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Old 28th June 2013, 03:50 AM   #11
DUG is offline DUG  Canada
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Quote:
Originally Posted by Reactance View Post

...

Anyway to sample 50 amps is simple, you can get hold of a small toroidal core and build a smalll current transformer CT, run 1 amp through a copper wire and through the core, and see what the sample voltage is, do the math and determine the maximum saturation point of the current core and add some low pass filtering with a simple RC filter. if you dont wanna go through all this effort buy one current transformers are not that expensive and prices are becoming relativity cheap nowadays.

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Transformer to sense 50ADC...I think not.

Even though the link you posted is not in English, I was able to follow most of what they were presenting for current control using the 494.

One of the error amp is feedback for the voltage regulation (Hata Kuvvetlendirici Bölümü (Error Amplifier)) and the other is used as a current limit if configured as a comparator. (Akım Sınırlama (Current limit Amplifier))

They have placed a current sense resistor in the negative output path so the current sense error comparator can use the signal to lower the output in response to the 50A flowing through the sense resistor.

Is this what you want to do?
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Old 28th June 2013, 04:54 PM   #12
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Quote:
Originally Posted by DUG View Post
Transformer to sense 50ADC...I think not.

Even though the link you posted is not in English, I was able to follow most of what they were presenting for current control using the 494.

One of the error amp is feedback for the voltage regulation (Hata Kuvvetlendirici Bölümü (Error Amplifier)) and the other is used as a current limit if configured as a comparator. (Akım Sınırlama (Current limit Amplifier))

They have placed a current sense resistor in the negative output path so the current sense error comparator can use the signal to lower the output in response to the 50A flowing through the sense resistor.

Is this what you want to do?
its a current sense transformer as an example not sure it does 50amps, why wont a current sense transformer not work ??
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Old 28th June 2013, 10:11 PM   #13
DUG is offline DUG  Canada
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I will let a third party explain:

BBC - GCSE Bitesize: Transformers - Higher

or here:

http://www.howstuffworks.com/transformer-info.htm

Hope that helps

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Old 28th June 2013, 10:16 PM   #14
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Quote:
Originally Posted by DUG View Post
I will let a third party explain:

BBC - GCSE Bitesize: Transformers - Higher

or here:

http://www.howstuffworks.com/transformer-info.htm

Hope that helps

I was assuming the CT will be connected to the ac line before the rectification stage.. not the dc output.
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Last edited by Reactance; 28th June 2013 at 10:19 PM.
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Old 16th July 2013, 04:10 PM   #15
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Thank you guys Reactance and DUG are very attentive'll take a more studied give me when I have a problem I ask again ok!

I am very grateful for the explanations!
I'll see if I can use the Transformer to sense the same as they had spoken!
I'm thinking of making this scheme what do you think?
???? TL494?? IRFP460?????

will I be able to regulate the current from 0 to 50A?

Thanks again

Att

Heidern
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Old 16th July 2013, 09:42 PM   #16
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Quote:
Originally Posted by heidern View Post
Thank you guys Reactance and DUG are very attentive'll take a more studied give me when I have a problem I ask again ok!

I am very grateful for the explanations!
I'll see if I can use the Transformer to sense the same as they had spoken!
I'm thinking of making this scheme what do you think?
???? TL494?? IRFP460?????

will I be able to regulate the current from 0 to 50A?

Thanks again

Att

Heidern
I just bought this today a CT up to 100AMPS it will be for a future PIC32
home energy usage monitor project for rainy days.

SCT 013 000 0 100A Non Invasive AC Current Sensor Split Core Current Transforme | eBay

I cannot confirm the circuit works if it does...

you need a fairly comfortable understanding of SMPS why dont you build something simple then move to bigger circuits you can still employee a CT and a TL 494 just not a HV mains version which may blow in your face with the slightest timing error.
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Old 21st October 2013, 07:21 PM   #17
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I appreciate everyone's help, I made a smps with ci 3524 and got to the current control.

Now we need to learn how to calculate the output inductor.

grateful
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