Abstract: A drive system is provided for propelling a ship through water. The drive system has two propellers. The propellers are coaxial so that one propeller engages the incoming water first, and the other propeller engages the water after it passes through the first propeller. The drive system has a stator that causes a first rotor to rotate. The first rotor is connected to, the first propeller to cause the first propeller to rotate. The first rotor also causes a second rotor to rotate. The second rotor is connected to the second propeller to cause the second propeller to rotate.

Abstract: A system to control an asynchronous tri-phase motor where said system comprises: at least one filter directly coupled to the current of the Alternative Current (AC) line; a rectifier which rectifies the line current, a doubler which reduces the curl, elevates the voltage and delivers a voltage in Direct Current, a braking resistance which helps to dissipate energy when the system is in braking mode, a shunt resistance, which helps to measure the current which flows from the V-line between the doubler and the IGBT module, a source, which adapts the voltage which the microcontroller consumes and peripheries (operational amplifiers, detectors, etc.

Abstract: A single-phase to three-phase converter for starting and running a single, three-phase, load carrying induction motor having first, second and third Y-wound stator windings from a single phase power supply comprising a connector for connecting the input conductors to the converter to a source of single-phase alternating current, a connector for connecting the output conductors from the converter to the three-phase induction motor and adapted to connect one single-phase input conductor to the first stator winding and the other single-phase input conductor to the second stator winding, a bank of run capacitors connected between the first powered stator winding and the third unpowered stator winding to develop a voltage in the third winding at a phase angle different from the phase angles in the first and second powered windings, a potential-type relay comprising a set of normally closed contacts and a winding to open them, the windings connected between the second and third stator winding, a slave relay compris

Abstract: A rotary phase generator for generating 3 phase voltage is provided which can operate off of 230 or 460 volts A-C. Also provided is a rotary phase generator which has two groups of running capacitors for providing a stable voltage on the third phase at no load and light loads. In addition, a booster system is provided for a rotary phase generator to provide high starting torque to one or more of the motors operated on the rotary phase generator. A plurality of smaller rotary phase generators may be connected in parallel and started in time delay sequence to eliminate the heavy starting current when starting the system on one phase power.