Re: dumping a lot of heat

On Wed, 04 Dec 2024 13:29:03 -0800, john larkin <jl@glen--canyon.com>
wrote:

I'm thinking about building a biggish rackmount dummy load box. It
would simulate series resistance and inductance. Part of the problem
is that it will need to dump a lot of heat.
>
We are using copper CPU coolers on PC boards, which are great up to a
couple of hundred watts, but I'd like to do a kilowatt or two.
>
https://highlandtechnology.com/Product/P945
>
It would take a heap of expensive extruded heat sinks and fans to get
rid of a kilowatt. At 1 K/W, a pretty good heat sink, that's 1000 degC
temp rise.
>
A small hair dryer can dump a kilowatt. So some sort of red-hot
nichrome coils and a vicious fan might work.
>
I'd prefer to not use water.
>
I wonder if there is some sort of runs-red-hot power resistor.

HVAC heater elements are available, premounted in ductwork.

Typical value 10R xKw. Tap, cut or series/parallel to your heart's
content.

The components to build similar structures, ceramic insulators,
and terminals and coiled resistance wire (of selected tempco)
are all available off the shelf. Punch your own metalwork.

RL