Powering Ultimaker from 24VDC

[ianeagland 0]

Hi

I have a 24V DC power circuit in my workshop. Substantial batteries and PV panels. The voltage swings between 24V and 26.7 depending on the Sun and connected loads. So far it is running all my internet devices and some of the PC's. My aim is to run the Ultimaker from solar. Does any one know if the the Ultimaker PCB is capable of accepting say 27V DC as it is or will I have to construct a DC to DC power supply?

[Daid 306]

I think Joris ran his Ultimaker on 24V batteries as a test.

And I think it can be done, but remember that you'll supply both the motors and the heater with more voltage then default, so they work harder then normal. This might cause problems.

The 7812 on the board powers the electronics Fan and the Arduino, this one might get a bit hotter, so if you want to be really sure you could add a small cooling fin on it. (this component can take up to 30V, but the higher the input voltage the more hot it gets)

[mr_seeker 0]

Or just put a power resistor in between... Christmas lights should do

[Daid 306]

Or just put a power resistor in between... Christmas lights should do

Or stay away from electronics if you are not sure what you are doing.

[mr_seeker 0]

Or just put a power resistor in between... Christmas lights should do

Or stay away from electronics if you are not sure what you are doing.

I know what I am doing: Making sure that there is no "magic smoke" coming out of the machine

[Daid 306]

Or just put a power resistor in between... Christmas lights should do

Or stay away from electronics if you are not sure what you are doing.

I know what I am doing: Making sure that there is no "magic smoke" coming out of the machine

Are you doing that, or are you thinking you are doing that?

For example, your power resistor idea. That generates a normal resistor divider, but the resistance of the other side is far from stable, so the actual voltage behind the resistor will be unstable. Which is a good way to destroy electronics and get unreliable results.

The Christmas lights is even worse, because light bulbs do not have a stable resistance, they start out with a very low resistance on power on, and then quickly stabilize in 100ms. So every time you turn the machine on, you will have a lot more voltage on your board then intended.

[mr_seeker 0]

Bit goofing around

But I do know that the arduino can handle a max of 20V. So you need some sort of divider or voltage regulator to make sure that the arduino doesnt get a 24V kick...

[Daid 306]

The Arduino is not connected to the input voltage on a 1.5.4 PCB. And the design of the 1.5.6 is not online, but I think it was connected to the 12V regulator on those boards, but I could be wrong.

[ianeagland 0]

Many thanks for the replies.

I only just realised the board circuit designs are freely available so I can go through the circuit. I have some experience of adapting other devices to run off the nominal 24V. I have used dimension engineering (

http://www.dimensionengineering.com/products/de-swadj3

) to replace 78 series voltage regulators on a number of projects. They are expensive but they work and usually fit a PCB without any problem.