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Internal PSU MOD

Posted: Oct 30th, '16, 23:58
by hofmann25
These photos are of the YOCTO but this will work with the NAVA...

This is what I did with the fantastic help from Jeroenbvo

This viewtopic.php?f=16&t=331#p2009 thread helped me alot and so did http://imgur.com/a/IeBch#4

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This is the NAVA PSU Circuit.
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Using this from Mouser http://au.mouser.com/Search/ProductDeta ... -VPT30-830
Primary
1) Connect Gray and Violet to each other and insulate the joint. You don't need it further on.
2) Blue and Brown will go to your 115 V/230V input. It doesn't matter here which one goes where. Connect Blue to Blue (Neutral) and Brown (Live) to Brown. You'll want to put your power switch on the Brown line.

Secondary
This one you want in series as well, so you connect;
1) Red to Orange, and this joint is now your 0V center tap which will be connected to the sleeve of where your wall adapter was
2) Black for example goes to the center of where your adapter was.
3) Then Yellow will go to the center of your two added 1N4004's. (Add 2 x 1N4004 and twist them together.
Solder the anode of one to the anode of D2 - Yocto/D110 - NAVA and the cathode of the other to the cathode of D1 - Yocto/D109 - NAVA
This way you change the PSU into a full wave bridge.

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Earth from 230V side goes straight to chassis. And that point is also where you hook up one side of the ground loop breaker.
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Test Tip: Just wire the transformer up out of the case and not connected to the Yocto. Insulate all 240V connections. Plug it in and with a multimeter (Set for AC) measure between Red/Orange and Black, you should have more or less 15V AC. Measure between Red/Orange and Yellow and again you will have more or less 15V AC.

Then connect the IO board to the transformer and do your tests on the main wires you connect to the main board like you did for the PSU build in the build guide.

Ground Loop Breaker
2 x 1N54xxx
1 x 10 Ohm 5 Watt
1 x 100nF for filtering RF noise


It's not that hard really when you know what windings go where on your Transformer...

If you have the information share it :D