hi
i want to build my own toroid transformer and need some helps
which core material should i use?
i need calculation formulas and winding techniques
is there any good source for design toroid transformer?
i want to build my own toroid transformer and need some helps
which core material should i use?
i need calculation formulas and winding techniques
is there any good source for design toroid transformer?
There are also transformer companies that will do one-offs for a price. You give them the electrical specs you want and the physical size restraints you have, and you end up with a known good replacement. I have a Marantz 8B tube power amp that had a power transformer failure, and the replacement I ordered worked like a charm.
How many do you intend to build?
You will need to build or buy a toroid winding machine. ($$$$$)
toroidal winding machine -toroidal winder -current transformer winding machine winding machine - YouTube
Do you have a local (inside Iran) transformer components supplier? Cores, wire, insulating sheet and tape, mounting hardware.
Transformer material is *heavy* so if you have to import, shipping will double or triple purchase cost, plus any Customs fees and tax.
My point being that for a couple units, buying ready made, even if custom made, is cheaper, faster and more practical.
Now if you want to start a toroid winding shop, go for it, but you´ll have to invest some money, learn and get suppliers.
audio amplifire
no need to winding machine i do it by hands.
i have experience winding smps toroid transformers like PFC/output inductors/....
there is many kind of ferrite and powder core in my country and i just don't know which core material should i use and a little information about formulas and winding tips if there is
there is no ready made here to buy.
i found the solution
the material of these trnsformers core is silicon-steel which has two kind:grain-oriented and non grain-oriented
i found a 400VA core for 4 dollars.
calculation is simple like regular E-I transformer
order some copper wire for 3 dollars and now should wind the transformer
finally it costs about 9 dollars.
the material of these trnsformers core is silicon-steel which has two kind:grain-oriented and non grain-oriented
i found a 400VA core for 4 dollars.
calculation is simple like regular E-I transformer
order some copper wire for 3 dollars and now should wind the transformer
finally it costs about 9 dollars.
"i found a 400VA core for 4 dollars.
calculation is simple like regular E-I transformer
order some copper wire for 3 dollars and now should wind the transformer
finally it costs about 9 dollars"
I am not sure where you are getting these prices from, but the core for the transformer should be much more and the magnet wire not "copper wire" is actually expensive .But good luck to you.
calculation is simple like regular E-I transformer
order some copper wire for 3 dollars and now should wind the transformer
finally it costs about 9 dollars"
I am not sure where you are getting these prices from, but the core for the transformer should be much more and the magnet wire not "copper wire" is actually expensive .But good luck to you.
A 400 VA core takes about 2.25 turns per volt. $3 worth of magnet wire won’t go very far. Remember in transformer application, you have to derate wire capacity by half compared to what you would normally do - eg, 18 ga wire is good for 5 amps not the usual 10. Unless you want your transformer to run really HOT.
yes in normal situation a current density of 4-6 A/mm2 is good but i take it about 2.5 A/mm2 in my transformer.i think it's good
calculation is very simple just need these formula: V=4.44NFBA and VA=V*A !!!
the core is a used core so price is less than a new one and 4 dollars isn't so weird.
my transformer needs about 0.65 grams magnet wire and it costs about 3.5 dollars.(in my country)
also needs some insulating tape/heat shrink/copper shielding foil/adhesive
and all of these costs maximum 10 dollars.
i don't know where is weird?!
i will post transformer pics soon.
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You mean 0.65 KILO grams ?
Ferrite and powder core wires are for very high frequency and take few turns, easy to hand wind; but for 50Hz mains your hands will get very tired 🙂
Yes, you can hand wind, it just will take a lot of patience.
We are not against you, quite the contrary, we are HAPPY to help, just want you to be realistic 😉
Just some mental calculations:
A 400VA core will have about 20 square centimeters section.
N0 (N sub zero) , turns per *one* Volt, for 50Hz and standard silicon steel, will be 45/S (S= area/section) so for 220V mains:
N0=(45/20)*220=495 turns.
Add 5% (rule of thumb) to compensate for core idle magnetization losses and you will end with a 520 turn primary.
Doable by hand, but certainly tiring.
Same winding on an EI core is much easier because you can mount the plastic bobbin on a wooden core and hand turn it, one hand turns the handle, the other guides the wire; but "hand knitting" wire on a toroid core is slow and tiring.
Ok, it´s your time and hands 🙂
Primary current will be about 2A so you will need 1mm diameter wire for current density 2.5A/mm^2
Don´t know your needed secondary voltage or current .
EDIT: if you get a used transformer (they must have pulled the used core from one of those) you can save A LOT of work, by rewinding your custom secondary but reusing he primary.
Ferrite and powder core wires are for very high frequency and take few turns, easy to hand wind; but for 50Hz mains your hands will get very tired 🙂
Yes, you can hand wind, it just will take a lot of patience.
We are not against you, quite the contrary, we are HAPPY to help, just want you to be realistic 😉
Just some mental calculations:
A 400VA core will have about 20 square centimeters section.
N0 (N sub zero) , turns per *one* Volt, for 50Hz and standard silicon steel, will be 45/S (S= area/section) so for 220V mains:
N0=(45/20)*220=495 turns.
Add 5% (rule of thumb) to compensate for core idle magnetization losses and you will end with a 520 turn primary.
Doable by hand, but certainly tiring.
Same winding on an EI core is much easier because you can mount the plastic bobbin on a wooden core and hand turn it, one hand turns the handle, the other guides the wire; but "hand knitting" wire on a toroid core is slow and tiring.
Ok, it´s your time and hands 🙂
Primary current will be about 2A so you will need 1mm diameter wire for current density 2.5A/mm^2
Don´t know your needed secondary voltage or current .
EDIT: if you get a used transformer (they must have pulled the used core from one of those) you can save A LOT of work, by rewinding your custom secondary but reusing he primary.
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i'm realastic and maybe prices in my country are lower especially used things.
sorry yes 0.65 kilograms
i wound a lot of flyback transformer which have primary turns above 200 so winding is not problem for me and i love it!
i change the core to a 200VA because of some reason.
about core power rating why you all guys calculate core power by section area?!
as we know this transformer follow this formula:
V=4.44NFBA so B=V/4.44NFA (your 45 number in your formula come from this eqation.i can explain)
B is constant since V & F & N & A are constant which they are
so magnetic field is constant and indipendent of primary current.power is V*A and V is constant at around 220V so current is the paramater which change the power rating.we can rise the current for higher level of power but problem is wire thickness which at higher current produce more losses and generate heat that may cause serious problems but we can use thicker wire in primary side(in secondary at same time if needed) to solve this problem but insofar as fitting them and leakage magnetic not be a problem.
so we can use for example a 200VA core at higher power rating like 250-300VA due to output current and voltage
am i right?
another question is about VA
for example assume a 200VA core . this 200 is AC power or DC ?after rectifying and convert AC to DC we can have about 1.41*200=282 watts DC power.is that right?