Apr 302019

While cleaning the storage I found a very interesting power supply made by Sanwa and marked SNW-7E which works with 110 or 220V

The model SNW-7F is the same model working with only 110V

It’s a very nice and compact power supply ( with a tendency of getting really hot!) and I learned that it was used on the most famous japanese superguns .

When I powered it up it worked but on the -5V line I got -7,5V .

I decided to try to repair it and fortunately the -5V was given by a 7905 regulator with few parts around.

I immediately noticed that the regulator didn’t regulate at all since it passed exactly the same voltage on the input on its output.

Replacing it with a new 7905 fixed completely the problem



it turns out that this power supply is just a rebadged version of the RT-85A model made by Taiwanese company Meanwell