Dear RepRap-community,
I am a beginner and started to build a prusa i3 at the beginning of this year. Currently, all the mechanical assembly and the electronics are finished for now, but there is still something that does not work. 8-)
I decided to use an atx psu to power the printer and more specifically I decided to go with the Lepa MX-F1 500W, since it was affordable and characterized with 34A on the 12V rail, which I thought were sufficient to run everything together (Datasheet to Lepa MX-F1).
To connect the psu with the electronics I proceeded as explained in the wiki (RepRap Wiki on PSU).
Everything worked fine with the new psu until I set the temperature of the heated bed in pronterface, what caused the psu to switch off, probably because of the build-in overcurrent protection. :S Then I got aware, that the psu seems to have two 12V rails, so I connected 4 yellow wires of one rail to the 11A-connection at the ramps board and two yellow cables from another rail (at least I think so) to the 5A-connection of the ramps board. But still the psu switches off when starting to heat the heated bed. ::o
In the attached pictures you can see that there are mainly 4 groups of yellow wires going out from the psu: 2x 4 yellow wires (with one yellow wire that goes to the molex-connectors), labeled as 12V2; and 1x3 yellow wires that are going to the molex-connectors and 2 single yellow wires that are probably labeled as 12V1 (probably, because the label is a little bit off to the right...).
[attachment 52080 12V_1.jpg][attachment 52081 12V_2.jpg]
So, I took 4 wires from 12V2 to power the 11A-connection on the ramps-board and the 2 single yellow wires of 12V1 to power the 5A-connection on the ramps-board.
EDIT: What I forgot to tell you is, that I am using 1,5 mm² speaker wire to connect the MK2B heated bed to the ramps-board.
Does someone have an idea of what I could have done wrong here? Do you think I have to use the wires, that are going to the molex-connectors? Or is the psu even not suited for this use?
Thank you very much for your input!
P.S.: I am sorry if I did something wrong or posted in the wrong section of the forum, since this is my first post. :)
I am a beginner and started to build a prusa i3 at the beginning of this year. Currently, all the mechanical assembly and the electronics are finished for now, but there is still something that does not work. 8-)
I decided to use an atx psu to power the printer and more specifically I decided to go with the Lepa MX-F1 500W, since it was affordable and characterized with 34A on the 12V rail, which I thought were sufficient to run everything together (Datasheet to Lepa MX-F1).
To connect the psu with the electronics I proceeded as explained in the wiki (RepRap Wiki on PSU).
Everything worked fine with the new psu until I set the temperature of the heated bed in pronterface, what caused the psu to switch off, probably because of the build-in overcurrent protection. :S Then I got aware, that the psu seems to have two 12V rails, so I connected 4 yellow wires of one rail to the 11A-connection at the ramps board and two yellow cables from another rail (at least I think so) to the 5A-connection of the ramps board. But still the psu switches off when starting to heat the heated bed. ::o
In the attached pictures you can see that there are mainly 4 groups of yellow wires going out from the psu: 2x 4 yellow wires (with one yellow wire that goes to the molex-connectors), labeled as 12V2; and 1x3 yellow wires that are going to the molex-connectors and 2 single yellow wires that are probably labeled as 12V1 (probably, because the label is a little bit off to the right...).
[attachment 52080 12V_1.jpg][attachment 52081 12V_2.jpg]
So, I took 4 wires from 12V2 to power the 11A-connection on the ramps-board and the 2 single yellow wires of 12V1 to power the 5A-connection on the ramps-board.
EDIT: What I forgot to tell you is, that I am using 1,5 mm² speaker wire to connect the MK2B heated bed to the ramps-board.
Does someone have an idea of what I could have done wrong here? Do you think I have to use the wires, that are going to the molex-connectors? Or is the psu even not suited for this use?
Thank you very much for your input!
P.S.: I am sorry if I did something wrong or posted in the wrong section of the forum, since this is my first post. :)