  Maxwell's demons work by rectifying thermal fluctuations. They are not
expected to function at macroscopic scales where fluctuations become negligible
and dynamics become deterministic. We propose an electronic implementation of
an autonomous Maxwell's demon that indeed stops working in the regular
macroscopic limit as the dynamics becomes deterministic. However, we find that
if the power supplied to the demon is scaled up appropriately, the
deterministic limit is avoided and the demon continues to work. The price to
pay is a decreasing thermodynamic efficiency. Our work suggests that novel
strategies may be found in nonequilibrium settings to bring to the macroscale
non-trivial effects so far only observed at microscopic scales.
