DC Power supply rating

Thread Starter

superway

Joined Oct 19, 2009
125
Hello,
Can I ask you a question about DC power supply?
I looked many websites, sometimes I see a DC supply 60V/80A the output rating up to 1200W.
But sometimes I see DC supply 60V/80A and the Output rating more than 3000W.
What is the difference between of them, even they have the same Voltage and Current?
Thanks,
Ken
 

Reloadron

Joined Jan 15, 2015
7,888
Watts = Volts * Amps

A power supply rated to deliver 60V @ 80 Amps is a 4,800 Watt supply. I would have to read the data sheet(s) on any other supplies you are speaking of.

Ron
 

bertus

Joined Apr 5, 2008
22,922
Hello,

Do you have links to datasheets of the mentioned power supplies?
A 1200 Watt power supply will give a max current of 20 Amps at 60 volts and will deliver 15 Volts at 80 Amps.

Bertus
 

ian field

Joined Oct 27, 2012
6,536
Watts = Volts * Amps

A power supply rated to deliver 60V @ 80 Amps is a 4,800 Watt supply. I would have to read the data sheet(s) on any other supplies you are speaking of.

Ron
Don't forget a small difference between input and output power.

A switcher should be 80% efficient at the very worst - but I doubt that would account for the difference the TS stated, unless one of them was linear.
 

Reloadron

Joined Jan 15, 2015
7,888
Don't forget a small difference between input and output power.

A switcher should be 80% efficient at the very worst - but I doubt that would account for the difference the TS stated, unless one of them was linear.
Yes, good point but I haven't a clue where the OP is getting his numbers. :) This is why I always ask for a data sheet, even one written in Chinglish.

Ron
 

crutschow

Joined Mar 14, 2008
38,503
It would seem that neither supply can deliver both the maximum current and maximum voltage at the same time.
Thus the power output (output voltage times the current) can't be more than its power rating.
 

ScottWang

Joined Aug 23, 2012
7,501
1. Vo=Wmax/Imax=1000W/50A=20V
It means that when you want to using the Imax 50A then you only can be use with 20V.
Because the Wmax is limited in 1000W, so you have to using Wmax to divide by Imax 50A.

2. Vo=Wmax/Imax==1200W/50A= 24V
It means that when you want to using the Imax 50A then you only can be use with 24V.
Because the Wmax is limited in 1200W, so you have to using Wmax to divide by Imax 50A.
 

Thread Starter

superway

Joined Oct 19, 2009
125
1. Vo=Wmax/Imax=1000W/50A=20V
It means that when you want to using the Imax 50A then you only can be use with 20V.
Because the Wmax is limited in 1000W, so you have to using Wmax to divide by Imax 50A.

2. Vo=Wmax/Imax==1200W/50A= 24V
It means that when you want to using the Imax 50A then you only can be use with 24V.
Because the Wmax is limited in 1200W, so you have to using Wmax to divide by Imax 50A.
Thanks. How about this model below; it is rated 60A, 85A, 51000W. That is W = 60 x 85 = 5100W. So It is different my previous screenshots ?
upload_2015-5-14_14-26-48.png
 

ScottWang

Joined Aug 23, 2012
7,501
Some power supplies was designed for the output by wattage, it means that the V/I output will be combined and limited by Watt, maybe this is the one.
 

mcgyvr

Joined Oct 15, 2009
5,394
It would seem that neither supply can deliver both the maximum current and maximum voltage at the same time.
Thus the power output (output voltage times the current) can't be more than its power rating.
Yep its UP to 60V and UP to 80A with UP to being important.. You just can't do both at the same time as its limited to how much power it can dissipate
You can really only do 20A @ 60V..(1200W) or 80A @ 15V (1200W) or any combination that doesn't exceed 1200W
 

ScottWang

Joined Aug 23, 2012
7,501
Th posted in #11 were used the max current, the similar when we using the max voltage then the current will be as these:

1. Io=Wmax/Vmax=1000W/60V=16.67A
It means that when you want to using the 60 Vmax then you only can be use 16.67A current.
Because the Wmax is limited in 1000W, so you have to using Wmax to divide by 60 Vmax.

2. Io=Wmax/Vmax==1200W/60V= 20A
It means that when you want to using the 60 Vmax then you only can be use 20A current.
Because the Wmax is limited in 1200W, so you have to using Wmax to divide by 60 Vmax.
 
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