Duet 3 fan wiring question. 5v and 24v
bass4aj last edited by Phaedrux
I have both 24V and 5V fans that I need to connect to a Duet 3. On other duet boards, this was accomplished just by adjusting a jumper that either set voltage to V_IN or 5V. On the Duet 3, I am confused what the jumpers on the diagram are telling me. It seems like it can take voltage from either a 12V-36V power source, or 12V, but it doesn't seem able to drive 5V fans from what I can tell on the diagram. Currently, I am only powering the board with a single 24V power supply.
Can someone help explain how this works and correct my understanding? I would like to avoid frying anything through trial and error
bearer last edited by bearer
correct, you'd need to add a jumper wire from a 5v source to the
V_OUTLCnpin in question, or wire the positive lead of the fan directly to a 5v source.
hopefully we'll see a 3-way jumper adding 5v as an option in a future revision, this was my suggestion:
V_FUSED o V_OUTLCn o o 5V_EXT 12V_EXT o
The 12v regulator is nice, but I still kinda miss the V_fan pin.
bearer last edited by
but I still kinda miss the V_fan pin.
instructions unclear.. the V_OUTLCn pin is the equivalent of the V_fan pin is it not? Or do you mean the whole old Vin/V_fan/5V jumper. I think the rationale was more and more people will go for voltages above 12v and there is a limited selection of fans in 24v or more (12v fans are usually cheaper as well); but still we could have had it both ways.
bass4aj last edited by
Yeah, my main thing is I still use small 5V blowers for some cases, so its sad to see the 5V option gone... guess I will just need to use a buck reg. Thanks for the help.
bearer last edited by
guess I will just need to use a buck reg.
if you stay under 3A total for 5v and 3.3v you can just run a female-female jumper wire from a 5v pin over to V_OUTLCn, skipping the buck converter.
On Duet 3 we removed the built-in support for 5V fans, because we now provide a built-in regulator for 12V fans, and because a number of users have wrecked their Duets because of shorts between VIN and +5V in the fan wiring. I'm not aware of any good reason to use 5V fans rather than 12V fans, other than that you might have some already.