Patent ID: 8710704

Claim:
A performance venue comprising: a plurality of machines, each designed to move a load; a control center; a communication link coupling the control center to the machines; a machine switch coupled to the communication link and a corresponding machine, the machine switch movable between an open position and a closed position, the corresponding machine inoperable to move the load when the machine switch is in the open position and operable to move the load only when the machine switch is in the closed position; and a dead man circuit that draws a current that represents an actual mechanical load of the corresponding machine, the dead man circuit comprising: a switching element coupled to the machine switch that moves the machine switch to the closed position only when current in the dead man circuit is within a desired range; and a dead man trip that will open the dead man circuit when current in the dead man circuit is outside the desired range, which causes the machine switch to move to the open position.