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Old 14th August 2011, 09:28 AM   #71
Zen Mod is offline Zen Mod  Serbia
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naah

it isn't an issue , if you feed them with welding capable driver

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Old 18th August 2011, 08:02 PM   #72
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My heat pipe CPU coolers arrived. They are supposedly good for 125W or so. Mounting them to the heat spreader plate to interface with the amps will be a bit of challenge, as I probably won't be able to drill into the copper heat coupling plate on the cooler for mounting screws without hitting the heat pipes. Creative use of the included CPU mounting clips may be the way to go. Who says you can't do a compact Class A amp?
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Old 18th August 2011, 08:20 PM   #73
jcx is offline jcx  United States
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...as long as you can put it in the next room
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Old 18th August 2011, 08:22 PM   #74
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When I'm finished with it, it'll be quiet. The fans will be inside the case, which will help quite a bit.
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Old 18th August 2011, 11:23 PM   #75
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Wrenchone

Coolers are good for that 125W and more had one on old FX55 now retired and it was on cooling duty for my mosfets till yours truly inverted + - vires


If you got spare mosfet spare 4.7 K thermistor and spare pot themperature controller is easy peasy sorry for chiken scratch.

Thermistor on heat sink resistance drop as heat goes up which make mosfet conduct more fan goes faster
Set pot for fans to tick over just when heat is getting up.

Fans at 75 % of rated voltagge are dead quiet.

You would have to clamp cooler to same plate easy once you rip off the clamping braket and use goop of your choice
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Old 19th August 2011, 12:10 AM   #76
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Wouldn't noise be an issue?
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Old 19th August 2011, 12:17 AM   #77
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Not if you make sure that it isn't.... These are many measures that can be taken for noise abatement, including using a quieter fan, running the fan at low voltage, running the fans inside a well-damped case, etc.
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Old 19th August 2011, 12:49 AM   #78
kevinh is offline kevinh  United States
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Quote:
Originally Posted by VladimirK View Post
Nice term, Nelson, I would also add, for widening a picture, that "tube-osity" will depend also on Ciss and Crss, their magnitude and variation with Vds. When we will approach to Ciss=10pF and Crss=1pF with "stone" parts, tubes for sure will be trashed.


IIRC that term was coined by the Late Harvey "Dr Gizmo" Rosenberg. I think NP may have had his inside joke.
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Old 19th August 2011, 01:57 AM   #79
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For my current project I'm gonna use additional cpu coolers too (CoolerMaster TX2). They're cheap when you buy them used, because the first generation is a faulty design concerning the plastic mounting clips for the motherboard. I'm planning to use the chunks without fans. A no-noise solution with an inside duct (is this the right word for it?) providing a chimney-effect is my favorite.

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Old 19th August 2011, 03:09 AM   #80
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I just powered up one of the coolers on the bench a short while ago - the fan draw at 12V is relatively modest (120 ma), and the noise level is surprisingly low. I have some other coolers of more modest capacity that are real whiners at full tilt (like some list members). Next problem is how to interface the CPU clips to my heat spreaders - noise will be a non-issue.
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