hi adrew,yes its 4 ampere core.in EI core there is no. system(4,6,7,8,9,) in india and in toroidal core they are known by ampere rating.we can also judge it by weight.for calculation the true data we need all dimension of core.watts are depend on primary wire rating in all transformer.you can not multiply core ampere into volt for watts.suppose we have 110v instead 220 then 4 *110=440 watts.i will post apmere rating chart of wires.
21swg is 0.52sqmm
@ 3.1A/sqmm that gives a primary rating of ~1.6Aac
multiply by tour mains voltage and you end up around 380VA for the primary.
multiply by transformer efficiency to determine the secondary output and you get a bit more than 360VA, for ~95%
Why are your numbers coming in around 800VA to 1000VA?
Are you using 6A/sqmm for copper current rating?
@ 3.1A/sqmm that gives a primary rating of ~1.6Aac
multiply by tour mains voltage and you end up around 380VA for the primary.
multiply by transformer efficiency to determine the secondary output and you get a bit more than 360VA, for ~95%
Why are your numbers coming in around 800VA to 1000VA?
Are you using 6A/sqmm for copper current rating?
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That is brilliant.
Both in conceiving the idea that a home made tool is possible and in the implementation.
Both in conceiving the idea that a home made tool is possible and in the implementation.
hi adrew,i appreciate all comment and respect all people.i didn't make that toroidal.800va number attach by toroidal manufacturer. i only open and check all data for helping other.but before opening that toroidal i test him i find that it is true 800va.i test him according to my experience.now can you tell us how to check transformer for real va and do you know the power of 21 swg wire? are you professional transformer maker? waiting for your response.
Not a professional electrical person, just an amateur that picks up the kernels worth remembering.
3.1Aac per square millimetre is the usual current rating for transformer wire.
I believe that with the copper price increase over the last decade that many transformer manufacturers are running smaller copper to save money, but this will result in higher regulation and higher heat.
But an increase to about double the 3.1A figure seems far too high.
awg is even smaller than swg.
21swg = 0.5189mm² @ 3.1Aac gives 1.61Aac, but this is not a break figure, just a guide.
21awg = 0.4105mm² @ 3.1Aac gives 1.27Aac
I would expect a good quality transformer rated for 800VA and 96% efficiency to use ~1.17mm² (nearest metric 1.2mm diam), about 18swg = ~16½awg for the primary.
for comparison I looked at an 800VA I have in stock.
The flexible (stranded) primary leadouts are marked as 18awg. I would guess that the primary winding is 1.2mm diam.
The 1000VA is marked the same. This may use a 1.3mm for the primary winding.
3.1Aac per square millimetre is the usual current rating for transformer wire.
I believe that with the copper price increase over the last decade that many transformer manufacturers are running smaller copper to save money, but this will result in higher regulation and higher heat.
But an increase to about double the 3.1A figure seems far too high.
awg is even smaller than swg.
21swg = 0.5189mm² @ 3.1Aac gives 1.61Aac, but this is not a break figure, just a guide.
21awg = 0.4105mm² @ 3.1Aac gives 1.27Aac
I would expect a good quality transformer rated for 800VA and 96% efficiency to use ~1.17mm² (nearest metric 1.2mm diam), about 18swg = ~16½awg for the primary.
for comparison I looked at an 800VA I have in stock.
The flexible (stranded) primary leadouts are marked as 18awg. I would guess that the primary winding is 1.2mm diam.
The 1000VA is marked the same. This may use a 1.3mm for the primary winding.
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Vigortronix Toroidal Transformer 800VA 0 55V 0 55V | Rapid Online
This is a commercial transformer of 800 VA and 55 V. It will say how a commercial company works.
They do 1000 VA also.
If Andrew is an amateur I would give him a job tomorrow if that sort of thing was still in my power. Most accurate man in this forum. Remember also that amateur means someone who loves. Professional means makes money from.
In my shed the largest I have is Nuvotem ( Check ? ) RS0500P1-2-025 . 500 VA 0 -25 0 - 25 10 A. Wire diameter including enamel is 1.92 mm.
http://docs-europe.electrocomponents.com/webdocs/0027/0900766b80027b4a.pdf
This is a commercial transformer of 800 VA and 55 V. It will say how a commercial company works.
They do 1000 VA also.
If Andrew is an amateur I would give him a job tomorrow if that sort of thing was still in my power. Most accurate man in this forum. Remember also that amateur means someone who loves. Professional means makes money from.
In my shed the largest I have is Nuvotem ( Check ? ) RS0500P1-2-025 . 500 VA 0 -25 0 - 25 10 A. Wire diameter including enamel is 1.92 mm.
http://docs-europe.electrocomponents.com/webdocs/0027/0900766b80027b4a.pdf
hi, diy audio fourm need people like you.but sorry for that you cannot use 18swg on that core if you do that then a large amount of heat dispatch from it.
hi, i already told you that you can also judge va power of troroidal by it weight.approx.weight 3.50 kg and power 500va.
Hi Rohin
greetings 8AMPERE CORE PRIMARY 17 SWG SECONDARY 15 SWG
is it ok wire gauge
warm regards
Andrew
greetings 8AMPERE CORE PRIMARY 17 SWG SECONDARY 15 SWG
is it ok wire gauge
warm regards
Andrew
I can instantly see the frustration here. Years ago I could ask the most obscure questions in Google and get answers. Either my questions are getting more difficult or more likely the internet has changed.
E & I transformers can be easily hand made. Toroidals easily machine made. I doubt it would be easy or cheap to buy the toroid parts. The designs are part of a CAD package that can be manipulated for requirements of the customer. For example one might say saturate at 253V ( not always the best choice if 230 V is a realistic voltage ). Nuvotem give data at 253 V.
It is a shame a half toroid couldn't be bought with just the primary. I suspect Tiger in Peterborough if in UK would do it. Tiger are very helpful people. I had a very complicated 250 VA made by then for £35 one off. In tens £30. They certainly did a lot of work. It was cloned to look like old Glasgow ( ? ) company Holden and Fisher ( ? ). That was the choice of my friend. Really nicely made and mm perfect to the gap we had ( 2 mm clearance ).
E&I can often be rebuilt which helps.
Sometimes two smaller toroids cost less. Often they make less noise. Thorens told me two smaller transformers in mechanical anti-phase were very quiet. It might be workable? Two rectifiers. Anyone care to pontificate about out of phase ripple and two bridge rectifiers? I think it is interesting. If I remember it produces more lower harmonics and less higher. That might have been only the one I tried and I might be wrong. If I am right that's a good trade off as lower are almost inaudible. It is 100/120 Hz that we easily hear.
It is better to try and fail. I am 60 and will need 50 years to do some stuff I want to do. Lots with valves and I should say I am not 100 % a valve fanatic.
E & I transformers can be easily hand made. Toroidals easily machine made. I doubt it would be easy or cheap to buy the toroid parts. The designs are part of a CAD package that can be manipulated for requirements of the customer. For example one might say saturate at 253V ( not always the best choice if 230 V is a realistic voltage ). Nuvotem give data at 253 V.
It is a shame a half toroid couldn't be bought with just the primary. I suspect Tiger in Peterborough if in UK would do it. Tiger are very helpful people. I had a very complicated 250 VA made by then for £35 one off. In tens £30. They certainly did a lot of work. It was cloned to look like old Glasgow ( ? ) company Holden and Fisher ( ? ). That was the choice of my friend. Really nicely made and mm perfect to the gap we had ( 2 mm clearance ).
E&I can often be rebuilt which helps.
Sometimes two smaller toroids cost less. Often they make less noise. Thorens told me two smaller transformers in mechanical anti-phase were very quiet. It might be workable? Two rectifiers. Anyone care to pontificate about out of phase ripple and two bridge rectifiers? I think it is interesting. If I remember it produces more lower harmonics and less higher. That might have been only the one I tried and I might be wrong. If I am right that's a good trade off as lower are almost inaudible. It is 100/120 Hz that we easily hear.
It is better to try and fail. I am 60 and will need 50 years to do some stuff I want to do. Lots with valves and I should say I am not 100 % a valve fanatic.
i am 61 and have made a lot of traffos the least 40+ years......
i do not buy them, i build them the way i want to based on what i need...
i salvage them from discarded equipment and rewind/re-purpose
them as my projects required....
i am not a commercial entity, i teach other enthusiasts wind their own..
i am not into the habit of debating with anyone about how to make traffos...
i just build them....
i do not buy them, i build them the way i want to based on what i need...
i salvage them from discarded equipment and rewind/re-purpose
them as my projects required....
i am not a commercial entity, i teach other enthusiasts wind their own..
i am not into the habit of debating with anyone about how to make traffos...
i just build them....
hi adrew,what is core size?there are many size for 8 amp core.but 17 no. swg is not good for that because you will not able to do that in one layer winding.you can use 18no. swg for primary.if you want low volatge in secondary you can use much heavy gauge for that14no. or may be 13no. swg.
In my shed the largest I have is Nuvotem ( Check ? ) P1-2-025 . 500 VA 0 -25 0 - 25 10 A. Wire diameter including enamel is 1.92 mm.
that may be 16no. swg.can handle 10 ampere without any tension.
that may be 16no. swg.can handle 10 ampere without any tension.
It is a competent design and typical. Hope it helps?
I have a lot of work today. I will measure all my smaller ones also as it might help people. All are commercial designs sold by RS or Farnell UK.
I have a lot of work today. I will measure all my smaller ones also as it might help people. All are commercial designs sold by RS or Farnell UK.
My other transformers all have multi strand outputs so of no use. These are added just before the last wrapping added for easy customer soldering .
hi, this is good concept.there are so much idea for toroidal because it has no limit.meaning of no limit is space limitation.you can use any wire gauge on it he will never say you anything.but in EI core your all idea will fail in second.in that condition ,no one give you any idea.then you forget all number 360va or 800va or 1000va.anyhow,four month ago my friend make a transformer for my customer.application is input 110v and output 220v and should be heavy weight.he use 7no. EI core for it which center plate width is 5.1 cm and 3.50inch length.for 110v , 17.50 swg turn 160 + 16 no. swg turn 160.first lead of primary common and then joint of both no. which is input and last lead is output.he is taking 12 ampere input current regular for 24 hour. no complaint.but so much heat you cann't put hand on it.but working.thats all for me.but i didn't advice him that he may use much that specific gauge because i know ampere capacity of wires.i only concern about work and profit. if my customer happy then there is no mean.
800VA LU@IN@S INVERTVER TRANSFORMER DATA
core size= no.4 in EI core(center plate width is 3.8cm)
length=8cm
core material=c2
primary no.=20.5swg,turn=1 to 215 to 355(after 215 turn there is loop for charging)
secodary no.=12 swg,turn= 16-0-16
core size= no.4 in EI core(center plate width is 3.8cm)
length=8cm
core material=c2
primary no.=20.5swg,turn=1 to 215 to 355(after 215 turn there is loop for charging)
secodary no.=12 swg,turn= 16-0-16
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