[sdiy] MKS-70 Switch internal transformer from US 117 to UK 240

random variate randomvariate at hotmail.co.uk
Wed Sep 15 17:16:29 CEST 2010


Thanks Graham for the pointers, very much appreciated.

I'll check the power filter board very carefully regarding the fuse.

Oh, on the 220v point, I was just thinking it would give some headroom if the fuse was a 250rated - I'm no serious leccy tech, so was thinking aloud.

Thx





On 15 Sep 2010, at 12:11, Graham Atkins <gatkins at blueyonder.co.uk> wrote:

> On 15 Sep 2010, at 11:57, random variate wrote:
> 
>> Hi there everyone, newb here
>> 
>> I'd like to get rid of my step up transformer wart on my US model MKS-70 and have checked the internal transformer:
>> 
>> Currently soldered on 117v point and 0v point
>> There are 220v and 240v winding points
>> 
>> The power filter board has a 250v rated glass fuse
>> 
>> 1.  So, is the switch as simple as de/resoldering from the 117v point to either the 220v point or 240v point
>> 
>> 2. Would anyone suggest using the 220 rather than 240v point?
>> 
>> 3. I'd also like to swap out the 2 pin US square power socket for a Euro 3 pin IEC 'kettle' socket - there's no grounding though? Should I just leave the grounding or would you suggest a chassis pin?
>> 
>> 
>> Advance thanks
>> 
>> Tim
> 
> Hi Tim, the UK is 240V, why would you want the 220V tap ?. Yes, use the 0V and 240V primary. Connect the ground on the IEC socket to an earthing point on the chassis.
> If the fuse is in the primary circuit don't forget to change that as well. The VA rating of the transformer in theory will remain constant so if you double the voltage you need a
> fuse of half the current rating of the existing one. Don't forget to get the right type (If there is a T in front of the current rating it is a delay fuse).
> 
> Graham
> 
> 




More information about the Synth-diy mailing list