rheostats

[mcrites]

I had a rheostat die on me. If I turned it all the way to one side, the fan will come on full blast, but if I turn it a little to the other side, the juice to the fan will be blocked. I do not understand what happens when a rheo dies. Esp, if it just turns into an SPST. How does exceeding the rated power dissapation (watts) kill the resistance in the rheo? Thanks for any help, If you can, at least provide a link or 2 that can explain this to me. Thanks..

[TruckChase!]

Current passes through the rheostat.. their wattage rating is just how much they can handle regulating. If your fan is trying to draw too many watts, it'll fry the components because that rheostat wasn't made to handle that kind of load.

[zoopa_man]

LOL I've seen this happen in the palm of my hand literaly. I goofed around with rheo's a lot. There's little coils inside and when you kill the rheo all the little coils get melted and smoke, stinky yuck. Anyway...There are many different rheos that you can buy form specialty electronics stores (NOT RADIO SHACK) Try looking on the net that will handle the load you want to put on them.

[mcrites]

yeah, i got some 5W ones from caseetc.com. I think my fans are 5.1 W, but i dunno of any other sites, i cant seem to find any. Do you have any with higher ratings that you would recommend? Or is 5W in your opinion good enough?

[TruckChase!]

I'd try to find something with a little more headroom. I know a couple of local electronics shops near me carry them up to like 20 watts... maybe you have something like that around you.