How hard would it be to modify a power supply to increase amps?

[wolfdagon]

I found a 48V power supply for about $40 but it is only 2 amps. Is it possible to modify it to give 8-10 amps? If so, how hard/expensive would it be? Could I make an easy change which would sacrifice some voltage for more amps? If I could get it to 40-42V and 8-10 amps that would be great.

[holbieone]

i don't think it will work for that much change

first you need to know how many amps the transformer will kick out

then you can replace the bridge rectifier or diodes with ones that are rated for higher amps

do a Google for power supply schematics

[wolfdagon]

Probably a silly question but if I got two 24V 5A supplies could I connect them to make a 48v 10A supply?

[CJL5585]

Originally Posted by wolfdagon Probably a silly question but if I got two 24V 5A supplies could I connect them to make a 48v 10A supply?

NO

If you wired the supplies in series, you would have 48 Volts at 5 Amps.

If you wire them in Parallel, you would have 24 VDC at 10 Amps.

Jerry

[FPV_GTp]

Originally Posted by wolfdagon I found a 48V power supply for about $40 but it is only 2 amps. Is it possible to modify it to give 8-10 amps? If so, how hard/expensive would it be? Could I make an easy change which would sacrifice some voltage for more amps? If I could get it to 40-42V and 8-10 amps that would be great.

Hi wolfdagon

have a look at this thread http://www.cnczone.com/modules.php?n...warticle&id=27 there is more information on the front home page on www.cnczone.com

Hope this article is of help , that is the problem with website so much information on here , i need to take a speed reading course to increase my reading speed from 20 words a minute to 1500 words a minute

cheers

[max_imum2000]

my company uses switching powersupply a lot.
very nice size and very light weigh compared to the transformer type (3kg only).
they come in 48v 10amp, and 48v 20amp
i think the price is 180$ for the 10amp, i can send you few if anyone intersted.

[wolfdagon]

Originally Posted by CJL5585 NO If you wired the supplies in series, you would have 48 Volts at 5 Amps. If you wire them in Parallel, you would have 24 VDC at 10 Amps. Jerry

Okay, That makes sense.

Two more questions, then.

1) Is it more important to have more volts or more amps? I have now found a few identical 24V 7.2A power supplies. If I am understanding everthing that I have read in the zone I need around 32V 6A for my three motors, so I could wire two of these in series and be ok. However, I would like to be able to add a fourth axis later. This would require 42V 8A. Would the 7.2 A make that much difference?

2)If so, would it be possible to wire up three of these supplies in a combination of series parallel to get what I need? Again, maybe a stupid question.

Thanks for all replies.

[holbieone]

Originally Posted by wolfdagon Okay, That makes sense. Two more questions, then. 1) Is it more important to have more volts or more amps? I have now found a few identical 24V 7.2A power supplies. If I am understanding everthing that I have read in the zone I need around 32V 6A for my three motors, so I could wire two of these in series and be ok. However, I would like to be able to add a fourth axis later. This would require 42V 8A. Would the 7.2 A make that much difference? 2)If so, would it be possible to wire up three of these supplies in a combination of series parallel to get what I need? Again, maybe a stupid question. Thanks for all replies.

if you have 3 12volt 2amp motors you will need a 12volt 6amp power supply

adding another 12volt 4amp motor you will need a 12volt 10amp power supply

if the motors are different voltages you will need a power supply for each voltage

[sdantonio]

Originally Posted by wolfdagon I found a 48V power supply for about $40 but it is only 2 amps. Is it possible to modify it to give 8-10 amps? If so, how hard/expensive would it be? Could I make an easy change which would sacrifice some voltage for more amps? If I could get it to 40-42V and 8-10 amps that would be great.

I read something on the xylotek page a long time ago. If I remember it right their claim was even though your motors may be rated for 5A, 3 motors may work fine on considerably less (i.e. you don't need anywhere near 15A for the system). I don't know if that argument is specific to something in the chipset they use or if that can be made as a general argument.

Now if you have 4 of those 24VDC power supplies... then your in business.

[sdantonio]

Originally Posted by wolfdagon Okay, That makes sense. Two more questions, then. 1) Is it more important to have more volts or more amps? I have now found a few identical 24V 7.2A power supplies. If I am understanding everthing that I have read in the zone I need around 32V 6A for my three motors, so I could wire two of these in series and be ok. However, I would like to be able to add a fourth axis later. This would require 42V 8A. Would the 7.2 A make that much difference?

From the little I understand of this, motor speed is a function of voltage, motor torque is a function of amperage.

[max_imum2000]

guys , guys
you only need 2/3 of the amp rated on the motors
example
3 motors 3amps each
total is 9amp, but in the real work you only need
a supply of 9x(2/3)=6amps
to be on the safe side lets say 7amps

[ger21]

Originally Posted by max_imum2000 guys , guys you only need 2/3 of the amp rated on the motors

Not always. It depends on the drives. Correct with Geckos or a Xylotex, but with a board like a Stepperworld, you'll actually need 2x the rated current per motor (full current for each coil of the motors).

If I am understanding everthing that I have read in the zone I need around 32V 6A for my three motors, so I could wire two of these in series and be ok. However, I would like to be able to add a fourth axis later. This would require 42V 8A

If you're talking about steppers here, adding more motors shouldn't requie an increase in supply voltage, if the motors are all rated the same voltage. Whether you use 1 motor or 3, the required voltage would be the same.