simple (ish) 0-130 DC power supply

[ManowarDave]

Hi there,

I'm a complete newb to this board and am after a little assistance with my first major project.

I am trying to put together a variable DC power supply capable of providing 0-130VDC at about 1.5Amps for the purposes of anodizing titanium.

I have not found much in the way of this kind of thing on the web and what I have found hasn't quite answered all of my questions.

The basic design I am working from can be found here http://www.mrtitanium.com/anodizer.html

I am working with a variac rated to 3Amps leading into a full wave bridge rectifier.  The DC output is then run over a 3300uF 350V Cap to be smoothed before going to the anode and cathode.  The above article has a light bulb bridging the cap to "take the load" and act a cap drain but the article says this can be replaced with a power resistor rated at 100ohm 200W.

Well I got myself 2 power resistors (50ohm 100W for lack of the former as a single unit) in series.  Now these babies get really hot, and this is what's worrying me.  Are they going to blow?

If I take these resistors out of the circuit then I loose the variable aspect of the circuit as the cap keeps the voltage up with no load on if I need to turn the voltage down with the anode out of the anodizing bath.

Really, what I would like help on is, a) are these Resistors up to the job, b) if not what do I need to replace them with, or c) does the whole thing need to be re-thunk?

Many thanks in advance for your help and patience.

Dave