Meanwell UHP-1000-48
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it is the pot next to the output terminals, but the adjustable range is only 48~57.6V for the 48v model.
you can modify the power supply by changing some resistors in the feedback loop - i made thread a while back doing it to a 36v meanwell but obviously its not for the faint hearted or those who cares about warranties.
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Hi Martin,
as you already found out correctly, the internal potentiometer is only for fine tuning to adjust the output voltage in the arrea of 48~57.6V (+/- 1% tolerance).
as seen here:
However if you want to use the "programable output function" you have to apply external voltage on the intended pins. (manual page 4ff.)
However the manual tells you that it is only allowed to trimm the output voltage in the range of 50-120% of the 48V, so you cant go under 24V:
Follow the manual pages 4-7 to reach the voltage you need.
But no worries, if you need for example 12V, a step down (also known as buck converter) might fit your job
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Well....in general I don't like the idead to supply external power to change the output current. Why the hell this can't be done via a potentiometer?
I'm wondering what would be the better way. The former or using a buck converter to go down to 24V from 48V.
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maybe add another pot to the divide +12v-Aux into Pv input and set your 24v output? (missed that bit initially)
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Not sure what you exactly mean. Can you please explain that in detail?
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@MartinNYHC said in Meanwell UHP-1000-48:
Well....in general I don't like the idead to supply external power to change the output current. Why the hell this can't be done via a potentiometer?
What do you mean by "change the output current".
The current depends on the load.
You can adjust the voltage, as you have found, but only within the range the manufacture has provided for.
If you need a different voltage get a different unit.
Frederick
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I am usualy useing buck converters to step down from 24V to 12V or 5V. But you can also find step down converter that can handle 60-150 V (and more) input, depending on your needs. But also look in data sheet for the maximum power (watt) and ampere it can handle.
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@MartinNYHC said in Meanwell UHP-1000-48:
Not sure what you exactly mean. Can you please explain that in detail?
it says you can adjust the output by applying external voltage to Pv pin.
it also says it has a 12v/0.5a output that is always on on +12v-aux pin.
so if you connect a potentiometer between +12v-aux and gnd you will have a variable voltage on the wiper output of the potentiometer that you can set to the 2.5v that you need to connect to Pv pin to make the main output 24v?
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@bearer said in Meanwell UHP-1000-48:
@MartinNYHC said in Meanwell UHP-1000-48:
Not sure what you exactly mean. Can you please explain that in detail?
it says you can adjust the output by applying external voltage to Pv pin.
it also says it has a 12v/0.5a output that is always on on +12v-aux pin.
so if you connect a potentiometer between +12v-aux and gnd you will have a variable voltage on the wiper output of the potentiometer that you can set to the 2.5v that you need to connect to Pv pin to make the main output 24v?
Very good idea....thanks! So I don't need an additional PSU
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btw you'll probably still be limited to the max current of 21A
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@bearer said in Meanwell UHP-1000-48:
btw you'll probably still be limited to the max current of 21A
Yes, just saw that in the manual. 21A @24V is around 500W. I think that shold be sufficient ( at least for now). But who knows what comes in the future
When looking for buck converters they are far below 21A. So this would be no option.Should I try to sell the PSU and get a new 24V one? I'm not quite sure yet....
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I'm guessing if you need more than 21A you'd likely be able to use multiple power supplies across multiple expansion boards or split the supply for the heated bed as it has its own input.
If 21A wasn't sufficient my frst move would be mains powered heaters.
(unless you have 24v fans you could also increase the voltage towards 32v and limit the duty cycle for the heaters within reason taking note of the high powered heater warnings if you get any)
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I decided to go with a new PSU. Don't want to start the new build with workarounds
Thanks for your help guys!
