Non 12/24V power supply

kunok

Can you confirm me if I will be able to user for example a typical 19.5 V laptop supply? I know that I will need to recalculate the power of the thermal elements and the steppers.

Also as a suggestion for future boards, they should be compatible with USB C PD, a regular USB C 60, 80 or 100 W power supply in 20V mode will be able to power a 3d printer, they are very easy to source and they are standard elements.

DocTrucker

Need to know more about your machine including heater powers and laptop PSU current limit.

Most machines consume more than 100W on the heater bed alone, and would need more power for steppers, electronics, and hot end heaters - particually during warm up.

Minimum PSU size for a well specified 200mm cube printer would likely be in the 200-300W range.

kunok

Mains connected heated bed with a SSR, or maybe no heated bed at all. 30W 24 V hotend heater, that would be 24.37W using 19,5 V. I'm only talking about the voltages. I understand the current limitations of the board and I'm working with them in mind.
I'm pretty much against using the heating elements with anything that is not main power, I can understand in the extruder hotend, but in the bed I just don't see the point.
This will be for a very small, low power printer.

DocTrucker

Voltage limits for VIN covered in the manual:

https://duet3d.dozuki.com/Wiki/Choosing_the_power_supply

With regards other power supply types two screw terminals is about as generic as you can get. Chassis mount another socket if you want to use a specific power supply.

resam

@kunok keep in mind that fans and possible Z probes need to work at the same voltage, unless you explicitly select a different voltage source via jumpers or other methods.

Apart from that - you can supply any voltage you want, given they are within the Duet board specs (min and max).
Current (or Wattage) is of course the next question you need to keep in mind.

A Former User

Not sure all laptop chargers are designed for continuous full load though, most will only ever see full load when charging an empty battery while machine is running at full load, which would be 1-2 hours or so. I'd keep an eye on the temperature of the supply the first few prints.

But apart from that, if you have enough supply current, and the reduced heat from a 24v heater is sufficient then sure.

dc42

Yes you can use 19V power. The RepRap Huxley printer does that, so does the Fisher I think. Btw, RepRap Ltd. sells a 19V blower fan.

Last time we looked at using a USB C connector on the Duet, they were too expensive.

willpuckett

I've been happily using usb c pd to run my printer on 20v. I'm currently configured for a LDM extruder so no hot end, and the steppers and electronics are running at about 20 watts including some lights. Noctua makes PWM versions of most of their fans in 5v, so I've been using those to avoid having to do a 12 or 24 v circuit. That all seems well within the range and duty cycle of a good 90 or 100w GaN usb c power supply.

Functionally, it doesn't really achieve anything that having the larger power supply didn't, but being able to find a screw when I drop it in the case and reducing the wiring clutter I had before was worth all the work!

Even when I had the hot end on, I never used the bed heater. It seems a lot greener to just use a little glue stick and my prints came out better.