# Rectifier



## RikkiRicardo (Feb 10, 2013)

Hi
Here in Romania it's hard to find an rectifier with voltage control yes i can buy one but shipping is the killer
So i would like to build one anyone who may have schematics for a rectifier 0-12 volts 0-200 amps
or anyone that can tell me what equipment that i can convert this to the rectifier
what we are building is a copper electrowinning unit we want the unit to recover
1.1/2 kilos or more per hour regards the tanks is no problem to do the calculation
once i have the rectifier why we want to do this is because i buy my acids very cheap wish i could ship to the Forum members
so this makes more sense to recover the PM from the sludge as we will be treating first with
sulfuric bath first to remove lead tin anything that dissolves in the first bath
then AR to dissolve everything then recover copper,then work with the sludge for the PM
any input on the will be great

Rikki


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## DONNZ (Feb 10, 2013)

Only thing I can offer: search:

how to build a rectifier

Gives you a good starting point.


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## RikkiRicardo (Feb 10, 2013)

Only thing I can offer: search:

how to build a rectifier

Gives you a good starting point.
I do more searches per day then you can ever dream
are you real???? DONNZ i have searched your posts with no interest on what you do
first read my post i have been in this business I'm sure longer then you
and I'm sure i know enough about searches Sorry everyone but this person should do his own searches
as i have done this before posting I'm not looking for a small unit 
all that i ask is there an equipment that can be modified to my needs
Sorry everyone for what i wrote i just feel his post was not right.
DONNZ please don't even response to this end of story
if anyone can help please and thank you

Rikki


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## butcher (Feb 10, 2013)

You need a transformer, one two time the current you plan to use, the primary winding needs to be the voltage you will be using, the secondary needs to be around 12 volt, but normally the secondary winding is on the outside, so if you cannot find the correct secondary you could try winding your own, you can cut off the secondary winding coil (if the wrong turns) and wind your own secondary (using epoxy coated, or even plastic coated solid wire is best, but at the amperage's you’re talking about you will most likely have to use stranded insulated wire which is capable of handling 2 times the current) (2/0 AWG copper can handle 200 amps) you will use the turn ratio to get desired output voltage. You could also experiment, by winding several turn check the voltage and figure how many turns you will need, 
Use OHM's law to do your calculations and figure.
A transformer two (or more) windings coils, the voltage is determined by how many turns of the turn wire on each coil, or turn ratio, primary coil to secondary coil, say I have 100 turn primary and a 10 turn secondary windings 100:10 turn ratio , if I put 100 volts to the primary I will get 10 volts on the secondary, now I turn the same transformer over, an put 100 volts (to the 10 turn coil) I will get 1000 volts out of the other coil.

Watts in equal’s watts out 
Say I want to run 10 volts secondary at 200amp (OHMS law) 10volts X 200 amps = 2000watts
So this means my primary will be 2000 watts, say I am using 100volts to power the primary then:
2000 watts / 100 volts = 20 amps, so my primary will pull 20 amps of current.

This will give you ten volts of alternating A/C voltage, you will now need one or more diodes to convert this A/C voltage to DC voltage, so here you need some very big diodes these may be hard to find I would almost double the current of the diodes to be safe so the power supply would not blow its diodes and it would last (maybe a minimum of 300A to 400A diode) here is an example:

http://www.vishay.com/docs/93545/sd300nr.pdf.

You want to make your power supply half wave or full wave DC, half wave could use one or two diodes the full wave will use four diodes wired in a rectifier bridge.

http://www.bristolwatch.com/ele/basic_ac_rectification.htm
This will get about 10 volts A/C volts before the full wave rectifier, and after the diode bridge about 1.414 times higher so about 14 volts DC at 200 amps.
Very large capacitors could also be added (double voltage for safety), if you wanted a smoother DC voltage.

A variable transformer or just tapping the windings of your transformer, would give you more control of voltage or the ability to change the voltage

There is quite a bit more to this that you would need to study, but basically you can build your own.
And hopefully this will point you in a direction to study it.
This is just a simple DC power supply on a little bigger scale.
Just like building a small one, study everything and be careful, make sure you understand everything about it before you build it or get some more help.


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## element47.5 (Feb 10, 2013)

By the time you are talking about 200 amps, you are talking about electromagnetic power that can move the coils and if it is not carefully designed with low core losses, such a transformer can wreck itself, either by moving the wires and scraping the insulation, or by excess heat. Or both. It's possible you may be able to adapt a welder to supply this much current. 

I once built a 50 amp transformer....it was wound on a toroid about 10 cm in diameter and had 24 secondary windings of either 1-1/2 or 2-1/2 turns, all connected in parallel. It worked very well. 

Now, you have to solve the problem of where you're going to get a 200-amp capable diode. They certainly exist. 

You are going to have to search for items that are used to carry very, very heavy current. Welding; motors or transformers that come from a railroad application. Elevators. Fork lift charger. And it's also possible that you'll have to supply cooling for such an item, both the transformer and the diode.


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## RikkiRicardo (Feb 11, 2013)

Butcher/element47.5
Thanks with this info it will lead me in the right direction
i will keep you informed on this project


Rikki


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## nickvc (Feb 11, 2013)

Rikki I know you said buying one was not the way forward but there has to be secondhand rectifiers not too far from you, a lot of the large computer suppliers moved their plants to eastern Europe years ago for the cheap labour, they are probably all in Asia now,so there must be units available a van drive away, do a google search for secondhand machinery near you, you might get lucky, I found one on my doorstep, 10 volts 50 amp for about 1/3 the price for a new one.


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## DONNZ (Feb 11, 2013)

If it was irrelevant, why respond to it?

That's a rhetorical question. 

"DONNZ please don't even response to this end of story"

Chalk that one up to things you can't control. 






RikkiRicardo said:


> Only thing I can offer: search:
> 
> how to build a rectifier
> 
> ...


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## RikkiRicardo (Feb 11, 2013)

nickvc glad to hear from you
yes hear in Romania was the biggest production of all Europe at one time everything got sold for scrap iron an copper 
trust me i searched this is why i ask is what i can convert to what i need yes i can pick up the whole unit but the transport cost is the killer
my fume motor here is 1500 euros i had it shipped from china for 500 dollars for for unit with UPC that was 30 kilos the rectifier is what 90 or over kilos
plus the price of the unit that is the killer nickvc I'm in UK all the time we should meet for a pint 
this summer will be a great summer for PM second hand units i have not tried outside of Romania because of the shipping 
so i would like to build or convert one to my needs.

Rikki


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## RikkiRicardo (Feb 11, 2013)

DONNZ
please only to something that you know as i asked you read what i was asking for
and stop wasting space this will be my last reply to you.I have seen all your reply's to people Do a search on your reply's. 

Rikki


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## butcher (Feb 11, 2013)

Ok
That is enough of that.


If we cannot say something nice, or helpful, lets just not say anything.

This could just get out of hand and create bad feelings.

We all need to study and search if we wish to learn to do something.

Sometime's we just need a little help getting pointed in the right direction to begin.

I do not see where either of you are right or wrong, in anything you have said, but my gut feeling is if this continues no good can come from it.

Let us just continue to help each other the best we can, and not take offence at how another member may try and give that help.


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## DONNZ (Feb 11, 2013)

I know my post are a little ruff around the edges, but I mean well.

But publicly belittling another member is totally unnecessary.


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## mikeinkaty (Feb 23, 2013)

World War II aircraft engine starters had 3 big transformers with about 8 or 10 input taps on each. Using different input taps you could get anywhere from 20 to 40 volts on the output windings at 220 Volts. The output windings were about 1/4" (6mm) diameter and would handle 200+ amps. The transformers were intended to be hooked in a Y-Delta 3 phase configuration. The input side was Y and the output side was delta. I modified them putting 6 big fan-cooled aluminum heat sinks in the bottom each with 250 amp rated silicon diodes. This gave 3 phase full wave rectification. They made great golf cart battery chargers where each unit would handle up to 10 carts. I modified about 30 of these for sale to golf courses. The units could be found at army/navy surplus warehouses. This was when 3 of my kids were in college all at the same time!

Each of the 3 transformers weighed about 100 pounds.

Hope that gives you some ideas.

Mike


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## nickvc (Feb 23, 2013)

Rikki I'd enjoy a few beers next time your here in the UK..
A thought as you say your a regular visitor why not buy your second hand rectifier here or elsewhere in Europe and have it moved by road back to your works. We have a large eastern European population now so I'm sure trucks must be moving goods both ways.


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## RikkiRicardo (Feb 23, 2013)

Yes nickvc 
i can pick it up there with no problems transport cost is the problem when i ship over there the cost is 2,500 euros 12 tons now for one skid they want 300 euros
Turkey has a new one for 450 euros now i will look at the transport cost i have found something in Poland still waiting for price and shipping cost
So much time lost as I'm sitting on 3000 liters of copper solution waste and how much other metals might be in there 
so if i could put one together would be great i have in till next week to solve this problem as my tanks will be here also they built me one rotating tank for the
Sulfuric bath that was easy to get here anything else is very expensive 1 front bearing for my 89 Dodge Dakota convertible they wanted 1500 euros when i was 
back in Canada i got it for 70 dollars My acid proof motor they wanted 2000 euros i had it shipped from China for 500 dollars total price
this is another reason i was looking to see what i can convert to my needs.An yes we will have to go and have a some pints.


Rikki


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