Abstract: A system and method includes an aeration subsystem that excites enzymes in the liquid waste passing through the septic system. The aeration subsystem includes a compressor section that compresses the liquid waste and an injector section that injects oxygen into the compressed liquid waste. The system further includes a driver subsystem for driving the compressor section and a control subsystem for activating and deactivating the driver subsystem.

Abstract: Included herein is a system and method for controlling a velocity vector of an overhead crane. A motor is attached to the crane and is positioned to move the overhead crane and has an output vector including a rotational direction and a rotational speed. A variable frequency drive is positioned to transfer voltage and current at a frequency to the motor. A processing unit converts the output vector to an amount of voltage and current at a given frequency and can instruct the variable frequency drive to send a frequency to the motor at a frequency substantially equal to the frequency at which the motor is presently rotating. This creates a speed match for the motor reducing spikes during operation of the motor and substantially eliminates open circuit decay. A hydraulic brake operates in connection with the processing unit and the variable frequency drive to slow the crane without driving the motor into the brake.

Abstract: A crane apparatus is disclosed. A hoisting accessory is traversed by rotating rotating drums by driving of a traversing motor to take up or pay out wire ropes. Continuously variable transmissions are provided for changing rotational speeds of the rotating drums. A control device controls the continuously variable transmissions in a gear changing manner so that forces imposed on the drums by the wire ropes will be balanced. Thus, torques acting on the pair of drums are canceled out in all areas in which the hoisting accessory moves, whereby the capacity of the drive motor can be reduced.