Efficient motors and controls for watercraft
AssigneeMaruta Electric Boatworks LLC
InventorMarvin A. Motsenbocker
Life of this patent
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Abstract
Electronic control systems, devices and algorithms are described for improving boat efficiency, safety and convenience, particularly for electric motor powered boats. The overall efficiency of electric boat propulsion is improved by matching the needs of the propeller with the magnetic field requirements of the motor. Efficiency also is improved by limiting slip at different boat speeds. Rapid and fully electronic propeller shut off systems also are described for enhancing public acceptance of electric boats and more convenient cruise control systems are described for improving public acceptance of the boating experience.
Claims37
An electronic control for enhancing the efficiency of an electric motor driven electric watercraft propeller drive comprising:
- a) a motor current measurement signal corresponding to propeller torque;
- b) a motor voltage measurement signal;
- and
- c) a comparator for monitoring the current and voltage signals,
- wherein the controller limits voltage to the motor upon sensing an overly high increase in motor current upon increasing motor voltage.
An electronic control device that controls propeller slip of an electric motor powered watercraft, comprising:
- a) a detector of propeller speed;
- b) a detector of the watercraft's speed, and
- b) a circuit that controls power to the armature of the motor, a field winding of the motor or both,
- wherein a signal from the detector actuates the circuit to adjust propeller slip according to a predetermined relationship between propeller and boat speed.
A simplified heading cruise control for a watercraft, comprising:
- a) one or more ratiometric output geomagnetic sensors mounted to the watercraft and that output one or more analog signals that correspond to geomagnetic heading;
- b) a circuit that analyses the signal(s) from the one or more geomagnetic sensor(s) to output one or more correction signals for altering course;
- and
- c) a maximum of one on/off switch on the watercraft required for activating the cruise control.
A non-mechanical electronic control system for inhibiting cavitation of a propeller driven electric powered watercraft, comprising:
- a) a boat speed monitor comprising a piezo electric transducer located at a surface of the boat hull in contact with water;
- and
- a) a control circuit,
- wherein the control circuit monitors motor voltage as an index of propeller speed and decreases motor power when the motor voltage is too high for a given boat speed.
A watercraft battery heat removal system for moving heat between a battery and water that the watercraft sits in, comprising:
- a) at least one battery with metal terminals;
- b) a heat conducting connector that physically contacts one or more of the battery terminals and receives heat from such one or more terminals;
- and
- c) a material that accepts heat from the heat conducting connector and transfers the heat to the body of water;
- wherein the one or more metal terminals contacts the heat conducting connector, the heat conducting connector contacts the material of c) and the material of c) contacts the body of water.
Dependencies are inferred from the claim text.