Prusa 8" i3 power supply?

Djmanmatt

Prusa 8" i3 power supply?
October 21, 2013 01:53AM

Registered: 11 years ago
Posts: 5

I just bought my first 3d printer Prusa i3 from MakerFarm and I was wanting know I have a pro power supply that outputs 13.8v 30a and 450w will this work.Iit only has 1 output. I know they recommend a ATX power supply just kinda wanted to use it. Thanks

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Jo1212

Re: Prusa 8" i3 power supply?
October 21, 2013 02:25AM

Registered: 12 years ago
Posts: 126

That sounds ok, other than the 13.8v instead of 12v? What do others think?

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vegasloki

Re: Prusa 8" i3 power supply?
October 21, 2013 04:45AM

Registered: 12 years ago
Posts: 661

That's probably a better choice if it's a quality power supply. A good quality single rail PSU will outperform an inexpensive ATX PSU.

If it's a Printrboard in the latest revision it shouldn't be an issue.

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Djmanmatt

Re: Prusa 8" i3 power supply?
October 21, 2013 10:43PM

Registered: 11 years ago
Posts: 5

Ok thanks. Now I was looking at the Ramps board and there is 2 inputs a 5amp and 11amp if I only have one output on my power supply were do I go do I bridge them?

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Jo1212

Re: Prusa 8" i3 power supply?
October 21, 2013 10:56PM

Registered: 12 years ago
Posts: 126

Correct me if I'm wrong, but the Ramps board can, at most, only handle 12v. And 13.8v wouldn't work.

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Djmanmatt

Re: Prusa 8" i3 power supply?
October 22, 2013 12:11AM

Registered: 11 years ago
Posts: 5

I did find this it seams it depends what kind of diode it has can very the voltage it can take. Wiki

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uncle_bob

Re: Prusa 8" i3 power supply?
October 22, 2013 09:41PM

Registered: 11 years ago
Posts: 1,433

The Ramps 1.4 board will handle a lot of voltage (like 35V). The Arduino Mega that's attached to the Ramps probably will get unhappy above 12 volts. It most certainly will die at anything approaching 20 volts.

------------------

The board will handle a lot of voltage.... The capacitors used on this or that build may or may not handle anythig over 16 volts. With derating that puts you into the "not a good idea" zone at about 14 volts.

Edited 1 time(s). Last edit at 10/23/2013 01:01PM by uncle_bob.

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vegasloki

Re: Prusa 8" i3 power supply?
October 22, 2013 09:59PM

Registered: 12 years ago
Posts: 661

My post was specific to the Printrboard but as noted there is a diode configuration that will allow RAMPS to operate at a higher voltage while providing the ATMega with the proper voltage. All the RAMPS I've used recently have the diode config though one should still check.

To connect the PSU I double stack hook up wire and run to each set of terminals on the board. They can be jumped at the terminal block but I find stacking the lugs at the PSU to be a cleaner solution and easier to implement.

Edited 2 time(s). Last edit at 10/22/2013 10:10PM by vegasloki.

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uncle_bob

Re: Prusa 8" i3 power supply?
October 23, 2013 11:51AM

Registered: 11 years ago
Posts: 1,433

On the standard Ramps 1.4 board there is a diode between the bulk power supply and the supply to the Mega board. If you remove that diode, the Mega can only be powered via USB. If you want a stand alone solution, you would need some sort of secondary regulator to take your "high voltage" power down to a more Mega friendly level.

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luigi

Re: Prusa 8" i3 power supply?
October 27, 2013 07:01AM

Registered: 12 years ago
Posts: 96

Meh,
Just be safe and get a 12v powersupply, they are only 30 bucks anyhow.

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uncle_bob

Re: Prusa 8" i3 power supply?
October 27, 2013 09:14AM

Registered: 11 years ago
Posts: 1,433

The MeanWell S-350-12 is a very nice 12V 29A supply. It's built in fan is quiet enough that you don't notice it over the noise of the printer.

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Jo1212

Re: Prusa 8" i3 power supply?
October 27, 2013 04:13PM

Registered: 12 years ago
Posts: 126

Yeah, I agree with luigi and uncle_bob...

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