Multiple power supplies 12/24

Danal

Exactly what @gtj0 said.

Swap 12V PSU to 24V, add buck for fans that feeds the + to the fans, and the fan - is to the duet to be switched... and replace hot end heaters with 24V.

What about your bed?

clearlynotstef

@Danal Bed is 120v on SR. Is there a reason to use a buck converter when I already will have a spare 12v power supply? Couldn't I just add a 24v to the duet for motors, and connect the + fans to the current 12v power supply for power directly? then just the ground to the board for pwm/switching?

gtj0

@clearlynotstef Sure. You're the one that mentioned the converters.

Danal

While I believe that would work... inexpensive power supplies are notoriously weird about their ground (internally). May or may not be tied to earth ground, may or may not be a true zero potential, etc.

Personally, I'd be MUCH more comfortable with the converters on the fans.

clearlynotstef

Alright so let's say I go buck converters for the fans then, new carts for the hotend heaters, bed is SSR so nothing there, and by the time I'm done there will likely be 7 nema 17s, one of which is a little baby pancake on the extruder. 360 watt should do?

Danal

How many hot ends on at once?

Phaedrux

https://duet3d.dozuki.com/Wiki/Connecting_and_configuring_fans#Section_Using_12V_fans_when_VIN_is_24V for buck converter example.

https://duet3d.dozuki.com/Wiki/Choosing_the_power_supply for some guidance on wattage requirements.

clearlynotstef

@Danal Just one, swappable smart effectors, one with a .4 v6 and the other with a volcano with a .8 (and a bigger heater).

logriso

Hi there.
i did what 's written in the article posted from @Phaedrux ...the only difference is that my 12V p.s. is coming from a dedicated 12v power supply. (i don't this this is matter)
I followed the instruction but my fan doesn't work. it works only when i connect internal 5V by jumper. (obviously less then full speed).
anyone has an ideas?

thanks

Danal

There are 3 options in that article. Which one did you use?

And can you post photos of the wiring of the buck converter?

logriso

@Danal , I used the article only to have the information for connection of 12V in the middle pin of voltage selection for fan. (V_FAN_A)
I didn't used a buck convertor, but a power supply already used to other equipment.
I connected the DC 12V+ from power supply following the indication of attached picture.
My 12V p.s. is directly supplied from 220 V .
I dont think that the 12 V to supply the fan has to be derivated from the duet board....but i'm not sure....
the result is that my fan doesn't work in this configuration.

Bye

Danal

What you show for the converter should work. Assuming the screw was adjusted so it outputs 12V

Edit: Board wiring looks correct.

Double check that converter is outputting 12V