Simple question regarding converting chipamp from 110V to 220V

[maurycy]

I have a LM3875 based stereo chipamp that I have built based on BrianGT's kit. It is currently setup with a small 42 CVT trafo and works just fine. This is in US so it runs on 110V. Now, if I were to take this amp to Europe, would it work just by replacing 110V 42CVT trafo with 220V 42CVT one or I would need to make more changes to the components on the PCB?

Thanks.

 

[rhysh]

All that is needed, is to change the transformer to a 220v one, and maybe the onboard fuse, if there is one, and if it is 110v rated.

Rhys

 

[maurycy]

Thanks rhysh for your reply. I was thinking that changing trafo would be enough but since my knowledge about electronics is very limited, I wanted to be sure.

 

[rhysh]

No worries 😉 What i have mentioned are the only things that will need doing, just check the AC switches, Fuseholder etc and make sure they are rated over 220v. Just a precaution.

 

[AndrewT]

Hi,
your transformer may already be suitable for both 110/120Vac and 220/240Vac.

Does it have a single 110/120Vac primary winding
or
a dual 110/120Vac winding wired in parallel?

 

[maurycy]

I have no idea Andrew. I got it from ApexJr. Here is the description:

Chia Yu Co Ltd
Input: 2 X 120Vac 50-60Hz 3" Dia X 1 1/2" Tall
Output 42Vct 21V- 0 - 21V 80VA

 

[rhysh]

Yes, you should just be able to wire the inputs in series.

 

[Redshift187]

Which means you don't need a new transformer, you just need to wire it differently.

 

[AndrewT]

Yes, you CAN wire the inputs in series.

Which means you don't need a new transformer, you just need to wire it differently.

a dual primary is effectively universal for use anywhere in the world with 110/120Vac or 220/240Vac.

 

[rhysh]

a dual primary is effectively universal for use anywhere in the world with 110/120Vac or 220/240Vac.

Im aware, i just didnt want to get blamed for anything blowing up


😀

 

[maurycy]

Thanks for helping newbie.

I have the following wires for the mains:

black
black
brown
white
white
blue

Currently, I have black-black-brown tied together and white-white-blue tied together for 110V. How do I re-wire it for 220V?

Thanks.

 

[rhysh]

You are best off looking at the side of the transformer, at the wiring label and telling us which wire is which, to avoid any possible risks.

Rhys

 

[maurycy]

Will do once I get back from work. I will post a picture or schematic if available.

Thanks.

 

[rhysh]

Dont worry about the picture, the coulor codes will do.

Rhys

 

[maurycy]

Finally had a chance to take the case apart, un-glue the trafo and take a look at the code label. Here it is:

White x2 0V
Brown 120V
Blue 0V
Black x2 120V

The other end is:

21V Red
0V Black
21V Yellow

 

[pacificblue]

So for 230 V connect transformer blue to the mains cable blue, transformer black to mains cable black or brown and transformer white to transformer brown.

 

[maurycy]

Thanks to all who replied.