A system and method for variable power transfer in an inductive charging or power system. In accordance with an embodiment the system comprises a pad or similar base unit that contains a primary, which creates an alternating magnetic field. A receiver comprises a means for receiving the energy from the alternating magnetic field from the pad and transferring it to a mobile device, battery, or other device. In accordance with various embodiments, additional features can be incorporated into the system to provide greater power transfer efficiency, and to allow the system to be easily modified for applications that have different power requirements. These include variations in the material used to manufacture the primary and/or the receiver coils; modified circuit designs to be used on the primary and/or receiver side; and additional circuits and components that perform specialized tasks, such as mobile device or battery identification, and automatic voltage or power-setting for different devices or batteries.

System and method for inductive charging of portable devices

A portable inductive power source, power device, or unit, for use in powering or charging electrical, electronic, battery-operated, mobile, and other devices is disclosed herein. In accordance with an embodiment the system comprises a pad or similar base unit that contains a primary, which creates an alternating magnetic field by means of applying an alternating current to a winding, coil, or any type of current carrying wire. A receiver comprises a means for receiving the energy from the alternating magnetic field from the pad and transferring it to a mobile or other device. In some embodiments the receiver can also comprise electronic components or logic to set the voltage and current to the appropriate levels required by the mobile device, or to communicate information or data to and from the pad. Embodiments may also incorporate efficiency measures that improve the efficiency of power transfer between the charger and receiver.

Inductive power source and charging system

A power source, charging system, and inductive receiver for mobile devices. A pad or similar base unit comprises a primary, which creates a magnetic field by applying an alternating current to a winding, coil, or any type of current carrying wire. A receiver comprises a means for receiving the energy from the alternating magnetic field and transferring it to a mobile or other device. The receiver can also comprise electronic components or logic to set the voltage and current to the appropriate levels required by the mobile device, or to communicate information or data to and from the pad. The system may also incorporate efficiency measures that improve the efficiency of power transfer between the charger and receiver.

Power source, charging system, and inductive receiver for mobile devices

Systems and methods for enabling efficient wireless power transfer, and charging of devices and batteries, in a manner that allows freedom of placement of the devices or batteries in one or multiple (e.g., one, two or three) dimensions. In accordance with various embodiments, applications include inductive or magnetic charging and power, and wireless powering or charging of, e.g., mobile, electronic, electric, lighting, batteries, power tools, kitchen, military, medical or dental, industrial applications, vehicles, trains, or other devices or products. In accordance with various embodiments, the systems and methods can also be generally applied, e.g., to power supplies or other power sources or charging systems, such as systems for transfer of wireless power to a mobile, electronic or electric device, vehicle, or other product.

Systems and methods for wireless power transfer

Roadway-powered electric vehicles (RPEVs) are attractive candidates for future transportation because they do not rely on large and heavy batteries but directly and efficiently get power while moving along a road. The inductive power transfer systems (IPTSs) that have been widely used for the wireless powering of RPEVs are reviewed in this paper. The development history of the IPTS is tracked from the origin of the RPEV in the 1890s to the recent RPEV. Throughout its 100-year history, the size, weight, efficiency, air gap, lateral tolerance, electromagnetic force, and cost of the IPTS have been substantially improved, and now RPEVs are becoming more widely commercialized. Important milestones of the developments of the IPTS and RPEVs are summarized in this paper, focusing on recent developments of on-line electric vehicles that were first commercialized in 2013.

Advances in Wireless Power Transfer Systems for Roadway-Powered Electric Vehicles

A constant voltage inductive power coupling for magnetically transferring electrical power from a power source through an air gap to a load comprising a first electromagnetic inductor connected to a power source to generate a shaped alternating magnetic field, a said inductor with a saturable core separated by an air gap from the first inductor and magnetically coupled thereto to receive the shaped magnetic field, the core being responsive to the field to enter a state of magnetic saturation. A coil is electromagnetically coupled to the saturable core and has output leads connected to the load. A capacitor is in electrical communication with the coil to form a tuned circuit that is below resonance at the coupling operating frequency. The magnetic field induced by the first inductor to the second inductor causes voltage in the coil, whose magnitude is determined by the amount of magnetic flux in the core. The saturable core is responsive to any change in input voltage to magnetically counteract such change so as to maintain the core in its state of saturation thereby tending to keep the output voltage constant. Also any increase in load current is associated with a closer approach of the tuned circuit to a resonant condition tending to maintain the output voltage at a constant level. The invention is particularly useful in battery charging circuits or for other applications where the voltage required must be kept at a constant level.

Inductive power coupling with constant voltage output

An automatic guidance device for an electrically driven vehicle inductively coupled by a power receiver core to a roadway core connected to power source. The device which is attached to the power receiver core or to a ferrous bar connected to the underside of the vehicle comprises at least two sensor coils equally spaced from the midpoint of the power receiver core which is on the vehicle centerline. End portions of the vehicle core or bar which extend beyond the coils comprises magnetic poles which receive flux from the roadway inductor. Flux through the coils produces voltages which vary in proportion to their distance from the roadway inductor centerline and are compared to produce error signals used to control a steering servo on the vehicle. In event of roadway power failure a circuit is provided to enable the utilization of battery power to produce sufficient flux to maintain the production of error signals and thus steering control.

Lung Sheung Brian Ng

Papers

Inductive power coupling with constant voltage output

Guidance system for inductively coupled electric vehicles

Induktive Energiekupplung mit konstantem Spannungsausgang