiguous though. The VPC-225+ may be vaporware.
Quote:
Originally posted by koslov
[b]
What I find a little funny is this quote:
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What it doesn't do. . .
Waste power - the VPC controller supplies only the amount of power necessary to do the work (cooling). It does not take a higher amount of power from the power supply and reduce it, rather it only takes the amount necessary, allowing for cooler computer operation.
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This seems to imply that no power is wasted, or at least very little. Well, what is that big, honkin' heatsink for on the larger models??
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Suppose power to a 226 Watt TEC is being provided through this thing at Vmax, that's 365 Watts controlled by the VPC-225+. If the VPC itself is dissipating 10 Watts, I'd consider that a very small amount relatively speaking. With only passive convection to count on for cooling, that heatsink looks reasonable to me.
Quote:
Originally posted by koslov
What do you think? Overpriced? Can a DIYer build one significantly cheaper?
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At $106 + shipping, I'd say the price was 'reasonable'.
It would certainly be possible for some to build an equivalent device cheaper. Particularly if packaging it nicely were not an issue. I think most would have a difficult time doing it for less than the VPC price though.
The biggest problem I see is the way it operates. My understanding, (based on an article at Overclockers some time ago) is that these things cycle the power at a very slow rate. (A few seconds on, a few seconds off.) TEC manufacturers recommend against this type of control. In fact the manufacturers recommend keeping the 120 Hz ripple of 'DC supplies' below 10%.
The reason the manufacturers recommend against ripple and turning the supply on and off at a slow rate, is that these conditions age the TEC prematurely due to excessive temperature cycling. Personally, I'd avoid setups that could lead to early TEC death.