Unknown Transformer

C

cne

New Member

• Aug 17, 2011

• #1

Hello,

I pulled a transformer out of a piece of equipment and I need to know the current rating. I tested it with a voltmeter and the output is 40vAC center tapped. The fuse on the device it came from is rated at .5A. The primary is 120vAC.
My question is, what is the current rating of the secondary?

Thank you in advance,
Cameron

 

P

Pommie

Well-Known Member

Most Helpful Member

• Aug 17, 2011

• #2

Measure the size/weight and find a similar transformer to find the VA rating. Divide the VA rating by 40 to get the current.

Mike.

 

crutschow

Well-Known Member

Most Helpful Member

• Aug 17, 2011

• #3

Since the primary fuse is rated 0.5A it's likely the transformer VA rating is no more then 60VA. That would make the current rating of the secondary a little more that 1A.

 

C

cne

New Member

• Aug 18, 2011

• #4

Thanks for the reply. I think I will call it about 1A.

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Aug 18, 2011

• #5

cne said:

Thanks for the reply. I think I will call it about 1A.

Click to expand...

I'd be more inclined to call it 0.5A - the mains fuse is usually considerably over-rated, to prevent it blowing with the switch-on surge.

 

alec_t

Well-Known Member

Most Helpful Member

• Aug 20, 2011

• #6

.....and if you do call it 0.5A, try running it with various test loads up to that figure and checking at each stage for signs of over-heating of the tranny.