VCC and PS-ON in the RAMPS schematic

Hi,

i'm looking at the ramps 1.4 schemetic here and i have 2 questions:

first : i see all the +vcc points across the page but dosent see the wire that feeds that signal..
Only one that I can see is the vcc from the arduino but that cant be right ? the arduino dosent feed vcc to the rest of the ramps board ?
What is the VCC ? 5Volts or 12V ?

and second, If I want to install the PS-ON wire , do I need a simple 5V beside it or use the 5Vstb ?
and again, what is the VCC pins on that trio ?

thanks

Edited 1 time(s). Last edit at 10/08/2013 01:27PM by Rigor_M.

Regarding VCC.

The stepper motor drivers have two voltages. VMOT (the motor voltage) and VCC/VDD (the logic side, what it's called depends how it's labelled on the board).

The VMOT is fed directly from the 5A input on the RAMPS. This also feeds the VIN on the Arduino (via diode D1).

On the Arduino is a regulator that can provide enough power for the Arduino and other pieces. The VCC (usually 5V) from the Arduino powers all the logic side of the stepper controllers. These do not require a large amount of current.

There are a few ways to hook it up. If you want the Arduino always on you can remove Diode D1 and connect the 5Vstb to the VCC pin, and then connect the standby wire PS-ON.

The +5V pin is only to power servo motors. This is because a servo can draw a fair bit more current, so it's been given it's own input (so you don't have to run it off the Arduino).

I see.

Thanks for the info ;-)

J-F