transformer for Legend Stage MK2 (65-0-65V)@10A

[sekhar]

I have almost completed Legend Stage Mk2 I just need the power supply to power it up So i need wind my transformer ............ So here r the data for the transformer winding as i am not very sure that my calculations r very correct plz help me out with this:-
CORE TYPE = EI
VA=1300
WIDTH OF CENTRAL LIMB=2 INCH
TURN PER VOLT = 1
PRIMARY CURRENT = 6.64A
PRIMARY CONDUCTOR DIAMETER =1.9mm(15 SWG)
NO OF PRIMARY WINDING = 230
SECONDARY WINDING CURRENT = 10A
SECONDARY CONDUCTOR DIAMETER = 2.488 (13 SWG)
NUMBER OF SECONDARY WINDING = 68 + 68
WINDOW AREA = 1699mm^2

PLZ HELP ME WITH THE CALCULATIONS CORRECT ME IF I AM WRONG

REGARDS
SEKHAR

[Tony]

sekhar,

are you using the standard EI-200?

[sekhar]

IN my country the EI cores have numbers such as 6,7,8 i have no idea about EI-200 the spec of the EI core i intend to uses is

core no 43


the core no 43 as shown has a window area of 1905mm^2 but the required window area is 2043mm^2 by any means is it possible to build the transformer in the given core??????????????????????

regards
sekhar

[sekhar]

Originally Posted by sekhar

I have almost completed Legend Stage Mk2 I just need the power supply to power it up So i need wind my transformer ............ So here r the data for the transformer winding as i am not very sure that my calculations r very correct plz help me out with this:-
CORE TYPE = EI
VA=1300
WIDTH OF CENTRAL LIMB=2 INCH
TURN PER VOLT = 1
PRIMARY CURRENT = 6.64A
PRIMARY CONDUCTOR DIAMETER =1.9mm(15 SWG)
NO OF PRIMARY WINDING = 230
SECONDARY WINDING CURRENT = 10A
SECONDARY CONDUCTOR DIAMETER = 2.488 (13 SWG)
NUMBER OF SECONDARY WINDING = 68 + 68
WINDOW AREA = 1699mm^2

PLZ HELP ME WITH THE CALCULATIONS CORRECT ME IF I AM WRONG

REGARDS
SEKHAR

error
window area=2043mm^2

regards
sekhar

[Tony]

ok, that is EI-200, i can not shake off the imperial units in my head.....i do however use both at the same time...

so you have a window of 1 inch x 3 inches, or 25mm x 75 mm.

80% of available window is for the copper wires, 50% of which is for primary coil and 50% for secondary coils.

these are your guides, the actual number of primary turns will depend on these guidelines.....

[sekhar]

as u see tony the given core has a window area of 1875mm^ but the needed area is 2043mm^2 so how do i cope up with that is there any other way without using a bigger core..................??????????????????


regards
sekhar

[sekhar]

hey cant an body help me with the design of this transformer i am newbie ,,,,,,,,,, I have done most of the calculations kindly help me in selecting the right core .................



regards
sekhar

[Tony]

are you using grain oriented or non-oriented steel? i ask becasue there is significant difference between two types...

[Tony]

ok, you need 4inch stack of 2 inch center leg core.

#15 primary will have 44turns per layer so 5 layers are needed and the copper build-up is 7.25 mm...

#13 secondary will have about 35 turns per layer, 4 layers are needed and coil build-up will be 7.6 mm..

total build-up is 14.85, so that you will still have 10mm for bobbin and insulations to play with...

i strongly reccomend you wind your secondary biffiliar so as to have exactly the same secondary voltage....

[sekhar]

Originally Posted by Tony

ok, you need 4inch stack of 2 inch center leg core.

#15 primary will have 44turns per layer so 5 layers are needed and the copper build-up is 7.25 mm...

#13 secondary will have about 35 turns per layer, 4 layers are needed and coil build-up will be 7.6 mm..

total build-up is 14.85, so that you will still have 10mm for bobbin and insulations to play with...

i strongly reccomend you wind your secondary biffiliar so as to have exactly the same secondary voltage....

I am using CRGO core or commonly refered to white core at my place .........
tony ur and my calculation does nt match
No of turns per layers in primary=3*2.54/1.9=40
no of layers required =230/40=5.75 ~ 6
Coil build up = 6 x 1.9 = 11.4mm
No of turns per layer secondary = 30
NO of layers required = 4.5 ~ 5
Coil build up = 5 x 2.488 = 12.44
total coil build up in primary & secondary = 12.44 + 11.4 = 23.8
That quite a narrow margin I think........................
And how did reach the figures that u mentioned above cause according to ur calculation
#15 primary will have 44turns per layer so 5 layers are needed and the copper build-up is 7.25 mm...(5 x 1.9 = 9.5mm)& how r u placing 44 turn in a 3inch bobin it could accomodate max 40 turn
#13 secondary will have about 35 turns per layer, 4 layers are needed and coil build-up will be 7.6 mm..(2.488 x 4= 9.952)
total build up =9.952+9.5= 19.452mm

regards
sekhar