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Can't find the transformer I need so need to build my own

brandnewb

Nov 30, 2021
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if anything I can take the inner parts and use it to step up and down from if needed. but then at least the source will be well thought of, not something I am doing at the moment
 

brandnewb

Nov 30, 2021
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And then again gang, do not we all need a good mains transformer? I mean why is this not something a standard hanging in our mains breaker panel to begin with?
 

brandnewb

Nov 30, 2021
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and let me also state that I am willing to take things very slowly as to not endanger my self or anyone around the contraption I am making.

Let's take this project a bit more serous/

How does one do it while staying safe?
 

brandnewb

Nov 30, 2021
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ok, let me then start with the oversizing aspect.

rather than calculating, which can be dificult for many of us, certainly me, how about we simply make the core huge?

But then again the questions remains, how to source the correct core material?

As far as I understood it at low frequencies as below 4000 Hz an iron core still applies, however one of us in this thread suggested otherwise.

Unless I stand corrected I think a ferrtite core comes into play at 4000 Hz and above and for anything lower like a house hold frequency then an iron core still could be applicable.
 

Harald Kapp

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Nov 17, 2011
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Here is a complete tutorial on transformer construction (multiple pages, link list at the end of each page).
The "iron" core is not made from any random metal sheet you may find in a scrapyard. To build a good transformer requires high quality special steel with select magnetic properties and well defined mechanical contours (e.g. to achieve a defined magnetic gap).
For high power application losses can be minimized by using a toroidal transformer.
The size of the core you need depends on many factors, such as power, wire size, isolation voltage, frequency etc.

Building your own core is not easy - whereas it is easy to make mistakes while doing so. Better get a ready-to-use core.
 

kellys_eye

Jun 25, 2010
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Let's take this project a bit more serous/

You first.

You have yet to put a practical application forward and ignore advice already given on designing transformers and/or using commercially available items never mind the actual reason you seem to want to keep pushing the 'solution'.

1. You don't need to charge the batteries at 1C to prove their worth.
2. You can't charge them directly from a transformer anyway (you need DC, not AC)
3. Assuming you got the right transformer you have to design/build the rectification, smoothing and regulation (as well as current limitation)
4. You have little comprehension of the scale and dangers involved
5. We're constantly having to repeat ourselves as you don't seem to acknowledge the information already given

If you want to be 'serious' about this then stop trolling us.
 

brandnewb

Nov 30, 2021
75
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You first.

You have yet to put a practical application forward and ignore advice already given on designing transformers and/or using commercially available items never mind the actual reason you seem to want to keep pushing the 'solution'.

1. You don't need to charge the batteries at 1C to prove their worth.
2. You can't charge them directly from a transformer anyway (you need DC, not AC)
3. Assuming you got the right transformer you have to design/build the rectification, smoothing and regulation (as well as current limitation)
4. You have little comprehension of the scale and dangers involved
5. We're constantly having to repeat ourselves as you don't seem to acknowledge the information already given

If you want to be 'serious' about this then stop trolling us.
I am dead serious and am not a troll. I hope you guys will learn that along the way.

I'll answer your questions.
1. noted, but I am aiming at .5C
2. understood. using a full bridge rectifier or similar would be a later step in the design.
3. I am going to use a 3 phase source to help with smoothening the ripple.
4 Agreed.
5. I am not sure that's true. I feel like I am being steered of off this path and am aware of the good intentions behind it. So no disrespect meant but I'd like to continue on this path.

Once again, no disrespect meant and I hope everyone can give me a bit more time to prove I am not a troll.

Anyway I have a status update.
After many iterations I am now able to get 230VAC through the primary coil and get something out of the secondary.

upload_2022-3-26_15-9-53.png

going into the variac is 8.26 amps. going out of the variac into the primary coili 1 amp. Coming out of the secondary coil is 6.23VAC.

The core (the pvc pipe) is fully filled with iron powder.

The next step I think would be to make sure that the amps in the secondary coild will never exceed 140 amps (.5C).

Would anyone have a suggestion on how to do that?
 
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