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Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ. |
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In Reply to: Thank you jea48 posted by Cousin Billy on April 17, 2010 at 18:35:14:
JMHO, I would forget configuring the xfmr for balanced power. Single ended will yield the full potential of the xfmr as it was designed and intended.Best isolation is to series the two primary windings and connect them to 240Vac. Secondary windings paralleled 120Vac out single ended.
I also received an email from a gentleman who recommended this;Run the primary's in parallel
Run the secondary's in parallel
Better than balanced, jmho....The only problem I have with this configuration is that the saturation noise is back.
Transformers do hum. When you had the two primary windings in series and only connected to 120V it would be quieter. You were only running the primary at 1/2 its rated voltage.Make sure you got the polarity correct...
Primary parallel for 120V in (1&4) (3&6)Secondary paralleled for 120V out (7&9) (8&10)
Also you know you have to connect one output Line,leg, of the separately derived power source to earth. This becomes the neutral, the grounded conductor. By code it has to connect to the main grounding system of the main electrical service.
The connection of the xfmr Line and earth also becomes the safety equipment grounding conductor connection. A star ground.If you decide to fed the xfmr from 240V you will need to install secondary overcurrent protection on the ungrounded Line, leg, of the xfmr.
If you decide just to fed the xfmr from 120V (parallel primary windings)
you could probably forgo secondary overcurrent protection....I am surprised no one has commented on whether they think the xfmr is big enough for a 140 watt power amp. Does it have enough head room for the amp?
Edits: 04/17/10 04/17/10
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Follow Ups
- RE: Thank you jea48 - jea48 19:26:26 04/17/10 (3)
- jea48, I need more information on the star grounding - Cousin Billy 16:09:25 04/18/10 (1)
- RE: jea48, I need more information on the star grounding - jea48 07:10:11 04/19/10 (0)
- Last question gentlemen, do I still need the 0.22 cap? - Cousin Billy 07:55:31 04/18/10 (0)