1.  Field of the Invention
The invention is related to the field of trash compactors and in particular to a system for automatically controlling the operation of a trash compactor. 
2.  Description of the Prior Art
The ever increasing volume of trash being generated has created the need for an effective and efficient method of disposal.  To this end, mobile trash containers have proven to be very effective for the removal of trash from factories, large buildings, apartment complexes, and other such facilities.  These mobile trash containers are placed in or near the factories or other facilities where they are filled by the local users.  The full trash containers are then periodically emptied or exchanged for an empty one by a hauler who transports the trash to a landfill, incinerator, or other designated disposal location.  This method of trash disposal has been optimized over a period of years by the use of trash compactors which compress the trash in the trash containers so that it can effectively hold more trash.  This factor substantially increases the time interval before the trash container must be emptied.  Since the major expense in the disposal of this trash is the cost of hauling the trash to the disposal site, it is obvious that the use of the trash compactors reduces the frequency at which the trash container must be emptied thereby optimizing the process. 
The proces can be further optimized if the hauling of part-full trash containers can be minimized.  Neumann, U.S. Pat.  No.  4,773,027, discloses an automated trash management system in which the compactor system is capable of measuring the fullness of each trash compactor by monitoring the fluid pressure applied to an hydraulic compactor.  The fullness of the trash container is calculated from the monotonically increasing portion of the monitored pressure.  The trash management system also includes a data transmission link between each trash compactor and a central location so that the hauler is constantly aware of the fullness of each trash container.  The emptying or removal of the full trash containers can then be scheduled, significantly improving the efficiency of the trash management system.