how can I connect my ramps 1.4 and arduino mega to my Laptop?

hello guys. I need to ask you on how to connect my ramps 1.4 &arduino mega to my laptop, because in the first time I fried my arduino and my ramps 1.4. can I plug the power to my arduino from my laptop and my ramps to the power supply  simultaneously?

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BharathK311 year ago

Hello im building a 3d printer. I have problem with how many volts and current of power supply i need to use for my printer.I tried using 12v 5amp Power Supply Unit but nothing is happening.Can anybody suggest me what voltage ratings of power supply i should use for my printer??????

Maximum Input Voltage

Power Supply without diode

There are three limiting factors to the maximum voltage that you can put into the RAMPS:

  1. The Arduino Mega maximum input voltage
  2. Filtering capacitor maximum voltages
  3. PTC fuse maximum voltages

First, the 1N4004 diode connects the RAMPS input voltage to the
Arduino Mega which has a recommended maximum input voltage of 12 volts.
If your board does not have this diode soldered in (or if you cut it),
you will need to power the Mega through the USB connector or through a
separate 5v line, but this allows a higher RAMPS voltage.

Second, most boards use 25v or 35v aluminum electrolytic
capactors (C2, C3, C4, C6, C7, C9, and C10). To be safe, you should only
go to half of your rated maximum voltage -- thus if your board has 35v
capacitors (code VZA) then you should use a maximum input of 17.5v.
The absolute maximum voltage is determined by the pololu servo drivers,
which themselves are limited to 35V.

Third, the MF-R500 (5A) PTC fuse is rated to 30V and the MF-R1100
(11A) PTC fuse is rated to 16V. They will need to be replaced with real

Power Supply with diode

If your board has a 1N4004 diode soldered in, do not apply more than
12 V to it. Original flavor Arduino Mega are rated to 12 V input. While
Arduino Mega 2560 can take 20 V, it is not recommended.

Did you ever explain how you blew it up last time ?

MAKE SURE the power is connected the right way round.

joee1 (author) 2 years ago

So, is it possible to work on repetier host while all motors and sensors are connected?? Another question, can I put any adapter from AC to DC (12 V) !! Without using the PC adapter?? Thank you in advance :)

If you check the specs: 6-16V DC for the external power supply of an Arduino.
You might want to do some reading on the Arduino hardware as all this is very well documented....

It is only a data connection over USB, on a powered USB port you can do a bit more but I see no way of frying an Arduino by connecting it to the computer.

The external power supply of the Arduino is to provide power for shields, sensors and everything attached to it and it is independent from the USB connection.