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Old 03-09-2007, 08:30 PM
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ballaratdragons (Ken)
The 'DRAGON MAN'

ballaratdragons is offline
 
Join Date: Jan 2005
Location: In the Dark at Snake Valley, Victoria
Posts: 14,412
Quote:
Originally Posted by Doug View Post
Ken, ahh well anybody really: how certain are you that a controller is needed????? Obviously some have them, but do the really need them?
I mean a low wattage heater is simply not going to melt down the Object glass. I don't have one, I don't need one so why do others? I inserted a thermocouple between the heater ( an Astrozap) and the corrector lens assy initially, and watched. Before there was much of a temperature change, the heat lost by exchange equalled the heat input by the pad::: no dangerous heating of the corrector. The lower the ambient temp, the more power was needed, but certainly no controller.
BTW, using a series resistor to control what? Temp? Current? is gross inefficiency. At a minimum, use a pass transistor, but really try using your heater without a controller. If your heater is about 20 watts or so as also indicated by Bert, you will find that you will not need a controller.
Ok, thanks Doug.

The 'Pots' were just to lower the temp if I turned the power up to 18v or 20v etc.

I'll make the heater strips work without pots then, but I'll still need one for the fan. At 15v it seems like its about to fly off into orbit!!!
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