Hello,
Here is an easy project involving a BNC connector, small plastic box and eighteen 100-Ohm 2W resistors. Total resistance is of course 50-Ohms. What is the total power handling? ;D
(http://radiopreppers.com/images/dummyload.jpg)
Gil.
Quote from: gil on May 22, 2017, 09:37:44 AMWhat is the total power handling? ;D
I'll comment because I've seen quite a few engineers miss this one. You've got 18 resistors rated for 2W so 36W...for a short time. Actually, the the pulse handling ability of the resistors is much more than 2W. I wouldn't hesitate to put a few 100W dits or dahs into it. But then I would wait quite a while for it to cool down.
The real limitation is because the resistors aren't in open air but a plastic box. The continuous power rating will be whatever heat can pass through that box into the air without melting the box ;) . Guessing the size of the box and using a little rule of thumb, I estimate you can't leave it cooking key down with more than 5W before the box starts to get soft :o
I estimate you can't leave it cooking key down with more than 5W before the box starts to get soft.
A few holes might be in order ;D
Gil.