Proper resistor for external PSU

mrjack

VIP Member
I have a PSU which has a +115V rail which powers a +115V fan. I just got a "new" +100V fan (aluminum body, baby :D). I was just wondering what's the proper resistor to turn +115V to +100V 0.19A. When I calculated it I got the result (when using 115-100=15V)

15V/0.19A=78 Ohms.

But now what I need to know is what Watt rating should it be?
Which is the correct one or do you have your own suggestion since it was quite a while ago that I had to calculate resistance. :P

EDIT: I just used Riedon's resistance calculator and got the Watt rating of 2.85W.
 
Last edited:
[-0MEGA-] said:
Im still kinda confused one what your doing...


-Geoff

I'll explain it in phases

1. I have a +115V fan and a transformer (+115V rail) which powers the fan

2. I recently got a +100V aluminum fan, which looks good, and I want to use the same transformer to power that fan

3. The problem is that the +100V is overheating and the plastic bits on it might melt since it isn't completely made out of aluminum and the motor starts to smell burned

4. What resistor should be installed to get +115V down to +100V 0.19A?

Did you understand now?

I did some calculating and it seems like a 3W 82 Ohm resistor would be enough, but I'm not completely sure.
 
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