Convert CM15A from 120V to 220V

[GungHo]

Hi,
I have now received my CM15A from USA and
are going to convert it to 220V.

I can either use a external transformer or exchange the
allready soldered transformer on the board !

I would prefer to change the transformer on the board
but I am affraid that the opto couplers will be damaged.

Any advice ?

[Dave Houston]

"GungHo" <je.johansson@gmail.com> wrote:

>Hi,
>I have now received my CM15A from USA and
>are going to convert it to 220V.
>
>I can either use a external transformer or exchange the
>allready soldered transformer on the board !
>
>I would prefer to change the transformer on the board
>but I am affraid that the opto couplers will be damaged.
>
>Any advice ?

I think an external 220:120V step-down transformer with a bypass cap is
safest. Otherwise, there are a few other components that you will need to
change.

There's a schematic at
https://gullfoss2.fcc.gov/prod/oet/forms/blobs/retrieve.cgi?attachment_id=347598&native_or_pdf=pdf
if you don't already have it.