Archives de catégorie : Alimentation


12V 360W power supply assembly

List of parts

  • 220V/110V – 12V 360W 30A power supply
  • Plastic cover +  LCD Voltmeter
  • IEC power connector + fuse holder and integrated switch
  • 3 x  M4x10 screws
  • 2 x M4x10 screws
  • 2 x M4 Nuts
  • 2 x 6cm black wires
  • 2 x 15cm black wires
  • 1 x 15cm green/yellow wires
  • [Not Provided] 1 cruciform screw diver

Préparation (vidéo)

Make sure the Power supply input power is compatible with your country, for example:

  • Europe : 220V
  • USA : 120V




Top Cover (vidéo)

Insert 2 M4x6mm screws inside the dedicated holes just next to the voltmeter LCD.
The screw head should be inside the cover letting the screw thread out of the cover.





Insert the power supply connector inside the dedicated hole and make sure the screws can go threw it.






Screw 2 M4 nuts on the M4 Screws thet goes out of the cover as shown on the picture.




Here is the inside view of the cover with the M4 screw heads that must be accessible with a screw diver in order to tight them up with their nuts.




Ground cable connection (vidéo)

Take the 15cm Yellow/Green cable and plug it on the side of the IEC connector the most inside the cover part.





Phases wires connection (vidéo)


Take the 2 small 6cm long phase wires (here with blue terminals), and connect them just next to the Ground wire (yellow/green).




Now connect the wire terminals on the connection pin on the same rows the same way as in the picture.
It’s more easy to connect them like the picture in a crossed over manner.


Connection of the last phases wires (vidéo)

Now take the 15 cm wires (here with red terminals) and connect them on the last 2 pins in the bottom row as shown in the picture:





Connection of the terminals on the power supply (vidéo)

Align the top cover as shown on the picture, with the power supply connector on the right side and the power supply terminals facing you.
You can also open the security cover on the power supply in order to have access to the terminals.



Ground wire connection (vidéo)

Connect the ground wire on the dedicated terminal on the power supply.

The corresponding terminal is the 3rd one starting from the right with the following symbol :





Here a zoom on the dedicated terminal







Phase wires connection (vidéo)

Now connect the 2 other phase wires on the terminals left on the right side of the power supply. Connect them on the terminals marked with « N » and « L » letters




Voltmeter connection

2 wires must be left, they are the ones of the Digital VoltMeter.
On the power supply side, you will find 6 free terminals.
They are separated in 2 groups:

  • +V
  • -V

The 3 terminals on the left of the power supply (the ones most outside of it) with the « +V » symbol correspond to the +12V output

You need to connect the Red wire from the digital Voltmeter to one of the +V terminals.
You can pick 1 of the 3 terminals on the left as you want.
The « Black » wire left will have to be connected on one of the 3 terminals on the certer of the power supply with the « -V » symbol
The following pictures show you how to proceed.

Zoom on the wires.






You can then close the security cover:







Output voltage tuning (vidéo)

This type of power supply allows to slightly adjust the output voltage using a small trim resistor and a screw diver.


In order to prevent you from any electrical hazard, we strongly recommend that you slightly close the cover before switching on the power supply. You might also consider having a quick access tuning trim (here on top of the picture.

  • Before switch the power on, make sure the Power switch is on the « 0 » position.
  • Also take a moment to check if a fuse is inserted inside the middle cavity (between the power switch and the power plug connector. You can remove the fuse cap with a small flat screw diver.The small chamber containing the fuse should be coming slowly.
  • Check that you have at least 1 fuse at the bottom of the chamber.
  • Push back the fuse cap in position.
  • Now, plug the power cable to the main power grid, and switch the power button on.





If everything goes well, the switch button should lit and the LCD voltmeter should show the current voltage output. here 12.4V. This value may vary for you, but you will tune it on the following steps so that you get 12.0







Take a screw diver and slowly turn it in one way and on the other way in order to align the power output to 12V.





Here is a zoomed picture on the trim resistor.




Once properly set you should have a stable 12.0V displayed on the LCD




Connection of the 12V output wires (vidéo)

  • Switch off thepower supply
  • Remove the power plug.
  • Take the 4 90cm long wires.

2 Wires  must have some Blue or black terminals and 2 other with red terminals .



Insert them into the front cover so that the terminals are inside the cover .
Also insert the other side of the wires having the red terminals inside the round holes with the « + » marking.
Regarding the wires with the blue terminals (or black), inser them inside the holes with  «  » marking.



All the terminals are inside the plastic cover.






The blue wires here have the Red terminals and the brown wires have the blue (or black) terminals






  • Now, connect the wires with the Red termials to the power supply terminals with the « +V » marking. They are mainly the one located on the left of the power supply just next to the green led.
  • The blue terminals wires should be left.Connect them on the free terminals on the power supply that should be around the middle with the « -v » marking


Closing of the cover (vidéo)

  • Push the plastic covert so that the side holes are aligned with the ones on the power supply .
    On one side you will need 1 M4 screw.
    On the other side you will need 2 of them




Fix the screws on their dedicated located.






Prepare the last 2 M4 screws on the other side of the cover.







Congratulation, your power supply is ready to be used.

12V 360W power supply installation

List of parts

  • Power supply unit 220V – 12V 360W 30A previously assembled (see this article)
  • 3 M6x12 screws
  • 3 M6 T-Nut
  • 2 M4x10mm screws
  • 1 power supply support
  • 1 side support
  • [provided] 1 allen key
  • [not provided ] 1 cruciform screw diver

Take the Power supply support that will maintain the PSU in place.

Prepare 2 set of screws/T-Nut on the 2 M6 holes.




Look for the 2 side screws that will be used to screw the support.





On one side of the power supply, you will find at the bottom only 1 screw hole and on the other side you will get 2.




Now take the 2 M4x10mm screws





Place the support the 2 holes on the support are aligned with the ones on the power supply




Start by inserting the first M4 screws so that you can  hold the support and the power supply together.





Now do the same for the 2nd screw





Slowly aligne the Power supply unit on the side of the vertical aluminum extrusion.

When the square holders of the vertical mounts are in front of you this should be on the left of the chassis as exposed on the picture.

You should be able to slide the T-Nuts inside the vertical slot of the extrusion.


Once inside the slot the power supply should be parallel to the vertical extrusion.





Align the top of the of the power supply with the top of the chassis. If you have followed the previous steps properly the IEC power plug and the power switch should be the closest of the chassis.




Now screw the M6 screw to hold the power supply in place.





The second screw is only here to secure the whole assembly.





Take the side support that allows to make sure the power supply stay still.

Prepare a set of screw/T-Nut as shown on the picture.




Screw it as high as possible inside the chassis . Here is touching the top square holder

The plastic is flexible enough, so you should find it easy  to place the plastic part around the power supply.

ATX power supply conversion for 3D printer usage

When choosing your power supply make sure you have enough 12V output current

To give you some general ideas, a standard 8″x8″ (22x22cm) heatbed will use something like 200 watts. This corresponds to nearly 16/17 amps .

Regarding the hot end you will need nearly 40w, and the electronics including the stepper motor will use nearly the same power.

So you need to have at least 90 watts (  about 8 amps) more only for this part.

The 3D printer electronics is often made so that it has 2 or more separate power inputs. One is dedicated to the heatbed and the other one is dedicated for what is left of the electronics.

So before using a ATX Power supply, it’s fundamental to check the 12V outputs.Here is a chart with the +12V1 and +12V2 that have at least 15 Amps each.

In our case we will use the 17Amps output to power the heatbed and the 15 amps one to power the other connector.

Most often the +12V1 and +12V2 are linked to 2 different kind of connectors.

The +12V1 is often linked to the 4 pin molex connectors that you can see at the bottom of the picture.

The +12V2 is often linked to the square 4 pin connector at the top of the picture. It’s him that power your computer CPU/motherboard.

If you have any doubt you should be able to get more details on the datasheet of your power supply.


Remove the square 4 pin connector with cutting pliers or with a strong pair of scissors.




Once cut you will have access to 4 wires: 2 yellow and 2 black.





Now take a 4 pin molex connector and cut it’s yellow and black wires from it.

You can keep the other wires on the connector . The red wire corresponds to a +5V and the black one to the ground wire (0V).

If you decide to cut the whole set of wire be very careful to insulate them with some electrical tape.


Once cut you should have something like in the picture.

Note that keeping the connector and the other wires attached prevent you from insulating the left over wires.




With your cutting tool, strip the black and yellow wires that you have just cut.




Now let’s look at the part that makes the ATX power supply start.

By default, when your PSU is connected to your computer and you press the « power » button, then the power is provided to the motherboard and other devices.

This is made on the very big plastic connector.

Take a trombone or a short wire a few centimeters.

Open the trombone entirely so that you can give it a U shape like on the picture.





The power supply is waiting for the Green wire to be connected to the ground (any black wire) in order to provide the full power to your devices.

On this connector you can have only 1 green wire.

Right next to it on the same row you will have 3 or 4 black wires linked to the ground.

Insert the trombone inside the connector in order to create a contact between the green and any black wire like in the picture.

If the trombone seems too big you can cut it shorter so it’s cleaner.




Here is an example of the trombone once cut.





On your electronic side, now take the green mobile connector from the Ramps board.

From top view you will get some marking telling you about the proper polarity of this connector with « + » and « -«  signs.

The « + » corresponds to the +12V so to the yellow wire and the « – » to the ground (0V) and black wire.

Take the wires from the 4 pin molex connector previously stripped and connect them to the most outside terminals. (here on top of the picture)

The ground wire (black) will have to be connected on the outside of the board (here at the very top)

The +12V will be connected just below.

Those 2 wires are powering directly the stepper motors as well as the electronics of your 3D printer.


Regarding the remaining wires, connect them on the 2 remaining green terminals.

Keep the same polarity as before, the black wire then the yellow wire on the left side of it.




Connect them 2 by 2 so the yellow together and the black wires together.

This last 2 terminals correspond to the heat bed power supply that will use most of the power.




This mobile connector, once plugged will allow you to easily manipulate your electronics, fix it and then care for the power cables later on..

WARNING: Check carefully that this connector is well plugged and that the opposite male pins are properly making contact with this connector.

In a few cases, if a bad connection is made, after a few hours of use, this connector may melt/burn causing the power connection to break and causing some failures on your heat bed not heating anymore or your electronics not starting anymore.

Check regularly that this connector is well plugged.