Can I Use this Trafo ??

dougfunnyBR · 03:05 PM

I have a really big 50 - 0 - 50 trafo here with me, but i need +-70 for 2x400w amp...
can I use this trafo for +-70 like in this circuit ?

sorry for my poor english, i'm brazillian

dougfunnyBR · 12th February 2011, 03:07 PM

[img=http://s1.postimage.org/j6afz5tc4/100503_14mg.jpg]

boyofwax · 12th February 2011, 03:13 PM

Yes you can use it. If you look at the picture you can see they used the same trafo as you've mentioned.

dougfunnyBR · 12th February 2011, 03:20 PM

yeah, but can i use for 2x +-70 ??

boyofwax · 12th February 2011, 03:57 PM

Quote:

Originally Posted by dougfunnyBR

yeah, but can i use for 2x +-70 ??

Yes you can.

Though I think if you have such questions it's better to explore electronics and basic powersupply rules before constructing an amp. These questions were beginnerlevel only.

wintermute · 12th February 2011, 09:21 PM

The magic number is 1.414. multiply the secondary voltage of the transformer by that and you will get "roughly" the rectified voltage. 50V is the RMS (root mean square) voltage of the transformer, the peak to peak voltage will be 70V.

Note that there are other influences as well. There will actually be a small voltage drop due to the diodes, and when not under full load (depending on transformer regulation) the voltage could be a bit higher.

check out this article by rod elliot for a better understanding

Elliott Sound Products - Linear Power Supply Design

Tony.

dougfunnyBR · 14th February 2011, 12:57 AM

that circuit makes much more sense now..
thanks for all guys !

diy is awesome !!

AndrewT · 14th February 2011, 10:00 AM

A 230:50Vac transformer will over voltage 75Vdc smoothing caps in worst case operational conditions.

12th February 2011, 02:53 PM	#1
dougfunnyBR diyAudio Member Join Date: Jan 2011	Can I Use this Trafo ?? I have a really big 50 - 0 - 50 trafo here with me, but i need +-70 for 2x400w amp... can I use this trafo for +-70 like in this circuit ? sorry for my poor english, i'm brazillian Last edited by dougfunnyBR; 12th February 2011 at 03:05 PM.

12th February 2011, 09:21 PM	#6
wintermute just another diyAudio Moderator Join Date: Aug 2003 Location: Sydney Blog Entries: 22	The magic number is 1.414. multiply the secondary voltage of the transformer by that and you will get "roughly" the rectified voltage. 50V is the RMS (root mean square) voltage of the transformer, the peak to peak voltage will be 70V. Note that there are other influences as well. There will actually be a small voltage drop due to the diodes, and when not under full load (depending on transformer regulation) the voltage could be a bit higher. check out this article by rod elliot for a better understanding Elliott Sound Products - Linear Power Supply Design Tony. __________________ Any intelligence I may appear to have is purely artificial! Some of my photos

14th February 2011, 10:00 AM	#8
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	A 230:50Vac transformer will over voltage 75Vdc smoothing caps in worst case operational conditions. __________________ regards Andrew T.

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12th February 2011, 03:07 PM	#2
dougfunnyBR diyAudio Member Join Date: Jan 2011	[img=http://s1.postimage.org/j6afz5tc4/100503_14mg.jpg]

12th February 2011, 03:13 PM	#3
boyofwax diyAudio Member Join Date: Feb 2004 Location: Arnhem Netherlands	Yes you can use it. If you look at the picture you can see they used the same trafo as you've mentioned.

12th February 2011, 03:20 PM	#4
dougfunnyBR diyAudio Member Join Date: Jan 2011	yeah, but can i use for 2x +-70 ??

14th February 2011, 12:57 AM	#7
dougfunnyBR diyAudio Member Join Date: Jan 2011	that circuit makes much more sense now.. thanks for all guys ! diy is awesome !!

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