hi tony,
my bad luck, i saw winding machine in one shop as same as yours last month,
but last week when i go to buy it was finished,
so waiting for the machine.
from youtube: take note that he used a higher flux density, he must be using good quality cores...
Build a transformer (DIY) - YouTube
Build a transformer (DIY) - YouTube
hi tony,
with 1,1/2 inch center leg, can i get 2000watt transformer 60,30,0,30,60v ac?
with 1,1/2 inch center leg, can i get 2000watt transformer 84,42,0,42,84v ac?
with 1,1/2 inch center leg, can i get 2000watt transformer 90,45,0,45,90v ac?
if yes, can u pls tell the specs for these transformers.
thank u.
with 1,1/2 inch center leg, can i get 2000watt transformer 60,30,0,30,60v ac?
with 1,1/2 inch center leg, can i get 2000watt transformer 84,42,0,42,84v ac?
with 1,1/2 inch center leg, can i get 2000watt transformer 90,45,0,45,90v ac?
if yes, can u pls tell the specs for these transformers.
thank u.
if you run lossless cut E cores.
center leg would be 39mm wide, and the winding area is 19mm by 58mm
If you can wind the core with a bobbin that is only 1mm thick (or don't use one and just wrap the finished coils in fiberglass)
then if your stack is 200mm long
and you run the flux density at 1.324T
then for a 60-30-0-30-60 transformer your secondary would be 4 coils of 11 turns each, using 9 gauge wire, connected all in series. (8 coils of 12 gauge wire would work as well)
the primary would be 4 parallel coils of 15 awg wire, each 44 turns. all of them would be in parallel for 120vac 60Hz, in series or series parallel for 480 or 240 volts of course.
at 2100 watts RESISTIVE you would be looking at about 56 watts of copper loss and 56 watts of iron loss.
the core would weigh 14 kilograms and the copper would weigh 2.8 kilograms.
if you want 2000 watts into a capacitive input filter then you need a 3000 watt transformer, perhaps bigger.
ever seen a microwave oven transformer?
just like that.
or like this: http://www.dutchforce.com/~eforum/index.php?showtopic=38863&view=findpost&p=339973
if 200mm is too long for you, then you will have to get much larger laminations.
one alternative is to fit two E cores together end to end, so you would have a winding area that would be 19mm by ~118mm.
if you were to make such a transformer you would need to double the turns, keeping the wire the same size.
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you did not tell what type of cores you are using, is it M6 or M50? i design my traffos to 1T at the most, this means more copper turns but the tradeoff is lower heating....
for a 2000 watt traffo with a centre leg of 1 1/2, you will need a stack about 6 inches high.....
hi tony,
the core thickness is .35mm.
so i have to make the bobbin. the problem is bobbin.
is it possible making bobbin from pcb board, if i remove copper from pcb board.
i think pcb board better than nylon bobbin.
in my shop the main voltage showing 235v, and in my house main voltage is 220v so i have to wind suit for this. for primary 0v,220v,235v.can u tell me how the turns wind for primary.
can u tell me the specs for those last post transformers.
I have some beginner questions. I understand the engineering. I have some formal education in that area but I'm having a hard time locating the materials. I live in the US (California)
1) Where to get the EI core laminates in small retail quantities?
2) What kind of paper or other insulations are people using between the layers? and where to get the tiny amount a hobby-builder would need.
3) What kind of varnish are people using. Is the kind intended for wood finish OK? It needs to take heat and few wood finishes are designed to even 85C. Is vacuum really needed?
4) has anyone tried using C-cores rather then EI cores. These look interesting. Silicon Steel C-Cores / Goss C-Cores for 60 Hz and 50/60 Hz Frequencies
My goal is to learn by making a few power transformers and then move to making audio transformers for tube amplifiers and studio equipment (compressors, limiters, mic preamps,...) So my question about c-cores applies to audio transformers.
It looks like maybe a c-core might have the advantage of a toroid but the ease of bobbin winding. And it appears that you can disassemble a c-core. Also I think a c-core would be easy to air gap if needed.
1) Where to get the EI core laminates in small retail quantities?
2) What kind of paper or other insulations are people using between the layers? and where to get the tiny amount a hobby-builder would need.
3) What kind of varnish are people using. Is the kind intended for wood finish OK? It needs to take heat and few wood finishes are designed to even 85C. Is vacuum really needed?
4) has anyone tried using C-cores rather then EI cores. These look interesting. Silicon Steel C-Cores / Goss C-Cores for 60 Hz and 50/60 Hz Frequencies
My goal is to learn by making a few power transformers and then move to making audio transformers for tube amplifiers and studio equipment (compressors, limiters, mic preamps,...) So my question about c-cores applies to audio transformers.
It looks like maybe a c-core might have the advantage of a toroid but the ease of bobbin winding. And it appears that you can disassemble a c-core. Also I think a c-core would be easy to air gap if needed.
sir tony,
this have been talk about in another thread,but i feel free to ask this matter to a master
900w @ 4 R said in need of 1800kva for stereo 900w
most cases in our country and you know it,amateur builder use big traffo as they can,
but resulting into burned output,
my question is what was the rule of thumb regarding this output and transformer balancing,
and please show some traffo computation in different impedance.
8,4,2 R
this have been talk about in another thread,but i feel free to ask this matter to a master
900w @ 4 R said in need of 1800kva for stereo 900w
most cases in our country and you know it,amateur builder use big traffo as they can,
but resulting into burned output,
my question is what was the rule of thumb regarding this output and transformer balancing,
and please show some traffo computation in different impedance.
8,4,2 R
Engel,
the usually recommended transformer size is one times to two times the maximum power output of the amplifier.
For a 900W power amplifier you could use a 900VA to 1800VA transformer. For a stereo amplifier putting out a maximum of 900W+900W you could use a 1800VA to 3600VA transformer.
Your selection of a 1800VA transformer will work.
Burning out of the output stage is a completely different issue. It has nothing to do with the selection of an appropriate transformer. Reliable output stage is down to selecting/designing the output stage to meet the duty you require.
For a ClassAB stage with a target output of 900W expect to use ~3600W of mosFET output devices per channel.
I would recommend that you do not adopt a ClassAB output stage and instead adopt one of the "special" classes designed specifically for ultra high power.
the usually recommended transformer size is one times to two times the maximum power output of the amplifier.
For a 900W power amplifier you could use a 900VA to 1800VA transformer. For a stereo amplifier putting out a maximum of 900W+900W you could use a 1800VA to 3600VA transformer.
Your selection of a 1800VA transformer will work.
Burning out of the output stage is a completely different issue. It has nothing to do with the selection of an appropriate transformer. Reliable output stage is down to selecting/designing the output stage to meet the duty you require.
For a ClassAB stage with a target output of 900W expect to use ~3600W of mosFET output devices per channel.
I would recommend that you do not adopt a ClassAB output stage and instead adopt one of the "special" classes designed specifically for ultra high power.
if you are not doing sine wave testing and just playing music then the traffo should be enough....
my rule of thumb, get the biggest traffo that will fit in your box.....
burned output is a result of poor heatsinking at times....
having big traffo aggravates poor heatsinking, you know that in our place, builders just make do with what is available....
using smaller traffo otoh can result in burned out traffo due to over heating of the copper coils and core saturation when current demands exceeds the capabilities of the iron cores....
it is all a balancing act.....
any of you transformer guys know if this is even possible:
on P Turner's website - page PP OPT calcs Page 3 there is a small diagram/overview of a transformer and the primary and secondary are interleaved [hope that's the right word].
Is this even possible either hand winding or automated ?
After the bottom section of the primary has been laid if you then start the secondary above it and try to wind either in the same or opposite direction the primary winding below basically will tangle every which way ? Or am I missing something completely obvious ?
His diagram seems impossible.
on P Turner's website - page PP OPT calcs Page 3 there is a small diagram/overview of a transformer and the primary and secondary are interleaved [hope that's the right word].
Is this even possible either hand winding or automated ?
After the bottom section of the primary has been laid if you then start the secondary above it and try to wind either in the same or opposite direction the primary winding below basically will tangle every which way ? Or am I missing something completely obvious ?
His diagram seems impossible.