# 24V,30A power suply

Discussion in 'General Electronics Chat' started by ali zeeshan, Feb 7, 2014.

1. ### ali zeeshan Thread Starter New Member

Feb 7, 2014
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hi there every one this is my first experience to post my problem in a forum
the problem is that i want to make a power supply capable of providing atleast 24 volts and 30 amps i am from asia and we have 220 volts running in our system i have a 1000 watt transformer converting 220 into 110 volts can i use that to make a power supply?
anybody help plz i am a student of electronics engineering and have made a regulating power supply but that was 24 volt 1 amp

2. ### Brownout Well-Known Member

Jan 10, 2012
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I guess you can strip about 3/4 of the wire from the secondary. Aside from that, I don't see a good way to use it.

3. ### shteii01 AAC Fanatic!

Feb 19, 2010
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Do you want AC or DC?

4. ### ali zeeshan Thread Starter New Member

Feb 7, 2014
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i want dc current actually i am working on a club car which has a series wound dc motor of 3.2 hp at 48 volts and rated current about 50 Amps.this is my final year engineering project.obviously it is not a good idea to buy battery bank big as 48 volts and 100 amps and that too just for testing purpose, that is why i am willing to make a power supply of my own which can at least supply 24-36 volts and reasonable 25-30 amps i know its not going to be an easy task but i believe that it is achievable so if any body out there can help me i would be very glad and thankful Thankyou

5. ### R!f@@ AAC Fanatic!

Apr 2, 2009
8,785
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Hmm.

220VAC to 110VAC from a 1000W Tx.
U think it can supply 50amps.

WRONG !

Do you know atleast P=VI
1000W = 110VAC X I
I = 1000/110
Is around 9 Amps roughly speaking ( this is not exact )

9 amps is nothing to drive ur motor.

To drive 50 Amps motor from tx would require that the supply should be able to withstand 3 times motor current for start up.

This something that a battery can provide.

even if you can rewind the transformer for say to get 48VDC at with a center tap secondary winding of 36-0-36 VAC, and to get 50A atleast you would need more 1000W

In Watts your motor draws 2.4KW. this just a rounded figure.

And if you manage to find a Tx u would need very powerful rectifier diodes and insane amount of smoothing caps to display proper operation. Roughly for 30 Amps it will be 45000μf Caps

Unless you manage to make a PWM drive to smooth start ur motor.
But this also more complex than the supply

In short.

GET THE BATTERIES. IT"S CHEAPER AND EFFECTIVE

6. ### MrChips Moderator

Oct 2, 2009
12,624
3,451
Ah, a club car. Now you're talking.
How are you going to connect to 220VAC mains? Long extension cord?
Why not use two 12V batteries?

7. ### R!f@@ AAC Fanatic!

Apr 2, 2009
8,785
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batteries are heavy. And he is doing his final year.

Do they dunno these kinda issues. ?

I am stumped.

Still u don't need 100amp batteries. Good deep cycle batteries around 20Amps can run that thing for like 1 minute.
Four of em can give you 48VDC.

8. ### ali zeeshan Thread Starter New Member

Feb 7, 2014
18
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at R!f@@ you didn't get it. i need a replacement other than batteries, also deep cycle batteries are way too expensive. eventually i ll have to use batteries in my project but i want a replacement which i can use to test things like dc speed controller.anyways let me refine my question is there any way i can make a stable power supply providing 36 volts and 25 amps and if i have to make it using a transformer how big that's going to be what would be the rating of components required like bridge resistors etc

9. ### Brownout Well-Known Member

Jan 10, 2012
2,375
998
People sometimes power these motors on surplus welders. If you can find one for cheap ( or free ) you might take some readings on the output voltage. The current capacity is usually specified, and is typically upwards of 225A.

Feb 19, 2010
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11. ### bountyhunter Well-Known Member

Sep 7, 2009
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You need a power supply that can output more than the maximum peak current or it will go into current limiting and the voltage will collapse.

If you use a power supply and a battery, the battery will supply the peaks.

12. ### R!f@@ AAC Fanatic!

Apr 2, 2009
8,785
771
Is building a supply cheaper ?

It might be if you got like a couple of 71VDC 10000uF capacitor.
A 200A bridge. and um yes a 2KW transformer.

If you got them let us know. We can show you how to wire it.

Of course there is no guarantee it would work. It might IF the diodes can supply 1000A surge.

Still dunno how the motor is driven in your club car. Does it use DC or PWM control

13. ### ali zeeshan Thread Starter New Member

Feb 7, 2014
18
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why don't you people get it i wanted to make the supply so that i can use it for testing purpose and may be to charge batteries as well.experimenting with batteries could be costly so that's y i wanted to test every thing with a self made power supply. The car will definitely be running on batteries eventually anyways.... thanks for all the support guys..

14. ### R!f@@ AAC Fanatic!

Apr 2, 2009
8,785
771
OK !

Let's make a supply eh!

But PSU and charging is different. But if you can make a CV with CC, u can charge as long as you keep an eye on it.

So what do you want.

Let's start about with some figures.
CV means constant voltage regulation and CC means constant current regulation.
You can build CV or a CC or both in one.
To me a CV, CC is the way to go. As you can control both Voltage and Current as required.

Meaning Maximum voltage and current you need to supply from the PSU?

By the way, not to be rude or anything but it is not us who do not get anything. It is you who do not understand certain requirements.

15. ### ali zeeshan Thread Starter New Member

Feb 7, 2014
18
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max volt 40 volts and max current 25 Amps

16. ### R!f@@ AAC Fanatic!

Apr 2, 2009
8,785
771
Just Variable voltage, from 0 to 40 VDC is enough, right ?

Maximum Current handling is 25Amps.

Am I correct ?

17. ### ali zeeshan Thread Starter New Member

Feb 7, 2014
18
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yes you got it right

18. ### bountyhunter Well-Known Member

Sep 7, 2009
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I guess I didn't get it because I didn't realize how easy it would be to make an 800 Watt power supply. I probably didn't realize it because I worked in power supply design for 20 years and actually know what it takes to do that.

You need a 800W power supply. You should buy one. The amount of knowledge that would have to be transferred to design and build it far exceeds a do it yourself project.

Unless you just want to spend a lot of money and time building it, you should buy one.

somehow you seem to think power supplies are dirt cheap and batteries are expensive but the reverse is true. A 24V battery could be built up from two 12V car batteries, they could be kept charged up by a cheap trickle charger.

19. ### ali zeeshan Thread Starter New Member

Feb 7, 2014
18
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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

Sep 7, 2009
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