PC fan on 30 volts

[Gustav]

Originally Posted by cabking

Gustav, I recon a couple of ice cream cones through the windscreen could do the job.....they would have to be double scoop size obviously.....
That just leaves you to work out how much to bite off the end.......:004

That sounds a bit technical,so far all i've got is a fairy liquid bottle jammed in the grill with a plastic pipe stuck to it,it's sure to catch on.

[BrianG]

Lol, sounds too complicated. Why not have a small tank of liquid Nitrogen? Or use a Peltier cooler?

[Gustav]

Hmm,liquid Nitrogen,sounds like a plan.

What i really want is little mini watercoolers on the FETs,with a little pump to send coolant to a little radiator in the front grill.You're a technical guy Brian,can't you sort that out on my MGM? Oh and it needs to weigh less than 100 grams too:018:

[BrianG]

Originally Posted by Gustav

Hmm,liquid Nitrogen,sounds like a plan.

What i really want is little mini watercoolers on the FETs,with a little pump to send coolant to a little radiator in the front grill.You're a technical guy Brian,can't you sort that out on my MGM? Oh and it needs to weigh less than 100 grams too:018:

Watercooled, eh? Let's see.

- Radiator
- Attach a 80mm, 12v fan to the radiator.
- Waterblock to attach to your FETs using thermal epoxy.
- Of course you need a pump.
- And lastly, you'll need some tubing.

However, I don't see this weighing 100g - more like 900g+.

IMO, just get something like this.

[Gustav]

Yeah! Now that's what i'm talkin' about.

I was wondering how the cooling tubes on the shulzes transfer heat from the FETs,they just look attached to the sides of the PCB,Just a thermal compound or mat or something? Those little waterblocks would be the buisness though.

[BrianG]

The FETs used in most ESCs I've seen are just a huge array of surface mounted devices (no mounting "tab"). Therefore, they mostly use the PCB traces as a heatsink. Since there are so many FETs, the PCB is nowhere near big enough.

Schulz apparently attaches heatsinks to the sides of the PCB where the traces end.

Other designs seem to have multiple FET PCBs stacked on top of each other with the heatsink on the top layer. Each layer has the PCB above it laying on top of the FETs so the heat transfers to the layer above it (that sounded confusing even to me). BKs and Quark seem to do this. They have to make sure that each PCB firmly touches the FET below it or the heat won't be conducted as effectively.

[Edit]: Personally, each design leaves room for error and some FETs aren't cooled enough. I would like to see a slab of Aluminum between each layer of FETs, maybe machined so there are little raised squares where the actual FET is to prevent shorts. Each slab is then attached to a heatsink on the sides. Each layer gets cooled more or less equally that way. Although, it would be substantially larger, weigh considerably more, and be more expensive...

[Gustav]

I always think the stacked designs look like they must suffer with low surface area:volume ratio,i wonder how much hotter they are in the middle.