Help with transformers

BIA · 31st December 2012, 08:53 PM

Hi im new , i need help .

I have transformer its 240vac , the secondary winding is 0-24vac .

Do i use a Bridge rectifier to get +/- V dc or do i use two diodes ?

Im totally stumped . ;-/

bear · 31st December 2012, 09:20 PM

Yes.

Look up online

"Full Wave Rectifier"

and

"Bridge Rectifier"

You will not be able to get + & - from a single secondary.

There are tricks to get a "center" point, but that's not probably something you want to do. Are you sure you have ONLY a single secondary??

Two wires? Or Three? Or four?

BIA · 31st December 2012, 09:33 PM

Two wires , 0-21vac

BIA · 31st December 2012, 09:51 PM

Hi yes i dont know what you mean by single secondary , all i know is the transformer has an output of 0-21vac , so the Alternating current is bouncing/pulsing along the ground never going negative volts .

So how do i split this into +/- dc ?

paulb · 31st December 2012, 10:28 PM

Elliott Sound Products - Linear Power Supply Design
I suggest that you read the entire article.

sawreyrw · 31st December 2012, 10:33 PM

You should use two diodes to form two half wave recifiers. Of course, you need properly sized diodes and caps.

nigelwright7557 · 11:02 PM

Quote:

Originally Posted by bear

Yes.

You will not be able to get + & - from a single secondary.

There are tricks to get a "center" point, but that's not probably something you want to do. Are you sure you have ONLY a single secondary??

Two wires? Or Three? Or four?

You can get two rails from a single transformer using half wave rectification to get each supply.
I know the picture shows two windings but treat as one for your purpose.

CharlieLaub · 1st January 2013, 12:08 AM

I believe that Nigel meant to show an earth ground connected to the "ZEROVOLTS" output. If this is not included, I believe that the whole PS can/will float...

-Charlie

bear · 1st January 2013, 01:49 AM

Get yourself another identical transformer.

Or

Get yourself a proper transformer for the job (which you did not say what it is). Imo half wave rectifier supplies are not normally a great idea...

You might say what your application is, so that folks might give you a better bit of input?

paulb · 1st January 2013, 02:06 AM

Quote:

Originally Posted by bear

Imo half wave rectifier supplies are not normally a great idea...

Why? Because you need twice the capacitance?

31st December 2012, 08:53 PM	#1
BIA diyAudio Member Join Date: Jan 2011	Help with transformers Hi im new , i need help . I have transformer its 240vac , the secondary winding is 0-24vac . Do i use a Bridge rectifier to get +/- V dc or do i use two diodes ? Im totally stumped . ;-/

31st December 2012, 09:20 PM	#2
bear expert in tautology diyAudio Member Join Date: Apr 2002 Location: New York State USA	Yes. Look up online "Full Wave Rectifier" and "Bridge Rectifier" You will not be able to get + & - from a single secondary. There are tricks to get a "center" point, but that's not probably something you want to do. Are you sure you have ONLY a single secondary?? Two wires? Or Three? Or four? __________________ _-_-bear http://www.bearlabs.com [...2SJ74 Toshiba bogus asian parts - beware! ] -- Btw, I don't actually know anything, FYI --

31st December 2012, 09:51 PM	#4
BIA diyAudio Member Join Date: Jan 2011	Transformer Help Hi yes i dont know what you mean by single secondary , all i know is the transformer has an output of 0-21vac , so the Alternating current is bouncing/pulsing along the ground never going negative volts . So how do i split this into +/- dc ?

1st January 2013, 01:49 AM	#9
bear expert in tautology diyAudio Member Join Date: Apr 2002 Location: New York State USA	Get yourself another identical transformer. Or Get yourself a proper transformer for the job (which you did not say what it is). Imo half wave rectifier supplies are not normally a great idea... You might say what your application is, so that folks might give you a better bit of input? __________________ _-_-bear http://www.bearlabs.com [...2SJ74 Toshiba bogus asian parts - beware! ] -- Btw, I don't actually know anything, FYI --

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

31st December 2012, 09:33 PM	#3
BIA diyAudio Member Join Date: Jan 2011	Two wires , 0-21vac

31st December 2012, 10:28 PM	#5
paulb diyAudio Member Join Date: Jun 2001 Location: Calgary	Elliott Sound Products - Linear Power Supply Design I suggest that you read the entire article.

31st December 2012, 10:33 PM	#6
sawreyrw diyAudio Member Join Date: Apr 2006 Location: Minnesota	You should use two diodes to form two half wave recifiers. Of course, you need properly sized diodes and caps.

1st January 2013, 12:08 AM	#8
CharlieLaub diyAudio Member Join Date: Mar 2007 Location: California	I believe that Nigel meant to show an earth ground connected to the "ZEROVOLTS" output. If this is not included, I believe that the whole PS can/will float... -Charlie

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Making CT transformers from two transformers	infernal	Parts	1	14th July 2011 08:42 AM
transformers	JozzaG	Power Supplies	0	4th February 2010 08:57 PM
Help identifying a pair of output transformers and power transformers	mjk130	Parts	3	30th January 2009 10:44 AM
Back to Back transformers as Isolation transformers	mikee55	Chip Amps	2	17th March 2006 11:38 AM
Why Transformers?	guitargully	Everything Else	3	16th April 2004 06:19 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read