How do wind a transformer - Electronic Circuits Projects Diagrams Free

FusionITR · 17th May 2006, 07:34 AM

Does anybody have a site that explains (preferably with diagrams/pictures) how to wind a transformer? Possibly with more that one type of core (E-E prefered).

I dont need to know how to design a transformer, just want a tutorial on proper winding techniques.

ZIGGY_DAN · 17th May 2006, 11:19 AM

here is one of my home made transformers, i took the core from an old knakked one. It has a turn ratio of some thing like 200:1, i used it to step 12V up to about 2,400V. the plastic you can see started life as square PVC drainpipe, i shaped it with the heat from a soldering iron. the wire guage on the outside is #18SWG and internal is #32SWG. i wound it with a drill, another method is to wind the primary on the bottom half of the core and the secondary on the top. this transformer does not work as i killed it with overvoltage, was pretty funny though.

below are some links
http://www.geofex.com/Article_Folder...es/xformer.htm
http://www.obsoleteelectronics.com/T...ansformers.htm

hope this helps?

FusionITR · 17th May 2006, 07:21 PM

Also, is there a website similar to digikey that sells ferrite cores, bobbin, wires, and other custom transformer accessories? I want to order some magnetics inc materials but it looks like their only distrubors only sell for large scale distrubition. All I want to do is order about 5-10 cores, bobbins, and wires.

FusionITR · 18th May 2006, 04:57 AM

A little help?

chemelec · 18th May 2006, 01:05 PM

There can be a Big Difference between winding EI Cores, Verses Ferrites, Verses Torroids.

What Exactially are you Trying to make?

Dexter Magnetics Sells Ferrites and there Minimum order is only $50.00.

But they do Not sell Wire or EI Laminates.

If you can give me More Specific Info, Possibly I can help you better.

FusionITR · 19th May 2006, 05:44 AM

A $50 minimum is fine. I just didnt want to order from a distubuter wanting minimum orders of $1000 or something aimed at mass selling to businesses.

I'm trying to make a high frequency transformer for a SMPS. I still need to learn a bit about how to wind a transformer, so I will probably be ordering a few E and I cores to play with along with some wire, laminates, tape, and bobbin.

Any info on where I can aquire some of these would be appretiated.

chemelec · 19th May 2006, 01:03 PM

Quote:

Originally Posted by FusionITR

A $50 minimum is fine. I just didnt want to order from a distubuter wanting minimum orders of $1000 or something aimed at mass selling to businesses.

I'm trying to make a high frequency transformer for a SMPS. I still need to learn a bit about how to wind a transformer, so I will probably be ordering a few E and I cores to play with along with some wire, laminates, tape, and bobbin.

Any info on where I can aquire some of these would be appretiated.

Before you try to buy any cores you better read up on Magnetics and Ferrite transformers.

Dexter Magnetics is a Good Supplier of various ferrites from various manufacturers. (Fair-Rite, Philips, Magnetics, and many more) They just sell the Ferrites and Bobbins. NO Wire.
1-800-775-3829

If your trying to build a high power, high frequency unit, I would recommend a Fair-Rite E-core, using Material 77.
You Need to also Understand "AL" Values and how to Properly Gap the Ferrites.
There is an article on "AL Value Calculations" on my Website.

Additionally, if you plan to have a DC Output, Remember that High Frequency Requires Special Diodes.

Also, Depending on What you want? I can possibly also supply some Ferrites, as well as wire. But you need to email me direct, with some more Specific info of What you are trying to make. (Current Requirement, Voltages involved, Frequency, etc.)

Gary

moody07747 · 19th May 2006, 03:50 PM

Quote:

Originally Posted by ZIGGY_DAN

here is one of my home made transformers, i took the core from an old knakked one. It has a turn ratio of some thing like 200:1, i used it to step 12V up to about 2,400V. the plastic you can see started life as square PVC drainpipe, i shaped it with the heat from a soldering iron. the wire guage on the outside is #18SWG and internal is #32SWG. i wound it with a drill, another method is to wind the primary on the bottom half of the core and the secondary on the top. this transformer does not work as i killed it with overvoltage, was pretty funny though.

below are some links
http://www.geofex.com/Article_Folder...es/xformer.htm
http://www.obsoleteelectronics.com/T...ansformers.htm

hope this helps?

and heres one of mine...well...3

http://s2.photobucket.com/albums/y22...ewwindings.jpg
http://s2.photobucket.com/albums/y22...mallbusbar.jpg
http://s2.photobucket.com/albums/y22...ent=Under5.jpg
http://s2.photobucket.com/albums/y22...ishedSmall.jpg

those pics are not the best as they were taken with my old cam...a Kodak MC3

2 with about 50 turns of 12 gauge wire...solid, and the other side is left untouched with what looks to be 14 or 16 wire

just used chiseled off one side of the secondary and after it looked like a "C" from the top view I used a wood punch to hammer the wire out of the slots

I was always told it was better to keep a trans. closed up...even when working on it as after opening high current ones, its hard to keep them from buzzing and heating up allot.....on top of that its just hard grinding out a weld then putting the trans back together

BTW those transformers in the stick welder put out about 80V and 90A

Jack Luminous · 19th May 2006, 05:52 PM

On a related note, Nuts & Volts magazine published plans for a coil winder project recently you might be interested in tracking down.
Looks like a zip file of the plans can be found here: http://www.nutsvolts.com/toc_Pages/jun05toc.htm

FusionITR · 19th May 2006, 11:16 PM

Quote:

Originally Posted by chemelec

snip

Just to let you know I sent you an email.

Rexx99 · 15th March 2008, 07:40 AM

hi there,

Can i ask something about the transformer...?

1. Do you know about the transformer use in the common mobile phone charger? It is a step down transformer right?So here i want to ask, can i modified the transformer so that it can be a STEP UP TRANSFORMER?

2. Lets say the step down transformer in the mobile phone charger step down 240V to 5V, can it be reversed back so that it can step up from 5V to 240V back? Will it possible?

Please help me.
thats all.

**Nigel Goodwin** · 15th March 2008, 10:06 AM

Assuming it's a conventional transformer (and not a switch-mode power supply - but most are), then you can input 5V AC to the secondary, and get 240V AC out of the primary.

But even assuming it's a conventional transformer, you would have to remove it from the chager, as the charger will have a rectifer inside, which will stop it working.

But notice you require an AC power source, not a DC one.

Hero999 · 18th March 2008, 10:52 PM

One word of warning, don't expect to be able to connect 5VAC to the secondary of a 240V to 5VAC transformer and get 240VAC. In practice you'll get something closer to 210V which will drop down to 180V with a load connected. Transfromers aren't perfect and there will be losses, especially if it's a small transformer.

My advice is to measure the off load voltage, then connect it up to a voltage source of the same value and the loaded secondary voltage should be pretty close to the mains voltage it's designed to run off.

I've rewound a mains transformer before. I got it from a training centre I used to go to. It was an RS 100VA tranformer kit that had already been assembled and wound to give 19V unloaded. This was no good for me so I decided to turn it into an isolation transformer. I worked out the number of volts per turn by unwinding it can counting the number of turns and dividing the measured voltage by the number of turns.

When I rewound it I increased the number of turns by about 15% in the knowledge that the voltage will drop when a load is connected. After winding 1200 or so turns I connected the mains to the primary and measured the secondary voltage. With 230V on the primary, the secondary measured about 250V, I connected a 100W light bulb to the secondary and the voltage dropped to just below the input voltage. I tried connecting the secondary to the mains and the primary voltage was about 210V - I didn't bother connecting any loads as this isn't of any use to me.

mooredan · 25th March 2008, 04:30 AM

I'm set to wind a transformer for the very first time and would welcome any pointers, gotcha's, etc.

ETD34 core
primary: 12T, center tap, #18AWG
secondary: 275T, #24AWG

I have a few "elementary" questions:

Is there an easy way to count the 275 turns? ...does anyone have a makeshift apparatus to help with this?
How to do the center tap? I've read two ways to do it: 1) double over the wire and wind and then join one starting end with the other finishing end 2) "dimple" the wire half way and solder in the center tap
Which gets wound first? ...the long secondary or the short primary?
How important is neatness? ...can the coils of one row "cross over" each other?

Thanks.
Dan

RODALCO · 25th March 2008, 06:32 PM

I use a meccano winder with an old counter from a gas meter to count the turns.

Neatness is important to keep minimum voltage difference between turns. a layer of insulating material between layers of windings is good practise although it makes the transformer coil bigger.

Usually the secondary is closesd to the iron yoke.

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17th May 2006, 07:34 AM	(permalink)
FusionITR	How do wind a transformer Does anybody have a site that explains (preferably with diagrams/pictures) how to wind a transformer? Possibly with more that one type of core (E-E prefered). I dont need to know how to design a transformer, just want a tutorial on proper winding techniques.

17th May 2006, 07:21 PM	(permalink)
FusionITR	Also, is there a website similar to digikey that sells ferrite cores, bobbin, wires, and other custom transformer accessories? I want to order some magnetics inc materials but it looks like their only distrubors only sell for large scale distrubition. All I want to do is order about 5-10 cores, bobbins, and wires.

18th May 2006, 04:57 AM	(permalink)
FusionITR	A little help?

18th May 2006, 01:05 PM	(permalink)
chemelec	There can be a Big Difference between winding EI Cores, Verses Ferrites, Verses Torroids. What Exactially are you Trying to make? Dexter Magnetics Sells Ferrites and there Minimum order is only $50.00. But they do Not sell Wire or EI Laminates. If you can give me More Specific Info, Possibly I can help you better. __________________ I No Longer accept Private Messages on here. All Emails to me Must Contain the Word \"Electronic\" in the \"Subject Line\" or they go Directly to my Junk Mail Folder. Email me at: chemelec@hotmail.com Website: http://www3.telus.net/chemelec

19th May 2006, 05:44 AM	(permalink)
FusionITR	A $50 minimum is fine. I just didnt want to order from a distubuter wanting minimum orders of $1000 or something aimed at mass selling to businesses. I'm trying to make a high frequency transformer for a SMPS. I still need to learn a bit about how to wind a transformer, so I will probably be ordering a few E and I cores to play with along with some wire, laminates, tape, and bobbin. Any info on where I can aquire some of these would be appretiated.

19th May 2006, 05:52 PM	(permalink)
Jack Luminous	On a related note, Nuts & Volts magazine published plans for a coil winder project recently you might be interested in tracking down. Looks like a zip file of the plans can be found here: http://www.nutsvolts.com/toc_Pages/jun05toc.htm

15th March 2008, 07:40 AM	(permalink)
Rexx99	hi there, Can i ask something about the transformer...? 1. Do you know about the transformer use in the common mobile phone charger? It is a step down transformer right?So here i want to ask, can i modified the transformer so that it can be a STEP UP TRANSFORMER? 2. Lets say the step down transformer in the mobile phone charger step down 240V to 5V, can it be reversed back so that it can step up from 5V to 240V back? Will it possible? Please help me. thats all.

15th March 2008, 10:06 AM	(permalink)
Nigel Goodwin	Assuming it's a conventional transformer (and not a switch-mode power supply - but most are), then you can input 5V AC to the secondary, and get 240V AC out of the primary. But even assuming it's a conventional transformer, you would have to remove it from the chager, as the charger will have a rectifer inside, which will stop it working. But notice you require an AC power source, not a DC one. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

18th March 2008, 10:52 PM	(permalink)
Hero999	One word of warning, don't expect to be able to connect 5VAC to the secondary of a 240V to 5VAC transformer and get 240VAC. In practice you'll get something closer to 210V which will drop down to 180V with a load connected. Transfromers aren't perfect and there will be losses, especially if it's a small transformer. My advice is to measure the off load voltage, then connect it up to a voltage source of the same value and the loaded secondary voltage should be pretty close to the mains voltage it's designed to run off. I've rewound a mains transformer before. I got it from a training centre I used to go to. It was an RS 100VA tranformer kit that had already been assembled and wound to give 19V unloaded. This was no good for me so I decided to turn it into an isolation transformer. I worked out the number of volts per turn by unwinding it can counting the number of turns and dividing the measured voltage by the number of turns. When I rewound it I increased the number of turns by about 15% in the knowledge that the voltage will drop when a load is connected. After winding 1200 or so turns I connected the mains to the primary and measured the secondary voltage. With 230V on the primary, the secondary measured about 250V, I connected a 100W light bulb to the secondary and the voltage dropped to just below the input voltage. I tried connecting the secondary to the mains and the primary voltage was about 210V - I didn't bother connecting any loads as this isn't of any use to me. __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez

25th March 2008, 04:30 AM	(permalink)
mooredan	Another noobie winding a transformer I'm set to wind a transformer for the very first time and would welcome any pointers, gotcha's, etc. ETD34 core primary: 12T, center tap, #18AWG secondary: 275T, #24AWG I have a few "elementary" questions: Is there an easy way to count the 275 turns? ...does anyone have a makeshift apparatus to help with this? How to do the center tap? I've read two ways to do it: 1) double over the wire and wind and then join one starting end with the other finishing end 2) "dimple" the wire half way and solder in the center tap Which gets wound first? ...the long secondary or the short primary? How important is neatness? ...can the coils of one row "cross over" each other? Thanks. Dan

25th March 2008, 06:32 PM	(permalink)
RODALCO	I use a meccano winder with an old counter from a gas meter to count the turns. Neatness is important to keep minimum voltage difference between turns. a layer of insulating material between layers of windings is good practise although it makes the transformer coil bigger. Usually the secondary is closesd to the iron yoke. __________________ There are more ways to get to Rome. Electricity, Electric clocks, Meters and Trains are great.