Transformer Search

Grant Stockly grant at
Sun Jan 14 17:30:52 CST 2007

>The original power supply for the 680 was WAY undersized...
>You can get a pretty good idea of the transformar rating from
>the size. (or weight) Look through the catalogs for something
>of similar size and use it's power rating to calculate how much
>the original transformer could have provided.
>In the 680 almost all  of the load was on the 5 volt supply.
>(and +9 unreg for option cards)

I want to get as hefty a power supply I can and still fit in the 
enclosure.  The 680 was often modded to have two transformers in 
parallel.  I would be interested in doing that depending on the cost.  I 
was hoping someone would have a manual from MITS that mentions the VA or 
output on each of the 2 secondaries.

Would knowing the resistance of any of the coils tell me the current 
capacity?  Probably not without knowing the number of coils?  As long as 
the replacement has a higher output than the origional I'm happy.

>Are you doing an exact recreation or using more modern parts?

I don't know what you mean.  About as exact as the 8800 kit I did.  Except 
maybe a little more since there isn't room for a switching power supply.

The 680 isn't as well known, or nearly as available on the 
aftermarket.  Thought it would be a good one to preserve the software.  : )


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