In today’s patent we see that Apple is exploring ways of building a miniature electromagnetic induction system right into future portable devices as a means of extending battery life. This is one race Apple can’t afford to lose.
Apple’s patent is all about systems for harnessing power through electromagnetic induction utilizing printed coils. A system could include one or more moveable magnets adjacent to printed coils on a circuit. For example, a system could include one or more magnets that are operative to move alongside a circuit board that includes printed coils. The one or more magnets may move, for example, when a user shakes the system or when the user walks or runs while holding the device. The movement of the one or more magnets may create an electromotive force (e.g., a voltage) across the printed coils, and this force may be used to generate electric power.
An electromagnetic induction system could include power storage circuitry for storing power harnessed by the system. An electromagnetic induction system could also include application circuitry for using power harnessed by the system.
The targeted devices for Apple’s proposed electromagnetic induction system include the iPod, iPod touch, iPhone, MacBooks.
Printed coils could be formed using any suitable technique for printing circuit boards. For example, printed coils could be formed by depositing copper on a substrate to form traces in the shape of coils or selectively etching copper from a substrate to form traces in the shape of coils. In some embodiments, a circuit board may include multiple layers and printed coils could be formed on two or more of the layers. In such embodiments, the coils may be electrically coupled using vias to create a coil array. In some embodiments, multiple circuit boards with printed coils may form stacks of circuit boards that are electrically coupled together to form a coil array.
In Apple’s patent the circuit board could include multiple layers. Each layer of the circuit board could include a conductive trace forming a coil for electromagnetic induction. In patent we see a layer of a circuit board that could include multiple printed coils adjacent to each other.
According to Apple’s patent, one or more moveable magnets may be used to harness power through electromagnetic induction. For example, a system may include a single magnet adjacent to one side of a coil array. In another example, a system may include a first magnet adjacent to a side of a coil array and a second magnet adjacent to an opposite side of the coil array. The two magnets may move freely alongside the printed coils or they may be coupled together so that they move in unison.
Apple’s patent include, respectively, electromagnetic induction systems 800 and 900 which may include a coil array and a moveable magnet. In some embodiments, an electromagnetic induction system could include multiple moveable magnets adjacent to printed coils, at least two of which could be on different sides of the printed coils. It may be advantageous to position magnets on opposite sides of printed coils so that opposite poles face each other because such a configuration may cause the magnetic field to extend through the coils in a relatively straight line that is perpendicular to the coils.