Charger for hand-held rechargeable electric apparatus with switch for reduced magnetic field
First Claim
1. A system including a first electric circuit for transferring AC electric power to a second electric circuit which is mounted within a portable device such that the second electric circuit and the device are separable from the first electric circuit, wherein there is no electrical connection between the first electric circuit and the second electric circuit, wherein the first circuit comprises a first coil coupled around a first magnetic core wherein the first coil is coupled to receive an AC power signal for forming a magnetic field and wherein the second circuit comprises a second magnetic coil coupled around a second magnetic core for receiving the magnetic field, wherein the first magnetic core and the second magnetic core are substantially aligned for forming a completed magnetic circuit for reducing stray magnetic fluxes, the system further comprising means for deactivating the AC power signal to the first coil when the second magnetic core is removed from alignment wherein the means for deactivating comprises a circuit for detecting whether the second magnetic core is removed from alignment by monitoring a response to the AC power signal.
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Accused Products
Abstract
A system transfers electric power between two devices using a magnetic coupling and no electrical connections. Each device incorporates a magnetic core surrounded by a coil. When properly aligned the cores form a closed magnetic circuit whereby stray magnetic fluxes are substantially reduced. In the preferred embodiment, a base unit incorporates a substantially `C` shaped magnetic core surrounded by its respective coil. A portable detachable device, such as an electric toothbrush, incorporates a substantially linear shaped magnetic core surrounded by its coil. The linear shaped magnetic core and the portable device are configured to fit within a gap formed in the `C` shaped magnetic core forming a substantially closed magnetic circuit thereby. Stray magnetic fluxes are thus significantly reduced. Additionally, an apparatus deactivates the power to the coil in the base unit when the portable device is removed from the base unit or when the battery within the portable device is charged to a predetermined level.
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Citations
20 Claims
- 1. A system including a first electric circuit for transferring AC electric power to a second electric circuit which is mounted within a portable device such that the second electric circuit and the device are separable from the first electric circuit, wherein there is no electrical connection between the first electric circuit and the second electric circuit, wherein the first circuit comprises a first coil coupled around a first magnetic core wherein the first coil is coupled to receive an AC power signal for forming a magnetic field and wherein the second circuit comprises a second magnetic coil coupled around a second magnetic core for receiving the magnetic field, wherein the first magnetic core and the second magnetic core are substantially aligned for forming a completed magnetic circuit for reducing stray magnetic fluxes, the system further comprising means for deactivating the AC power signal to the first coil when the second magnetic core is removed from alignment wherein the means for deactivating comprises a circuit for detecting whether the second magnetic core is removed from alignment by monitoring a response to the AC power signal.
- 7. A system including a first electric circuit for transferring AC electric power to a second electric circuit which is mounted within a portable device such that the second electric circuit and the device are separable from the first electric circuit, wherein there is no electrical connection between the first electric circuit and the second electric circuit, wherein the first circuit comprises a first coil coupled around a first magnetic core wherein the first coil is coupled to receive an AC power signal for forming a magnetic field and wherein the second circuit comprises a second magnetic coil coupled around a second magnetic core for receiving the magnetic field, wherein the first magnetic core and the second magnetic core are substantially aligned for forming a completed magnetic circuit for reducing stray magnetic fluxes, wherein the second circuit further comprises a rectifier coupled to the coil and a battery coupled to the rectifier for storing power and further wherein the first circuit comprises a circuit for deactivating the AC power signal to the first coil when the battery is charged to a predetermined level wherein the circuit for deactivating comprises a circuit coupled to the battery for illuminating a LED when the battery is charged to a predetermined level and for extinguishing the LED when the battery is not charged to the predetermined level.
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14. A system including a first electric circuit for transferring AC electric power to a second electric circuit which is mounted within a portable device such that the second electric circuit and the device are separable from the first electric circuit, wherein there is no electrical connection between the first electric circuit and the second electric circuit, wherein the first circuit comprises a first coil coupled around a first magnetic core wherein the first coil is coupled to receive an AC power signal for forming a magnetic field and wherein the second circuit comprises a second magnetic coil coupled around a second magnetic core for receiving the magnetic field, wherein the first magnetic core and the second magnetic core are substantially aligned for forming a completed magnetic circuit for reducing stray magnetic fluxes, the system further comprising:
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a. means for sensing a level of current flowing in the first magnetic coil; b. means for comparing coupled to compare the level of current flowing in the first magnetic coil to a first reference level wherein the means for comparing forms a control signal wherein the control signal obtains a first control level when the level of current flowing in the first coil is less than the first reference level and wherein the control signal periodically transitions between the first control level and a second control level when the level of current flowing in the first magnetic coil is greater than the first reference level; c. an oscillator for forming an oscillator output signal coupled to receive the control signal wherein the oscillator output signal is enabled when the control signal obtains the first control level and wherein the oscillator output signal is disabled when the control signal obtains the second control level; and d. a switch for controlling the AC power signal to the first magnetic coil coupled to receive the oscillator output signal. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification