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Old 30th September 2009, 09:28 PM   #81
fritz39 is offline fritz39  United States
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Quote:
Originally Posted by fritz39 View Post
I'm not sure how you're getting 27V out of an 18-0-18 transformer
I made this comment because you shouldn't get more than 18*1.414=25.5V.
For the F5 PS there is a diode drop and a small drop across the series resistors.
That should put you in the 24-25V range. You must have closer to 19V on the
secondaries of the transformer. No biggy I just found it interesting.
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Old 1st October 2009, 01:52 AM   #82
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Did get the resistors in the B1 and got it back in my current system. Its really terrific how it sounds with all kinds of music. Dynamic and musical. I will try putting the F5 back in there tomorrow. Thanks

122v coming out of the wall probably pushes it above 18v, right? I don't remember testing that.
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Old 1st October 2009, 04:36 AM   #83
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F5 I like
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Old 1st October 2009, 08:55 AM   #84
AndrewT is offline AndrewT  Scotland
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Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by fritz39 View Post
I made this comment because you shouldn't get more than 18*1.414=25.5V.
For the F5 PS there is a diode drop and a small drop across the series resistors.
That should put you in the 24-25V range. You must have closer to 19V on the
secondaries of the transformer. No biggy I just found it interesting.
a three per cent regulation 230:18Vac transformer will give {Mains voltage / 230 * 18* 1.03} when the secondary is unloaded.
An eight per cent regulation 230:18Vac transformer will give {Mains voltage / 230 * 18 * 1.08} when the secondary is unloaded.
i.e. expect between 17.4Vac and 21.5Vac from an 18Vac transformer.
17.4Vac can give ~24Vdc when rectified, smoothed and half a volt diode drop due to low current demand.
21.5Vac can give ~30Vdc when rectified, smoothed and half a volt diode drop due to low current demand.
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regards Andrew T.

Last edited by AndrewT; 1st October 2009 at 08:58 AM.
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Old 2nd October 2009, 02:33 AM   #85
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F5 I like too. I readjusted the second monoblock to much better measurements, just under .6v on both mosfets reading almost identical and dc offset just under 30mv. Hooked up to the B1 and the cdp and it surpasses my current setup. Thanks for all the help. Couldn't have done it with out the shared knowledge that exists here.
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