Size E in that chart, 120VA.

Bob

 

And perfectly consistent with those in post #4

 

Size E in that chart, 120VA.

Bob

how can i compute the output secondary amps then, sorry im totally new

 

how can i compute the output secondary amps then, sorry im totally new

Divide the VA by the voltage

 

my transformer is center tapped, 28v-0-28, so 120VA/28 = 4.2A.
is my calculation correct?
so if i use the 28-0 on brideg rectifier, then it can easily handle 4A or current?

below is the diagram of my transformer

 

4A X 28v = 112Va consumption.
Are you using a bridge on one side , or 2 rectifiers with the C.T.?

 

i will set up like this

 

hi again, my transformer weighs 1.25kg, its outer diameter is 94mm, height 39mm, inner diameter is 45mm.

Please measure the Primary DC resistance, and each secondary DC resistance, then post.

 

what you mean dc resistance?

 

what you mean dc resistance?

Use an ordinary volt/ohm meter and measure the resistance of the windings (just like you would to measure a resistor)

 

primary is 21.1 ohms,
between 28 and 0 is 0.6 ohms
between 28 and 28 is 1.3 ohms

 

This article shows the two methods of obtaining the rectified output, one uses one side of the secondary as you show, the other, two diodes instead of four, and uses the C.T.
https://www.electricaltechnology.or...fier-types-of-rectifiers-their-operation.html

 

hi! Please help me identify the current output of this toroidal transformer. There is no marking indicating how much amps on the output. The only marking is BX1201, the primary is 230VAC/50Hz, and secondary is 28Vx2-0-28Vx2, it has a 1.5A fuse in the primary. I got this transformer from a speaker with built-in amplifier. The speaker is MG Audio Box-1201 550W. I'm planning to use this transformer to build my own linear bench power supply, maybe 0-30VDC 5A if it can. I'm attaching the actual picture of the transformer below for reference. Thank you!

Doesn't that look like a transformer symbol to you?



Primary on the left, center-tapped secondaries on the right...

I've attached information on toroids. Don't know where I got that document from. Also, you might still find info at ludens.cl - if he's still around, he knows more about transformers, than anybody I've ever known. I learned from him- the man is brilliant.

 

...and I'm just throwing this out there. Usually, in a transformer, if you are dropping voltage, you're gaining current. If you're dropping current, you're gaining voltage. The energy transferred is the same.

 

Doesn't that look like a transformer symbol to you?

View attachment 267619

Primary on the left, center-tapped secondaries on the right...

I've attached information on toroids. Don't know where I got that document from. Also, you might still find info at ludens.cl - if he's still around, he knows more about transformers, than anybody I've ever known. I learned from him- the man is brilliant.

thank you, ludens. cl website is still alive and contents were very interesting! i dont know if its still updated but how can i reach the other? sorry o.t

 

primary is 21.1 ohms,
between 28 and 0 is 0.6 ohms
between 28 and 28 is 1.3 ohms

Ok....this is likely a 120VA transformer

 

thanks mate, again thank you very much to all of you, i really appreciate all your help. how many amps can i extract then if i use the two 28v, 56v in total? will it double or stay at 4A?

 

No, it will go to 2A each.

VA means just that, volts x Amps. At 56V you can use only 120 / 56 or a little over 2A

Bob

 

thank you, ludens. cl website is still alive and contents were very interesting! i dont know if its still updated but how can i reach the other? sorry o.t

In one post I provided an attachment- you should be able to click it and save it.

 

thanks mate, again thank you very much to all of you, i really appreciate all your help. how many amps can i extract then if i use the two 28v, 56v in total? will it double or stay at 4A?

current out is a function of current in, in accordance with the transformer conversion between volts and amps as I previously mentioned-- and wire diameter. Smallest wire-diameter in line with NEC electrical codes determines max amps allowed without melting the lacquer on the transformer windings (which would make it short).

I recommend you get this book- it's $15 at Amazon- but well worth it.

Title: Understanding Basic Electronics, 1st Ed.
Publisher: The American Radio Relay League
ISBN: 0-87259-398-3