24V,30A power suply

bountyhunter

Joined Sep 7, 2009
2,512
ok ok i got and am convenced that making a supply would be difficult but i was upset for the fact that every body worried about the fact that how i was going to run a club car motor with the power supply that annoyed me
OK. We tried to explain to you that DC motors require very high peak currents which a power supply can not provide but a battery can.

Good luck
 

R!f@@

Joined Apr 2, 2009
10,007
I am already in the design stage of My Bench PSU.
It is 4 separate completely isolated supplies build into one.

I needed higher voltages like upto 60VDC or so. But it is not easy to go that voltage for me so I settled with 0-30VDC ones. That is why I am building 4 ones so I can series connect them when I need to.

In short my PSU is individual PSU's each capable of 0-30VDC CV @ 0-10A CC.
This way I can go as high as 120VDC at 10A by series connection
And if I needed high current I can get 30VDC at 40Amps, or 60VDC at 20Amps (dual).

Series parallel connection is possible with proper care and diodes.
But you won't need that.

What I am saying is that I can only help you with 0 to 30VDC one. My one can go to 25Amps by adding more power transistors and are more powerful transformer. Bu I do not need to. So in short My circuit can be modified for even 50Amps if needed.

I cannot design a one that goes to 40V with regulation as I tried with the one I was building. I can get load regulation up to 30V. That was the main reason I am building multiple ones.

You can do my design if you wish.
I can change the components for you to handle 25 Amps.
But to get to 40VDC you have to make two units and connect them in series. It is completely safe to connect in series as long the PSU does not share the transformer secondary. This way you would have 0-60VDC @ 25Amps max PSU.

Mind you it would be heavy. I can barely lift my transformer as it is rated at 2KW. 4 Secondary windings at 10 amps each.

If you wish to make mine tell me.

If there is another here who is willing to give u a diagram of such capacity I am willing to change my options too
 
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Thread Starter

ali zeeshan

Joined Feb 7, 2014
18
at first i was desperate and i thought that i would be able to make a linear power supply of that much power rating just because i made a similar smaller one but now i realize that i can't make that much big power supply,i also made a search about smps (Switch mode power supply) i have read about it only a bit so guys is it also tough to make an smps?
 

Thread Starter

ali zeeshan

Joined Feb 7, 2014
18
at R!f@@ i ll be very thankful to you if you can give me the design of your supply @0-30v dc, 10A and am ready to make two or three of these to increase current rating
 

R!f@@

Joined Apr 2, 2009
10,007
0-24V or 30V is easy cause there is no much difference.

The main issue is the Transformer. It was for me.
Tell me where you are located? Your country tht is.

My Current PCB layout has the CV and CC regulators plus the Volt and Ampere meters too.
I do not think it was easy for you to make it yet. I am changing some options as it is evolving for easy trouble shooting.
I believe that diagram is somewhere in this forum. I need to look for it.

You have to make a PCB for it as vero board assembly is quite difficult.
 

Thread Starter

ali zeeshan

Joined Feb 7, 2014
18
@ bounty hunter i apologize if i made you angry i just want to know that what size of linear power supply i can make easily i mean the highest amp i can reach, and obviously i would be glad if i can get some basics from you thanks
 

Thread Starter

ali zeeshan

Joined Feb 7, 2014
18
i cant rewind a transformer but we have got some electricians over here who can do this job and they can make a transformer of what ever rating you ask them to...
 

R!f@@

Joined Apr 2, 2009
10,007
It is easier to built with one transformer than use multiple ones.
It's up to you.

You can use multiple secondary windings if you prefer for separate supplies.
I am using 30VAC center tap per secondary ( Full loaded voltage ). It's rated at 12 Amps continues.

So for one supply I am using 15-0-15 VAC secondary. The center tap configuration is used to minimize power dissipation (heat loss) in Power transistors. My design is based on this. So if you want me to help on this you need a center tapped secondary winding.
Remember that you should get 30VDC when the secondary is loaded to 10 Amps with a load. Which means the unloaded value will be like 33 to 35VAC. This value will decrease when the secondary is supplying high currents. So the loaded voltage needs to be at minimum voltage which is 30VAC ( 15-0-15 VAC) if you ignore this fact at u rewind the former for 15-0-15VAC when no load then ur output will be lower like 25VAC or so at full load
What do you have in mind?
 

Thread Starter

ali zeeshan

Joined Feb 7, 2014
18
i think i should go for 20-0-20 VAC secondary for one supply,
we have 220 volts coming in our house here so i think i need almost 450-500 watts transformer right?
 

R!f@@

Joined Apr 2, 2009
10,007
Nope !

Transformer is rated by VA. Volt-Amp.
Higher secondary will create issues like higher voltage smoothing caps and more power loss by the transistors.

U need to use proper sized wires at the secondary that can handle 12Amps while delivering 15-0-15 VAC.
You don't need to go to 20-0-20. It's a waste.

For ex:

You are going to build one supply.
Out put is 30VDC @ 10 Amps.
Mains is 220VAC.

So the VA rating is basically 30 X 10 = 300VA.
This just to show you roughly. U need a 300VA transformer . 15-0-15VAC Secondary @ 10 Amps.

The winding guy should know what size core and primary wire size to use.
If you can take apart ur 1KW former than you can find the size of the secondary wire.
You said it is 110VAC secondary one, so let's say it is rated at 1000VA.
Which means the secondary can supply maximum of 1000VA/110VAC = 9.09 Amps.
That is the maximum current the secondary can handle.
But remember these a rough figures as 1000W is not exactly 1000VA. They are bit different cause Transformer are reactive. Not Resistive. But for these kinda application it will work As long as you beef up the wire sizes up a bit.

So you took apart the 1000W transformer. Then you should be able to see the secondary wire size. This is roughly 9 Amps. So if you want it handle 12Amps, u can use thicker wires than it currently uses. Like 1.5 times thicker. This way you can be sure it can definitly handle more than 9 amps. Not 1.5 times high current but a couple of Amps more like 12 Amps

But if you want to make one transformer then just tell the guy you need a 300VA transformer. Secondary voltage needs to be 15VAC-0-15VAC. Primary voltage is what you use, nothing more.
By telling him the TX is 300VA you are telling him that with 15-0-15 secondary ( total is30VAC) the secondary current capacity is 10 Amps max.
 

MaxHeadRoom

Joined Jul 18, 2013
30,795
In your OP you mention a 1kva transformer, so the secondary would be rated around 9amps.
Why not strip off enough turns to equal ~17v (0-17) and put a bridge rectifier, and cap.
If you want to know the turns/volt, just wind on (or take off) 10 turns and see the difference.
Measure the tens turns on and extrapolate the amount you need to remove.
If you are a student of Electrical engineering it will give you some hands-on experience.
I modify most of my transformers, but tend to use Toroidal type, much easier to wind on or remove.
Max.
 

R!f@@

Joined Apr 2, 2009
10,007
In your OP you mention a 1kva transformer, so the secondary would be rated around 9amps.
Why not strip off enough turns to equal ~17v (0-17) and put a bridge rectifier, and cap.
If you want to know the turns/volt, just wind on (or take off) 10 turns and see the difference.
Measure the tens turns on and extrapolate the amount you need to remove.
If you are a student of Electrical engineering it will give you some hands-on experience.
I modify most of my transformers, but tend to use Toroidal type, much easier to wind on or remove.
Max.
He can if he can take it apart.
It would be better for around 15 amps by doubling the winding I think. ans reducing the secondary turns to get he desired AC voltage
He can very well make a dual supply from tht transformer

With a 1KW tx he can get two secondaries of 30VAC @ 15 Amps Each. Not bad, if he can straighten wires and wind it. Eh!
 
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