Hello everyone... First of all I am a rookie when it comes to electronics just scratching the surface. I have an AC/DC Variac. It works fine but I was given a task of making it into a constant power source that will provide 26vac @ 5amps. I have been looking into different things to accomplish this. I was just wondering if anyone has any suggestions.

 

Better to buy off the shelf than build.
Take a look at this:
http://www.bgmicro.com/PWR1278.aspx
150W, 24v (adjustable ~21v to ~27v), 6.5A. $15.40 + shipping.
[eta]
Oops, this is DC out, and you need AC. Sorry.

 

I wonder who "tasks" out these sort of assignments?

 

OP wants AC, not DC.

OP states "constant power". Is that truly constant power (watts) or constant volts, or constant current (amps)?

I don't know how deep your pockets are, but this might do what you need:

http://www.hammondmfg.com/pdf/PB0230.pdf

DC would be magnitudes easier to work with.

 

Mine is at 24 and it is constantly burning out so we always buy new fuses....it's funny one always off sets the other and make it complicated!

 

Variac is not a good device for this sort of thing, a fixed transformer might be a better place to start. Variacs are auto transformers and do not issolate you from the 120v ( or 240 ) line.