<p>The motors are powered from 12/24V external power supply, so the motors will not be powered. 
the ramps <a href="https://download.lulzbot.com/AO-100/hardware/electronics/RAMPS_1.4/RAMPS_1-4manual.pdf" rel="nofollow noreferrer">Schematics</a> shows the connection diagram and the power is provided via the VMot pin/12V.</p>

<p><a href="https://i.sstatic.net/n1tLn.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/n1tLn.png" alt="Stepper diagram"></a></p>

CC BY-SA 3.0
2018-04-09T12:29:28.110Z
Is it possible to select V in pin on arduino in place of 5 volt pin as logic power supply for motor driver?for how many drivers ,the 5 volt pin can be used as logic power supply on arduino?
sandeep kumar
CC BY-SA 4.0
2019-05-11T16:53:15.337Z
is possible, but you need a driver (switch) to change the source from 5V USB to External 9-24V.
Fernando Baltazar
CC BY-SA 3.0
2018-04-09T10:08:43.447Z
2018-04-09T10:08:43.447Z
profesor79
<p>I have a RAMPS 1.4 with Arduino Mega 2560 with 2 steppers connected to an external power supply using Polulo stepper drivers. The steppers are for X and Y axis movement. This external power supply is set to 12 volts and power is applied. I have configured the marlin firmware also.</p>

<p>Can I connect my setup to my PC using USB when the external power is also on?
If i connect the USB while the external power is off, do the motors take power from USB? Will this will burn my board?</p>

CC BY-SA 4.0
2019-05-11T16:51:09.910Z
Is possible that you can burn the USB port and or your steppers can't work due lack of power of the same port.
Fernando Baltazar
<ramps-1.4><stepper-driver><usb>
Can I use external stepper motor power and USB connection
sandeep kumar
# Can I use external stepper motor power and USB connection

(Asked by: username_0 on 2018-04-09)

I have a RAMPS 1.4 with Arduino Mega 2560 with 2 steppers connected to an external power supply using Polulo stepper drivers. The steppers are for X and Y axis movement. This external power supply is set to 12 volts and power is applied. I have configured the marlin firmware also.

Can I connect my setup to my PC using USB when the external power is also on?
If i connect the USB while the external power is off, do the motors take power from USB? Will this will burn my board?

**Tags:** ramps-1.4, stepper-driver, usb
> **Comments:**
> **username_1**: Is possible that you can burn the USB port and or your steppers can't work due lack of power of the same port.  

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## 1 answers

### Answer by username_2 on 2018-04-09. Score: 1 | Accepted answer

The motors are powered from 12/24V external power supply, so the motors will not be powered.
the ramps [Schematics](https://download.lulzbot.com/AO-100/hardware/electronics/RAMPS_1.4/RAMPS_1-4manual.pdf) shows the connection diagram and the power is provided via the VMot pin/12V.

[![Stepper diagram](https://i.sstatic.net/n1tLn.png)](https://i.sstatic.net/n1tLn.png)

> **Comments:**
> **username_0**: Is it possible to select V in pin on arduino in place of 5 volt pin as logic power supply for motor driver?for how many drivers ,the 5 volt pin can be used as logic power supply on arduino?  
> **username_1**: is possible, but you need a driver (switch) to change the source from 5V USB to External 9-24V.  

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