I decided to buy a few Mean Well switching power supplies the other day as I found them on sale for SEK 20kr each (some USD $2) to see if I could modify them - I decided to buy them because they were cheap and I could use them for other stuff if I couldn't rewind them.
I have successfully modified a RID-50B (5V@4A and [email protected]) (http://www.meanwell.com/mw_search/RID-50/RID-50-spec.pdf) to get [email protected] and 198V@60mA, but it was more complicated as the secondaries were put in between the primaries, but it was quite easy to modify anyway. Now I need to go and buy some more transformer tape as I ran out of mine. It was easy to remove the outer primary winding and I could reuse most of the tape that I found inside the transformer, even the outer tape was reusable. I did remove part of the 5V winding and didn't put it back so I only got part of the original current, it was wound both underneath and on top of the 24V winding that I replaced. Without load I get some 210V and with 3.3 KOhm load I get 198V. It was easy to modify the core as it was not glued together at all, just kept in place by some turns of transformer tape on the outside and then some waxy substance in the middle of the core, the sides were not glued at all! Adding 140 turns of 0.25mm enamelled copper wire was quite easy and it fit fine on the core with enough layers of transformer tape to keep the isolation intact (I put on two more layers to be sure to not get any isolation problems but I am not sure if it affects the transformer negatively in any other way. I only had UF4007s (probably not the best ones but they work) to use as rectifiers and those together with a 22uF/400V capacitor was enough to keep the hum down below 150mV, I haven't added any other components to the output for now but it looks promising. Thank you John for publishing your modification, it made me brave enough to take the step to try it myself! Now I just wish I could find those wall warts or anything similar here in Sweden. What rectifiers did you use? /Martin -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/cfc948d0-4054-47bc-93c3-adf7c2121743%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
