# How to wind a step up transformer ?

I need to make an ac step up transformer with an input from the main, output of 400v ac to connect to the a bridge bridge rectifier.
The bridge rectifier number is D35XB60.

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2 years ago

TommyT1 is not crazy !

A transformer does not create power actually it looses some in performing its transforming job !

So if your step up is doubling voltage 220 VAC => 440 VAC at 30A out that means a 60A input ........ 440 x 30 == 13,200 W == 220 x 60 == 13.2 KVA.

Why 440 VAC ?? ..... well they are standard.

Here is a 440:220 control transformer only 7.5 KVA which is Half your size.

Height 14.75 In., Depth 11.75 In., Width 9.75 In and only costs \$1,351.54

And remember you will need two.

..

Then again starting at 220V 4.5A the output will be 440V 2.25A at 1KVA actually available [ second picture ] for about \$156 and you only need one !

mind power (author) 2 years ago

sorry but there is a little mistake in the information i gave you..............

input current is maximum 5 amps

output current is 1 amp

2 years ago

You have a 220 to 440 VAC transformer and you want a 1A output which means a 2A input [ Remember 2:1 ratio ].

After my long dissertation as to current capacity inverse to voltage ratio.

The transformer power rating 0.44 KVA ~ 1/2KVA seen used for as low as \$20 on eBay...

mind power (author) 2 years ago

input voltage - 220v

output voltage - 400v

input current - 3 to 5 amps

output current - 30 to 34amps

core type - ferrite E core

2 years ago

To design a transformer the window size is needed and will decide how much wire and what size gauge can be placed into that opening.

The core magnetic material BH curve needs to be known.

Ferrite material is made to allow high frequency because of a low loss narrow BH curve... This is Good because it makes a transformer small BUT it is not effective at transforming the 30A high currents you want and you have to generate the high frequency yourself.

Household frequency is 60cps or hertz in USA and 50 Hz in Europe.

TommyT12 years ago

call me crazy but W=IxV

30 amps at 400v is 12kw and 5 amps at 220v is 1.1kw

where are we getting these magical amps from? it steps up voltage not current.

for yoursake i hope I'm just crazy

rickharris2 years ago

An input voltage

A, output voltage

An output current

The input current.

Core type.

The step up is the ratio of turns on the primary to the turns on the secondary.

The wire gauge will be related to the current required.

2 years ago

And volt seconds of the core material.

2 years ago

+1