Patent ID: 8234724

Claim:
A system for controlling the flush volume of a flushometer, comprising: a dual flush valve associated with a waste receptacle fixture, the dual flush valve having a solid waste flush volume corresponding to a full flush volume and a liquid waste flush volume corresponding to a reduced flush volume; a presence detection sensor associated with the flush valve, the presence detection sensor configured to monitor for the presence of a user and provide a signal upon the detection of a user in a predefined area; an automatic flush control in communication with the presence detection sensor and the dual flush valve, the automatic flush control comprising a memory unit associated with the presence detection sensor and the flush valve, the memory unit having stored therein computer program instructions for: receiving the presence detection sensor signal; initiating a usage timer upon the detection of the user; stopping the usage timer upon no longer receiving a presence detection sensor signal; generating a usage time t x that equals time elapsed from initiation to stoppage of the usage timer when the user is no longer detected; modifying a usage cycle count N c by increasing N c by 1; determining if a number of cycles N c is less than a predetermined number of cycles N p ,; if N c <N p , then determining if the usage time t x is greater than or equal to a preset usage time value T p where if t x is greater than or equal to the preset value T p , then the flush valve is opened for the full volume flush, and if t x is less than the preset value T p , then the flush valve is opened for the reduced volume flush; if N c >N p , then determining if the usage time t x is greater than or equal to a calculated average usage time t p where if t x is greater than or equal to the calculated average usage time t p , then a full volume flush is performed, and if t x is less than the predetermined average usage time t p , then the reduced volume flush is performed; and modifying t p according to the value of t x , wherein the automatic flush control provides instructions actuating the dual flush valve for the solid waste flush volume or the liquid waste volume based on usage time.