Hi all,
Just about to start building my first Reprap (Prusia i3) and have ordered all my parts except the PSU as I was planning to use an existing computer ATX power supply. In my build I'm going to be using RAMPS 1.4 along with a MK2A heat bed.
I have a query with regards to using the ATX PSU.
Firstly, I want to note that I do not want to lop off all the unused connectors - quite happy to keep them as the plan is to use one or two lights and possibly run a raspberrypi along side for videoing the builds. For this reason I do not want to open the PSU. In fact, I dont actually plan on making a single permanent alternation to it.
With that said, on with the post :)
From what I understand the 'traditional' method is to short the PSU_ON pin (on the 24-port motherboard end) to cause the PSU to power up automatically.
You then take the square 4-pin 12v connector and merge the 2 grounds, and the 2 12 volts, then connect those up to the RAMP with the first 12 volt connection. Then you do the same with one of the molex ends to get power into RAMPS for the heat bed.
So the end result is two 12v connections going into the RAMPS, and I assume one is used to power the heat bed, the other powers everything else.
With that in mind, I wanted to ask a few questions as I'd like this build to be as nice and tidy as possible but without modifying the PSU in any way.
1) I planned on using a female 4-port end for the first 12v power supply, and modifying it to merge the 2 12v's and 2 grounds, then there would be the power and ground wire going from that to the RAMPS - sort of like a home made adaptor. Would this be ok, and is there any special wire/solder I need to be using here?
2) I want to do the same for the molex - run a female molex cable (taking only the 12v and ground) into the other 12v input on the RAMPS. Again, cable and solder limitations if any?
I did also want to ask one final thing which I did have a thought about:
3) Why is it not possible to just take BOTH 12v connections from the big 24pin ATX motherboard cable? Surely this way you have just one cable that can provide 3.3v, 5v and 12v. Is this possible? I was planning on eventually using a small breakout board with the 24-pin ATX female and mount it to my frame. So the PSU could theoretically just plug into that and provide all power, could it not?
Many thanks for your time and please forgive any massive stupidity on my part, the only electronics I've done is setting up a PIR on a RaspberryPi breakout board.
Just about to start building my first Reprap (Prusia i3) and have ordered all my parts except the PSU as I was planning to use an existing computer ATX power supply. In my build I'm going to be using RAMPS 1.4 along with a MK2A heat bed.
I have a query with regards to using the ATX PSU.
Firstly, I want to note that I do not want to lop off all the unused connectors - quite happy to keep them as the plan is to use one or two lights and possibly run a raspberrypi along side for videoing the builds. For this reason I do not want to open the PSU. In fact, I dont actually plan on making a single permanent alternation to it.
With that said, on with the post :)
From what I understand the 'traditional' method is to short the PSU_ON pin (on the 24-port motherboard end) to cause the PSU to power up automatically.
You then take the square 4-pin 12v connector and merge the 2 grounds, and the 2 12 volts, then connect those up to the RAMP with the first 12 volt connection. Then you do the same with one of the molex ends to get power into RAMPS for the heat bed.
So the end result is two 12v connections going into the RAMPS, and I assume one is used to power the heat bed, the other powers everything else.
With that in mind, I wanted to ask a few questions as I'd like this build to be as nice and tidy as possible but without modifying the PSU in any way.
1) I planned on using a female 4-port end for the first 12v power supply, and modifying it to merge the 2 12v's and 2 grounds, then there would be the power and ground wire going from that to the RAMPS - sort of like a home made adaptor. Would this be ok, and is there any special wire/solder I need to be using here?
2) I want to do the same for the molex - run a female molex cable (taking only the 12v and ground) into the other 12v input on the RAMPS. Again, cable and solder limitations if any?
I did also want to ask one final thing which I did have a thought about:
3) Why is it not possible to just take BOTH 12v connections from the big 24pin ATX motherboard cable? Surely this way you have just one cable that can provide 3.3v, 5v and 12v. Is this possible? I was planning on eventually using a small breakout board with the 24-pin ATX female and mount it to my frame. So the PSU could theoretically just plug into that and provide all power, could it not?
Many thanks for your time and please forgive any massive stupidity on my part, the only electronics I've done is setting up a PIR on a RaspberryPi breakout board.