Finding the right volts and amps for Ramps board

Hi guys,

So my question is fairly easy so I'll ask the question first then I'll go into detail below the question just in case my issue is something else

If you plug in a new power supply rated at 12v and 30amps to a ramps board, and start to see smoke appear from the ramps board on the positive and com entrance where the wires plug into, why is this happening? is there to much voltage that needs to be reduced or increased?

More Details

So I purchased a power supply for the Makerfarm Prusa i3 8, the new power supply is rated for 12v and 30 amps, here's more details (https://www.amazon.com/gp/product/B00D7CWSCG/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1), I connected everything (surge protector + Power Supply + Ramps Board and other stuff) and started to see smoke appear from the ramps board positive and com entrance on the ramps board. I heard the surge protector go off and I looked and saw the smoke appear, I quickly unplugged it and looked at the ramps board and everything looks okay but seems to me that there was either to much volts running through.

Before this I had a pc power supply cut the 12v connection and plugged it in and everything worked fine, I think it was running around 14 amps max, but I felt like it was a little weak (bed took sometime to heat up) but it did the job. I was messing around with it and I messed it up, therefore I went with purchasing a new power supply that I mentioned above.

After watching a few videos with multi meters, I really wanna get that part solved, what is the current amount of volts and amps you guys regulate if needed? there's a small dial to increase or decrease voltage, I might head to the store today to purchase a digital multimeter and check for a accurate 12v reading (tested on an analog it looks like its hitting 12v)

Thanks again guys for viewing this topic

Best Regards,

David O

A power supply will supply current (amps) as needed up to the capability of supply.

Things connected to power supply draw (suck) current

Something in your connection is shorted -- drawing maximum current (welder)
heating up --- letting out magic smoke.

If you put a current meter (amps) in positive line -- you will see you are pulling very high current
If you put a volt meter across the plus minus lines you will see voltage
---- voltage may go down drastically with out a supply that can compensate

Take some time -- learn what DC electricity is all about
you could prevent a fire or death?

[" target="_blank" rel="nofollow">learn.sparkfun.com]

I would guess you put +12 and gnd on the wrong pins and annihilated the reverse protection diode

12v 30amps is fine.

If you take a look at [reprap.org]
Along the bottom on the left you have the power plug, two polyfuses (one for the 5amp and one for the 11amp rail) and then the protection diode d2

Edited 1 time(s). Last edit at 04/23/2017 05:26PM by Dust.