I need to rewire my LM4780 amp to eliminate a ground loop issue. I have an Avel Lindberg 330VA 25Vx25V that I need to configure to have a center tap, in other words, 25V-0-25V. Please take a look at this schematic and tell me how to wire this.
If I wired both primaries and secondaries in series, I'll end up with 230V for the primaries, and 50VAC for the secondaries. I only need 25VAC (rectified into 35VDC) for my amp. Do I use this wiring scheme and plug it in to get 25VAC, since we have 120VAC in the US? Or do I keep the primaries in parallel and wire the secondaries in series?
Thank you for your help.
If I wired both primaries and secondaries in series, I'll end up with 230V for the primaries, and 50VAC for the secondaries. I only need 25VAC (rectified into 35VDC) for my amp. Do I use this wiring scheme and plug it in to get 25VAC, since we have 120VAC in the US? Or do I keep the primaries in parallel and wire the secondaries in series?
Thank you for your help.
An externally hosted image should be here but it was not working when we last tested it.
You have dual primaries so that you can put the primaries in series or parallel for 115/230VAC. The secondaries are the same way (25VAC @ double the current, or 25-0-25).
So, the answer to your question is to put the primaries in parallel and the secondaries in series. You should definitely read up on how transformers work, though, so you understand why you're doing this.
So, the answer to your question is to put the primaries in parallel and the secondaries in series. You should definitely read up on how transformers work, though, so you understand why you're doing this.
Also read through these web pages if you haven't already:
http://www.zero-distortion.com/techno/powersupply/powersi.htm
Good info. and it will show you the different ways you can build a +/- linear supply.
http://www.zero-distortion.com/techno/powersupply/powersi.htm
Good info. and it will show you the different ways you can build a +/- linear supply.
Use the top left picture for the primaries and the bottom right for the secondaries. The tie piont fo the series coils needs to go to the Pwr supply ground (not the same as chassis ground) and you will have to use a bridge rectifier or a descrete bridge.. You will not be able to use the descret diodes in BrianGT's pwr supply board with out jumpers or modification...
Picture paints a thousand words. I use the same tranny from avel. Picture shows how I wired it for brians chipamp.
http://www.briangt.com/gallery/nigc-budwiser/PICT0066
http://www.briangt.com/gallery/nigc-budwiser/PICT0066
hongrn said:
Is the end application a BrianGT kit or a home brew design?
And going form dual secondary to center tap is generally not the way to troubleshoot ground loops.
May I please ask you to elaborate on the end application (bridge rectifier scheme) and the motivation for change( Ground loop?).
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