Hi there,
I’m new to this forum so I hope that my post landed in the right category…
Just bought the NANO V3.1 board but I just miss some information… was going to Nano info @github,
It seems that this information is old… are I’m looking att the correct place?
I’m looking for the max power out for HE0, HE1 and H-BED, any clue where I can find it?
TIA for the help
Back again, after reading the schematic and check the board, it have HY3403V MOSFET, according to the datasheet it have a “Maximum Power Dissipation: 60 W”…
And if I remember and calculate correct it will give 12V 5A (=60W) for each channel, correct?
That’s not the “max power out” though. You do not want your MOSFET dissipating as much heat as your hot end or heated bed!
The capacity limit you are looking for is amps.
The datasheet I see has almost no information (e.g. no characteristic curves), but does say it is rated 30V 100A and Rds(on) of 2.9mΩ(typ.) @VGS = 4.5V. It’s probably a little higher at 3.3V that I think is used on that board, probably still under 4mΩ. But it means that when you use Ohm’s law to calculate the heat it will dissipate in use, you can treat it as a .004Ω resistor and be conservative.
Besides your wiring and power supply, I expect your limiting factor will be the board design; things like the size of the traces and the connectors in use, board design for dissipating heat. (Some of it depends on you not MKS. If you clamp those screw terminals down on bare wires, they may break and before they break might become a hot spot, so you really want to use crimp ferrules.)
I don’t see any information on that site about capacity for those three terminals. You’ll have to ask MKS about their design capacity.
Thank you for a quick reply, I will reach out to MKS…
Just to be sure I have ordered “Heated bed mosfet PCB” (based on NCEP01T18T) for my hot ends and SSR for the heated bed that will be in 230V.
…and for sure I will be using crimp ferrules in the connectors.
Since you don’t need any of the total thermal capacity of your board for the bed heater, you have even more overhead available for the hot ends. Even without that, I’d be quite surprised if you need off-board MOSFETs for the hot ends.
Because the Rds(on) is so much smaller than the resistance of the hot end, we can ignore it for purposes of knowing current; it’s orders of magnitude less than the resistance in your hot end. Therefore we can use your 12V 5A starting point without having to recalculate with both resistances in the circuit. For your 5A at 12V hot end you mentioned:
0.004Ω * 5A² = 0.1W
That’s going to be well within the thermal capability for your board, I’m sure. In fact, even if you had 25A going to a heated bed, that would still be only 2.5W dissipated by the MOSFET, because 0.004Ω * 25A² = 2.5W.