  Energy exchanges under form of heat is neither the most natural or efficient
way to operate an engine in the quantum realm. Recently there have been in the
literature several proposals for "quantum measurement engines" where energy is
fed into the machine by operations which otherwise would be conducive to
quantum measurements on the working substance (henceforth "the system"). In the
analysis of the working of these devices, oftentimes it is assumed that the
only effect of measurement is to turn the state of the system from whatever
prior state to an eigenstate of the measured property, and energy exchanges are
determined therefrom. This ignores the intricacies of the quantum measurement
process. We propose a simple model of a quantum measurement engine where the
measurement process may be analyzed in detail, and therefore energy exchanges,
and limitations on their duration, may be traced more fully.
