Trimming Down a Power One Supply

[man-bot]

I finally have duffed the power supply on my console so I am purchasing a Power One linear power supply to replace it.  The console operates off of 40v and 48v for phantom power.

The Power One supply is 48v @ 3A so I am hoping I can run 2 feeds off of it to supply the 48v for phantom and 40v for the console power.  What I need confirmation on is trimming this sucker down.

I am assuming I can just use the appropriate resistor between the console feed and the connector which feeds power.  From Ohm's Law I'm looking at V=3*R, so if I use a 2 ohm resistor I can drop the voltage down 6v and use on the onboard voltage trim on the Power one supply to trim it down to the supply 2v to 46v... 40v in the end.

For resistor size I would use P=((IxI)(R)) which would give me 16 watts so I was planning on using a 2 ohm 50w resistor (a bit overkill).

Now I could very well be flawed here as I don't believe the current draw is anywhere near 3A  (more like 1.25a)... so should my calculation reflect the current availabe in the Power One unit or the actual draw of my console? (that would obviously change all of my numbers)

Make sense?  Nothing should blow up?

 

[PRR]

Dropping resistor works when you KNOW the current or are not fussy.

A console's current is not easy to know and usually varies a LOT with signal and other factors.

One of the old Yamas? They just might work "OK" with 33V-44V as long as a huge cap kept the supply changes slow.

You need ?several? Amps at +40V but surely no more than 0.25 Amps at the 48V. Get a small 48V supply just for the Phantom. Then use the PowerOne's trimmer to set it to regulated 40V.