Rules | Recent posts | topic RSS | Search | Register  | Log in

Big Problem!!

 
Post new topic  Reply to topic    EDAboard.com Forum Index -> Elementary Electronic Questions
Author Message
zezito



Joined: 07 Sep 2004
Posts: 4
Post28 Oct 2004 12:01   Big Problem!!
I have a big problem!!
There is a rectifier (IN 380V ; OUT 20V 50A without a transf.) connected to an anodizing cube. when start to raise the voltage, the current strats to flow thru the bath when the voltage reaches +- 10V!
Now the problem is how to make the current flow thru the bath with less voltage??
I attached a file so that you can see what i think it will solution this problem, but please write your opinion!!!

Thank you all

Sorry, but you need login in to view this attachment
Back to top
epp



Joined: 04 Mar 2004
Posts: 265
Helped: 8
Post28 Oct 2004 12:25   Re: Big Problem!!
You have also to measure all currents It, I1 and I2 with current clamp meter. After that calculate total power load (you must not overload your rectifier).

I think that you forgot to calculate or measure resistance of bath. Total resistance in your cicruit is R in paralell to Rbath and it will be smaller than any of it. Also bath resistance is of nonlinear type (I suppose). Try to use bigger R to limit current.

total load P = total resistance * total current^2 (<=1100W)
Back to top
Frikkie



Joined: 28 Oct 2004
Posts: 19
Post28 Oct 2004 13:00   Re: Big Problem!!
Quote:

I have a big problem!!
There is a rectifier (IN 380V ; OUT 20V 50A without a transf.) connected to an anodizing cube. when start to raise the voltage, the current strats to flow thru the bath when the voltage reaches +- 10V!
Now the problem is how to make the current flow thru the bath with less voltage??
I attached a file so that you can see what i think it will solution this problem, but please write your opinion!!!

Thank you all


I think you forgot to add a comment to the file. Can't see it.

I agree with epp. You need a resistor to limit your current.
Do you know how much current you circuit requires?
If you to you can work out the total resistance to get the value
for the limit resistor.

But this will only limit current not the voltage. You said you required
less voltage. If I see the schematic I could give some advice.

Hope this helps.
Twisted Evil
Back to top
Frikkie



Joined: 28 Oct 2004
Posts: 19
Post28 Oct 2004 13:12   Re: Big Problem!!
Sorry had to wait for the picture to come trhugh.

Try a parrallel resistor of equel size.
That should devide the voltage in half. But if the
bath has resistance you will need to lower it.

epp already stateted that.

Lets say the bath has a 10E resistance than place a
90E at R2 and the 1E make it a 100E. The problem is getting a 90E
resistor.

Good luck

Sorry, but you need login in to view this attachment
Back to top
Post new topic  Reply to topic    EDAboard.com Forum Index -> Elementary Electronic Questions
Page 1 of 1 All times are GMT + 1 Hour


Abuse
Administrator
Moderators
topic RSS 
sitemap