VA Tech fusor team visit

[Lee Hall]

I don't think this is a problem nor does the rest of my team, but we're looking at getting 2 or so 50 kOhm, 225 W or 175 W resistors since we couldn't find any fitting the bill at 100 kOhm, but is there a problem with putting 2-225 W resistors in series? Just wondering about the overall power rating, but like I said, we just think the main thing to look at is the resistance; I just wanted to make sure. Thanks!

[Doug Coulter]

The only issue with them in series is they are big and bulky, so you probably need to figure out a way to support them to do that. That's where it gets a little tricky -- can't use plastic, or at least not near the resistors, it'll melt. You might make a plastic base to hold them, but then use wood for the R's to rest on (at just a couple of points). At least if you get it too hot, you get some warning that way.

Power rating of two is twice one (assuming they are the same R and so split up the dissipation evenly).

100k might be on the small side for a new system break-in -- you'll have to be extra careful, and hope that the peak current won't still trip the arc detector in the supply -- and shut you right back down. I don't have the info on your spellman on how big the R has to just eliminate the arc trip sense, but it's probably in the couple hundred K range.