I have an old PSU for an Fanhao D4X printer that has an output of 350 Watts (24 volt / 14.6 amps).
It’s no longer functioning but I do have another PSU that is the same in design except it produces 300 watts (12Volts / 25 Amps) which can be adjusted up to 350 Watts by increasing the voltage by 2.
Although the Wattage is the same will it damage the Wanaho MightyBoard as the voltage and amps are different?
Thanks for your help!
3DSmith
February 24, 2016, 5:32pm
2
In terms of damage, it’s the voltage that matters most. The voltages must be the same. The power supply with 300w may work just fine, or it may struggle, it depends how much power you printer needs. But the voltages must be the same to avoid damage. Tom
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In short if you bring 24v to the MightyBoard it won’t be damaged.
The damage might occur on the PSU as it might be pushing the limit of the amount of amps it can deliver at 24V.
12v * 25amps = 300W
24v * ?amps = 300W or 300/24 = 12.5
Now if the MightyBoard require more than 6.25 amps to power the printer over time the PSU will struggle or give signs of giving up maybe even burn!
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Thanks for the reply,
Just to clarify, the old PSU that no longer works was 24V / 14.6 Amps - 350 Watts
The new one that i’m potentially looking at putting in is 12V / 25 amps - 300 Watts, but it can be adjusted up to 14V bringing the Wattage back to 350, like the old PSU.
This new PSU would struggle to provide enough energy as it has half the voltage?
Thanks
On the contrary, the MightyBoard accepts any voltage input from 12v to 24v. In fact, I’ve yet to see a single 3D Printer board that doesn’t accept 12v, though some don’t like anything above 15v or so.
It’s entirely fine electrically to switch out the power supply to a 12v unit, since the Mightyboard accepts inputs of between 12v and 24v, but the problem may be in your heaters for both your bed and your hotends. Typically hotend heater cartridges dissipate 40W under whatever voltage they’re designed for (though 25W cartridges are also pretty common), so under 24v, the resistance is 24v^2/40W or 14.4 Ohms. Putting 12v through that reduces the power down to 12v^2/14.4 Ohms or just 10W, meaning you’d notice an approximately four-fold increase in heating times. This also goes for the heated bed. Using the same math, your typical 180W heated bed at 24v would be reduced to just 45W at 12v-nowhere near enough to even get the bed to a temperature suitable for ABS, let alone reach it in a timely manner. (Most of the heat would just be dissipated into the air.)
The heater cartridges are pretty easy: just buy a new set of 12v heater cartridges (they’re cheap and most are standard sized). The bed depends a lot on whether or not it’s dual powered, or capable of accepting both 12v and 24v inputs. If it is, then all you would need to do is resolder the bed wires to the proper ones for a 12v input. If not, you’d have to replace the bed entirely, which may not even be possible depending on whether or not a 12v bed exists for your model.
Hope this helped!
-Karl Zhao
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Short answer, don’t do this.
Nice explanation Karl, I will add that it might be cheaper to get a new 24V PSU instead as other component are 24V like the Fan who will also need replacing.
Karl below as given a good answer to why it will not work as great to do this. To help understand a bit more about electrical power read that quora answer https://www.quora.com/Whats-the-difference-between-amps-watts-and-volts
Well, it depends. If the bed is dual powered, then all you would need to buy is 2 heater cartridges ($5 bucks from China?) and a fan only if you can’t stand the old one being on 50% speed all the time. If the bed isn’t, then it’s almost certain that he’d spend way more than the cost of a new PSU since custom format heated beds are so freaking expensive.
Honestly though even if the bed were dual powered, in the same situation I would just get a new 24v PSU. Who knows what unexpected issues might pop up with 12v.
pheelan
February 26, 2016, 7:18am
11
Stuff designed to run from a 24v supply, will not work if you connect a 12v supply instead. You need 24v
