360VA Toroid

hawkfeather · 3rd February 2006, 01:36 PM

Anyone have some winding instructions or tips for toroidal transformers? I want to get 55V DC out of one for a 100W mono board.

lineup · 3rd February 2006, 02:09 PM

Theory of how to wind toroid transformers.

Size and material of core
Wire dimensions
Number of primary turns
Number of secondary turns
Fixation of the windings

Aside from getting it all right,
I do not think you have much money to gain from wind your own trafos.
How come you think of doing it, instead of buying?

hawkfeather · 3rd February 2006, 03:11 PM

Well... I guess I love a challenge, and I'm a little hardheaded. I guess I'm thinking DIY all the way? LOL I s it really that difficult?

AndrewT · 3rd February 2006, 04:24 PM

Hi,
start with a pre-wound primary. It should be tested as well.

DIY allows you extra windings exactly matching your requirements.

If a standard pair are good enough then then buy ready made even secondhand, eBay is a good source.

360VA will allow about 180 to 260 Watts of amplifier output. Translated into two channels this equates to 90W+90W upto 130W+130W of continuous power.

There are a number of sites giving winding info and some previous threads here on DIYaudio.

croat47 · 3rd February 2006, 04:24 PM

Try:

www.toroid.com. There is a bit of theory on the Kits page. Notice the "Kits" page. They give you what you need, except for magnet wire.

I am looking to build an integrated amp, and the custom aspect of winding your own is appealing for that.

Also, I did find a site that had all the calcs you need for transformer design...I'll look for it again...

hawkfeather · 3rd February 2006, 04:54 PM

Hey Croat..

That calculator site address would probably help me a lot. Thanx for looking... I already ordered a "kit" last week of toroid.coms 80VA kit just so I could teach myself how to wind them!

lineup · 3rd February 2006, 05:07 PM

Here is a topic about

winding toroidal power transformer

hawkfeather · 3rd February 2006, 05:21 PM

How about the 200VA per side. How many watts, amps, and volts would that give me for one channel?

AndrewT · 3rd February 2006, 05:38 PM

Hi,
as a rule of thumb, divide the VA by 1.5 to give the maximum power output. 200VA > about 130W.
Decide on the minimum load impedance you want this power to drive. Vpk=sqr rt(P*R*2). Add on some Vrail to Voutput loss, say 6Volts, giving a Vrail = +-(Vpk+6).
Vac = Vrail/1.414

For an 8ohm load then Vac=36Vac to 37Vac.
The unloaded Vrail will be about 8% higher than loaded Vrail and at peak mains incoming voltage you should allow about +6% again or a higher figure if you know the tolerance from your supply company.
This max peak value determines the working voltage of your smoothing caps (63Vdc).

croat47 · 3rd February 2006, 05:56 PM

Here are some I found that may be useful.

I was thinking of this one as it shows calcs based on what type of filtering, rectification, and transformer you are using.

http://www.atc-frost.com/products/design/va.htm

Step by Step:

http://www.geofex.com/Article_Folder...es/xformer.htm

3rd February 2006, 01:36 PM	#1
hawkfeather diyAudio Member Join Date: Dec 2005 Location: PA	360VA Toroid Anyone have some winding instructions or tips for toroidal transformers? I want to get 55V DC out of one for a 100W mono board. __________________ Is it not better to burn out, than to fade away?

3rd February 2006, 02:09 PM	#2
lineup diyAudio Member Join Date: Dec 2005 Location: the north	Theory of how to wind toroid transformers. Size and material of core Wire dimensions Number of primary turns Number of secondary turns Fixation of the windings Aside from getting it all right, I do not think you have much money to gain from wind your own trafos. How come you think of doing it, instead of buying? __________________ lineup

3rd February 2006, 03:11 PM	#3
hawkfeather diyAudio Member Join Date: Dec 2005 Location: PA	Why? Well... I guess I love a challenge, and I'm a little hardheaded. I guess I'm thinking DIY all the way? LOL I s it really that difficult? __________________ Is it not better to burn out, than to fade away?

3rd February 2006, 04:54 PM	#6
hawkfeather diyAudio Member Join Date: Dec 2005 Location: PA	Good deal. Hey Croat.. That calculator site address would probably help me a lot. Thanx for looking... I already ordered a "kit" last week of toroid.coms 80VA kit just so I could teach myself how to wind them! __________________ Is it not better to burn out, than to fade away?

3rd February 2006, 05:07 PM	#7
lineup diyAudio Member Join Date: Dec 2005 Location: the north	Here is a topic about winding toroidal power transformer __________________ lineup


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3rd February 2006, 04:24 PM	#4
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, start with a pre-wound primary. It should be tested as well. DIY allows you extra windings exactly matching your requirements. If a standard pair are good enough then then buy ready made even secondhand, eBay is a good source. 360VA will allow about 180 to 260 Watts of amplifier output. Translated into two channels this equates to 90W+90W upto 130W+130W of continuous power. There are a number of sites giving winding info and some previous threads here on DIYaudio.

3rd February 2006, 04:24 PM	#5
croat47 diyAudio Member Join Date: May 2005 Location: Eastern Shore, Maryland	Try: www.toroid.com. There is a bit of theory on the Kits page. Notice the "Kits" page. They give you what you need, except for magnet wire. I am looking to build an integrated amp, and the custom aspect of winding your own is appealing for that. Also, I did find a site that had all the calcs you need for transformer design...I'll look for it again...

3rd February 2006, 05:21 PM	#8
hawkfeather diyAudio Member Join Date: Dec 2005 Location: PA	200VA How about the 200VA per side. How many watts, amps, and volts would that give me for one channel? __________________ Is it not better to burn out, than to fade away?

3rd February 2006, 05:38 PM	#9
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, as a rule of thumb, divide the VA by 1.5 to give the maximum power output. 200VA > about 130W. Decide on the minimum load impedance you want this power to drive. Vpk=sqr rt(PR2). Add on some Vrail to Voutput loss, say 6Volts, giving a Vrail = +-(Vpk+6). Vac = Vrail/1.414 For an 8ohm load then Vac=36Vac to 37Vac. The unloaded Vrail will be about 8% higher than loaded Vrail and at peak mains incoming voltage you should allow about +6% again or a higher figure if you know the tolerance from your supply company. This max peak value determines the working voltage of your smoothing caps (63Vdc).

3rd February 2006, 05:56 PM	#10
croat47 diyAudio Member Join Date: May 2005 Location: Eastern Shore, Maryland	Links to Calcs... Here are some I found that may be useful. I was thinking of this one as it shows calcs based on what type of filtering, rectification, and transformer you are using. http://www.atc-frost.com/products/design/va.htm Step by Step: http://www.geofex.com/Article_Folder...es/xformer.htm

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