CR-10 Mini bed (12v 220w) on Duet2Wifi

[jontek2]

I've got an Duet2Wifi i'd like to upgrade my old CR-10 mini with. The CR-10 has a bit unusual heated bed (305*235) and is 12V at 220W = 18,3 A.

Since this bed is uncommon size it's hard to find any 24V alternatives. I also prefer not to have an AC bed on this bedslinger.

On https://duet3d.dozuki.com/Wiki/Choosing_a_bed_heater it clearly states: "Direct from the Duet using 12V power. The Duet 2 (Wifi and Ethernet) is rated for up to 18A bed heater current, so this is suitable up to 12 * 18 = 216W power."

Could it handle the 18.3A on my CR-10 mini? If so i'd also need to replace the 15A Miniblade to a 20A, right?

Anything else?

[bricor]

Using an external MOSFET would be a better choice.

[dc42]

The fuse holder is in theory only rated to 15A but I think that's a UL rating and I don't think 18.3A would damage it. If you do connect the bed directly to the Duet, check that the fuse holder and the PCB traces connecting it don't get too hot.

[jontek2]

The MOSFET sounds like an great idea. I have an MKS Mosfet laying around.

So i guess this will move the load to the PSU rather than the Duet2Wifi.

How many AMPs will the Due2Wifi have while connected to a mosfet with the 12V 220W bed?

[Veti]

@jontek2 said in CR-10 Mini bed (12v 220w) on Duet2Wifi:

How many AMPs will the Due2Wifi have while connected to a mosfet with the 12V 220W bed?

what do you mean?
power usage of the duet? 2W.
see
https://duet3d.dozuki.com/Wiki/Choosing_the_power_supply

[jontek2]

For wiring the mosfet it would be:

PSU to Mosfet
Heated bed to Mosfet
Mosfet to Bed terminals on Duet2Wifi

So how much AMP, thru the bed terminals, would the Duet2Wifi have with a mosfet?

[Veti]

@jontek2

a few milli amps for the signal to the mosfet

[jontek2]

Alright, thanks!