Replacing old transformer

[monika_v]

Hi,

I have a old dual power supply, a Tenma I believe, which has a dodgy rattling burnt-out humming transformer which I'd like to replace.

Since I have a 'suitable' SMPS RPS-400-36 252W 36V 7A laying around doing nothing I thought I'd replace the transformer with this. These are more energy efficient for starters and since the PSU is 30v 5A it should be man enough - would be significantly lighter too.

Clearly I'd have to check the spec of the transformer first and the windings etc...

Would there be any issues with doing this?

Thanks

 

[cupoftea]

Your RPS gives a 36V 11.2A output....so if thats what you want, then youre fine.
But i thought you want a "dual" output?
And i thought you want "30V"?....RPS-400-36 gives 35 to 37V.

Beware of giving it the requisite cooling..as per datasheet

Remember mains txfrs are much more robust to overloads.

RPS

https://www.meanwell-web.com/content/files/pdfs/productPdfs/MW/RPS-400/RPS-400-spec.pdf

 

[monika_v]

Hi @cupoftea ,

Yes, cooling is something I hadn't considered but is fortunately easy to add if necessary.

The front panel indicates it is a 0-30v 5A supply so my thinking is that the current supply from the transformer will be more than this to allow the regulation between the stated voltage - I would not expect the transformer to provide less than 30v...

Will have to explore but not sure at the moment whether the transformer has multiple windings, one for each of the dual supplies or a single winding for both supplies. 11A Should be sufficient for both supplies though. Not sure whether 11A is a little tight in the unlikely event of both dual supplies drawing their max 5A...

One of the plus points with the RPS-400-36 is that they have OL / OC / OV protection built in as well as a fan supply if necessary. Since this is also a medical grade PSU, they are also quite well manufactured.