Prevent screen from going to sleep

[Marco <netuse lavabit com>]

Hi everyone,

I have the problem that my  screen switches off after ten minutes. I
tried  to set  sleep-display-battery  to different  values, but  the
setting is not respected:

gsettings set org.gnome.settings-daemon.plugins.power sleep-display-battery 0

sleep-display-ac   doesn't  work,   either.   Other  settings   like
idle-dim-battery work perfectly.  I don't use a  screensaver. How to
keep the display turned on permanently?

Gnome 3.2.1

Marco