F5 Turbo Circuit Boards

[buzzforb]

Any sort of entry hole or slot will allow for air movement through the case. Trying to direct that air movement is possible, but difficult. Too many holes, and the fan may have trouble pressurizing the case and there will not be as much air flow as a result. Velocity may be the more appropriate word instead of flow on the last bit.

[Variac]

So difficult compared to the fan blowing air at the fins, I'll agree! Velocity would be minimal, depending on the fan capacity, but much better than the air rising based on heat alone. I'm losing enthusiasm, but I should rig up an experiment...

[AndrewT]

Originally Posted by SRMcGee

I'm not well educated in the heat abatement requirements of Class A amps but am planning on building a couple of F5 Turbo V3 amps

Build a standard F5 first.
Find out about the heat requirements.

Then use that knowledge to decide if an F5T V3 is manageable.

[siliconray]

Will heat pipe be helpful in class-A thermal management? it seems that the effeciency of heatsink become lower with increment of it's size..

[curdaddy]

I saw that someone had mentioned using a 2.5A fuse. What determines the size of fuse we should use. I did not see anything about it in the white paper.

Thanks

[Zen Mod]

VA of xformer , C bank ,what sort of soft start , you are using ?

[noSmoking]

hi,
I keep seeing folks post about what fuse to use ,Here's my 2cents form 40 years of building,
The ac side of the transformer is one circuit be it 120 or 220 volts ac,it needs a fuse in this circuit.
The DC side if it's a single voltage it needs ONE fuse to cover the whole load.
If the DC side is using 2 DC outputs you need 2 fuses one for the positive side and one for the negative, each one half the whole load,
Now here comes the figuring each fuse must at least cover it's load ,ohm's law will give you a idea of load current, and then the amount over what is required is your insurance I have seen 25% or more and a slo-blow is x2 it's normal requirement,but in the dc side a fast fuse is best and rated about 10% above what is required,
I have had many amps that oscillate blow the fuse, not the outputs so I use them,For my personal F5 I use the cl60 thermistor and the fuses recommended by Mr.Pass,,,,,,anyone wants to pinch in on there recommended values Please do!!!!!!

[AndrewT]

Mains fuse = transformer VA / mains voltage

[rubofdagreen]

So 2 x 800va =1600 / 120vac = 13.33 amp fuse? Really? Seems awfully big.

[jdkJake]

Originally Posted by rubofdagreen

So 2 x 800va =1600 / 120vac = 13.33 amp fuse? Really? Seems awfully big.

If you are using two separate transformers, I would fuse each separately.

A 6.5A fuse is not uncommon. Even at 5x20mm.