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Hi,

I’m looking for a power supply for my 3d printer and i don’t know what i should use.

I have 4 stepper motors each using 12v and 1.5 amps, a heat bed and an extruder which also use 12v but need a higher amperage for good heating, 4 L298n stepper drivers each using 5v, 4 L297 chips each using 5v. Which power supply should I get so that each of the appliances get the correct amount of power, and how should I do this. Can someone also please tell me how I should wire these appliances, and if i should do it in parallel or series.

Thanks a lot, Mitch

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I use a common computer power supply (ATX). It was cheap, probably around 450-500W.

Normally you’d plug all the things you mentioned into an electronics board like RAMPS which sits on top of an arduino mega.

plug everything into its place on RAMPS.

then connect power supply to the RAMPS board.

The bed is the most power-hungry component, often people use a relay and connect a seperate power supply from the mains to this (use with caution!).

google ramps 1.4 diagram for a picture

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Forgot to mention, some benefit of the ATX supply are:

- ability to turn on/off the power supply from your software over USB

- an abundance of 12v and 5v connectors

- ready made fans, fan controllers, lighting etc from the existing computer market. If you dont already have lots of fans, you’ll need them!

- lots of old computer cables from which you can salvage connectors and solder them onto any components which dont have power connectors.

downsides:

- can be quite big/bulky so can be hard to attach to, or hide within, your printers frame.

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Hi,

I would try with a PSU 12V 150-200W.

consider that you need 1.5A * 12V = 60W for the stepper motors. The chip power consumption is often a small portion (usually a hundred of milliwatts) of the total power so you can ignore it.

You have to consider the remaining power for getting the extruder and the bed and add it to the 60W to get the final correct power rate of your PSU.

remember 1Watt = 1 Amp * 1 Volt .

Just be sure to consider every possible dissipation in the previous equation and you’ll make a perfect balanced PSU.

I would than consider the idea to use a linear voltage regulator to drop the 12V to 5V and Give power supply to the integrated circuits.

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For printers running heated beds, I would recommend running a 24v compatible controller with a 350W 24v power supply. If you run 12v you will have trouble bringing your heated bed up to and maintaining temps required for prints to stick especially with an open printer. There are many good references on the RepRap wiki that will help you with wiring the PS to mains. When wiring Mains voltage please be careful and ensure that you fully understand what you are doing before you start.

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Can you send me a schematic of the connections? I am not using a ramps board only a bread board and I want to power everything using one power supply if possible is there a way?

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How can i set this up on a bread board? Its ok if i can’t control temperature but I want to set all of this up with one power supply. Supposing i use a 12v 15amp supply, how would i set it up so that the heating appliances get more current and the motors only get 1.5 amps?