Wireless power transmitter
First Claim
1. A wireless power transmitter, comprising:
- a resonant circuit, the resonant circuit including a transmit coil;
a transformer with a primary inductor and a secondary inductor connected to the resonant circuit, the primary inductor including a center tap, a first end tap, and a second end tap;
a switching circuit that alternately couples the first end tap and the second end tap to ground; and
a regulator coupled to the center tap, the regulator configured to control a power level of power transmitted by the transmit coil, in response to power requirements received from a wireless power receiver and errors detected in a current level of the primary inductor.
1 Assignment
0 Petitions
Accused Products
Abstract
A wireless power transmission system is presented. In some embodiments, a transmission unit includes a first inductor with a center tap, a first end tap, and a second end tap; a pre-regulator coupled to provide current to the center tap; a switching circuit coupled to the first end tap and the second end tap, the switching circuit alternately coupling the first end tap and the second end tap to ground at a frequency; and a resonant circuit magnetically coupled to the first inductor, the resonant circuit wirelessly transmitting power. In some embodiments, the switching circuit can be formed of FETs. The current provided to the center tap can be controlled in response to current sensors.
11 Citations
11 Claims
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1. A wireless power transmitter, comprising:
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a resonant circuit, the resonant circuit including a transmit coil; a transformer with a primary inductor and a secondary inductor connected to the resonant circuit, the primary inductor including a center tap, a first end tap, and a second end tap; a switching circuit that alternately couples the first end tap and the second end tap to ground; and a regulator coupled to the center tap, the regulator configured to control a power level of power transmitted by the transmit coil, in response to power requirements received from a wireless power receiver and errors detected in a current level of the primary inductor. - View Dependent Claims (2, 3)
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4. A wireless power transmitter, comprising:
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a resonant circuit, the resonant circuit including a transmit coil; a transformer with a primary inductor and a secondary inductor connected to the resonant circuit, the primary inductor including a center tap, a first end tap, and a second end tap; a switching circuit that alternately couples the first end tap and the second end tap to ground; and a regulator coupled to the center tap, the regulator configured to control a power level of power transmitted by the transmit coil, wherein the regulator comprises; a current error amplifier; a first current loop, the first current loop including a current amplifier that amplifies a difference between signals from a current sensor and provides a signal to the current error amplifier; a second current loop, the second current loop including a differential amplifier amplifying a signal from a current sensor and providing a second signal to the current error amplifier; a comparison pulse wave amplifier receiving an output signal from the current error amplifier and a ramp signal; and a driver that drives a transistor pair to supply power to an inductor capacitor pair while output of the current error amplifier exceeds the ramp signal. - View Dependent Claims (5)
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6. A wireless power transmitter, comprising:
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means for receiving power requirements and feedbacks from a wireless power receiver; means for controlling current coupled into a center tap of a primary inductor of a transformer to control a power transmitted to the wireless power receiver; means for sensing errors in controlling current, in response to the feedbacks from the wireless power receiver; means for switching outer ends of the primary inductor; and means for transmitting wireless power through a transmit coil inductively coupled to the primary inductor of the transformer. - View Dependent Claims (7)
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8. A method of transmitting wireless power comprising:
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coupling a transmit coil to a secondary inductor of a transformer; controlling current supplied to a center tap of a primary inductor of the transformer, in response to errors detected in a current level of the primary inductor; switching a first end tap of the primary inductor to ground at a frequency; and switching a second end tap of the primary inductor at the frequency such that the first end tap and the second end tap are alternately coupled to ground, wherein a power level of power transmitted by the transmit coil is controlled, in response to power requirements and feedbacks from a wireless power receiver. - View Dependent Claims (9, 10, 11)
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Specification