Power supply
Posted by hdoug5
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Power supply November 23, 2014 12:09PM |
Registered: 9 years ago Posts: 2 |
What is the maximum voltage that can be used on an i3 ? I have a 24 volt power supply that can be turned down to 15 volts but im not sure it will be safe to use
my nema 17 maximum voltage is 30 volts @3 amps I have no idea what the arduino board can handle or the ramps board any info will be appreciated
my nema 17 maximum voltage is 30 volts @3 amps I have no idea what the arduino board can handle or the ramps board any info will be appreciated
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Re: Power supply November 27, 2014 10:53PM |
Registered: 9 years ago Posts: 60 |
The RAMPS 1.4 is filled with components of varying max voltages. The D1 and D2 diodes on your RAMPS can only handle 12v on the 5amp rail. Personally I just use 12v off of a 500w power supply. If you're looking to heat your bed faster of your hot end a more powerful supply might help although 500w is more than enough. I would not go below 300w or 18amps with a heated bed. If you have a heated bed that will hugely up your current needs.Check your D1 and D2 diodes on the board first, these are 1N4004 diodes and they pass the electricity on to the Arduino. DO NOT put over 12v into the Arduino. If you must pass over 12v into your RAMPS get rid of the diode. If you do this you will have to power your Arduino with a separate power-supply or just a usb line. What I would recommend is a psu, I can find them at microcenter for $10 on clearance at 500w. Just use the yellow 12v line and you'll be good to go.
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Re: Power supply November 28, 2014 03:32AM |
Registered: 10 years ago Posts: 14,672 |
D1 and D2 are not a problem, they are 1N4004 types rated ar 400V. The Arduino Mega is rated at 20V maximum input voltage. The caveat is that the higher the input voltage, the higher the power dissipation in the voltage regulator. So the higher the input voltage, the less current you can draw from the 5V rail before the regulator goes into thermal shutdown. In a 3D printer, the only thing you are likely to connect to the 5V rail that takes much current is the backlight of an LCD, and you can avoid this by connecting the backlight through a suitable series resistor to the 12 to 20V input instead.
The other components on the RAMPS that could be limiting are the 100uF capacitors. The RAMPS wiki page unfortunately doesn't say what the voltage rating of these capacitors is. My guess is that they are either 25V or 35V types, but they could be as low as 16V.
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
The other components on the RAMPS that could be limiting are the 100uF capacitors. The RAMPS wiki page unfortunately doesn't say what the voltage rating of these capacitors is. My guess is that they are either 25V or 35V types, but they could be as low as 16V.
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
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Re: Power supply November 29, 2014 02:27AM |
Registered: 9 years ago Posts: 60 |
Putting over 12V through your Arduino runs the risk of overheating the power supply regulator and damaging the board. I would not recommend this.
I quote the wiki here "D1 should only be installed if the 5A rail is powered by 12V. It can be omitted and the Arduino will be powered from USB. You will want D1 installed if you add components to print without a PC. To reiterate, D1 MUST be omitted if you are powering the 5A rail by more than 12V, or the power is not absolutely clean, otherwise you may damage your ramps." I'm not sure who wrote the wiki but several places within the document seem to point out that 12V is a limit. I agree. Also, the RAMPS 1.4 fuses, one of which has a limit of 16v will be a problem (they can be replaced though). In the end your RAMPS 1.4 can be changed to accommodate higher voltages but in standard form 12V is where you need to be at. As for the caps they vary from who actually distributed the RAMPS but many are in fact 16V, don't go over unless you are sure b/c then they will explode.
I quote the wiki here "D1 should only be installed if the 5A rail is powered by 12V. It can be omitted and the Arduino will be powered from USB. You will want D1 installed if you add components to print without a PC. To reiterate, D1 MUST be omitted if you are powering the 5A rail by more than 12V, or the power is not absolutely clean, otherwise you may damage your ramps." I'm not sure who wrote the wiki but several places within the document seem to point out that 12V is a limit. I agree. Also, the RAMPS 1.4 fuses, one of which has a limit of 16v will be a problem (they can be replaced though). In the end your RAMPS 1.4 can be changed to accommodate higher voltages but in standard form 12V is where you need to be at. As for the caps they vary from who actually distributed the RAMPS but many are in fact 16V, don't go over unless you are sure b/c then they will explode.
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Re: Power supply November 29, 2014 03:43AM |
Registered: 10 years ago Posts: 14,672 |
Running the Arduino by itself from up to 20V is no problem. Unfortunately, many Arduino users run LED arrays, relays and sometimes even motors from the 5V rail, without understanding the effect on power dissipation in the regulator. It is to allow for some extra load on the 5V rail that the Arduino site quotes 20V maximum input voltage but 7 to 12V recommended. The RAMPS wiki is just blindly following that. As I said before, if you power an LCD control panel from the Arduino/RAMPS combo then you certainly do need to limit the input to about 12V.
So I don't think you need worry about feeding 15V to the regulator unless you are using an LCD control panel. OTOH I advise against using 15V if the capacitors on your RAMPS board are only rated at 16V.
Edited 1 time(s). Last edit at 11/29/2014 03:48AM by dc42.
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
So I don't think you need worry about feeding 15V to the regulator unless you are using an LCD control panel. OTOH I advise against using 15V if the capacitors on your RAMPS board are only rated at 16V.
Edited 1 time(s). Last edit at 11/29/2014 03:48AM by dc42.
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
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