Engraving machine with arduino
I need to send 20V to the inputs of my machine. How is it possible


You need some form of power supply for that. It is not possible to
send 20&nbsp;V from the Arduino directly.


  I know that my company does it without external power supply


Then you misunderstood something about either the electrical interface
of the machine, or about how your company connects it to the Arduino.

One possibility is that the machine inputs are 20&nbsp;V logic with
built-in pull-up resistors. This kind of input is normally meant to
be driven by an open collector output. If this is the case, then you
can drive those inputs from the Arduino through a transistor (either an
NPN or an N-channel MOSFET) with no external supply.

But this is only a guess. What you really need to do is read the
datasheet of the machine and see how those inputs are meant to be
driven, at the electrical level. It may be more efficient to find
someone at your company who knows already and can explain that to you.