Dummy Load

[Jim1428]

Nope. It is a single 50 I think.......or 100 watt ceramic resistor.



10% is a typical tolerance and the load should measure between 45 and 55 ohms and show 1.1:1. I have started looking at ceramic chip resistors on a LARGE heatsink and have bought a pair of 100 ohm 800 watt chip resistors. I mounted each of them on their own heatsink mounted back to back and wired in parallel. Makes a NICE kilowatt dry load. More if I put a fan on it. IIRC I got the resistors from Florida RF on Ebay.

I'm also interested in using these chip resistors for a dummy load.

My concern is they won't be able dissipate large amounts of power for an extended period of time. With the device being so small I don't think it can dissipate the heat fast enough.

I have a 16x10x1/4 inch cooper heat spreader bolted to an aluminum heat sink I am planning to use.

 

[Captain Kilowatt]

I'm also interested in using these chip resistors for a dummy load.

My concern is they won't be able dissipate large amounts of power for an extended period of time. With the device being so small I don't think it can dissipate the heat fast enough.

I have a 16x10x1/4 inch cooper heat spreader bolted to an aluminum heat sink I am planning to use.

Ceramic chip resistors are fine for dummy loads as long as they have proper connection to the heatsink. You have the right idea about using a copper spreader bolted to the heatsink but you must have VERY smooth flat surfaces. FWIW a copper spreader half that size is quite adequate.

 

[Jim1428]

Ceramic chip resistors are fine for dummy loads as long as they have proper connection to the heatsink. You have the right idea about using a copper spreader bolted to the heatsink but you must have VERY smooth flat surfaces. FWIW a copper spreader half that size is quite adequate.

The original plan was for a 3kw dc-70cm dummy load but I ran into some problems so the project got put on hold, I also have a tendency to go overboard sometimes.

 

[Tallman]

The original plan was for a 3kw dc-70cm dummy load but I ran into some problems so the project got put on hold, I also have a tendency to go overboard sometimes.

Isn't anything worth doing is worth overdoing? I call it "Diesel Design" where everything is mechanically over designed.
Needless to say I never successfully designed a airplane. It would taxi like a bat out of hell, and take heavy bumps that would crush most landing gear.
Maximum Service ceiling "Zero feet above ground level."