Abstract: According to examples, a charging interface for a wearable device may include a receiver coil arranged inside the wearable device; a transmitter coil arranged outside the wearable device, where the transmitter coil is to generate a charging voltage for the wearable device via magnetic induction with the receiver coil. The charging interface may include a first pair of magnets having respective polarity axes and positioned at top and bottom portions of the transmitter coil, and a second pair of magnets having respective polarity axes and positioned at top and bottom portions of the receiver coil. The polarity axes to may be aligned with an attachment plane between the transmitter coil and the receiver coil. Furthermore, the polarity axes of the first pair of magnets may be reversed with respect to corresponding second pair of magnets.

Abstract: A power management system for a display light emitting diode (LED) driver for an augmented reality/virtual reality (AR/VR) device mitigates (e.g., attenuates) an input peak power delivered to the LED driver from a DC source and decreases a voltage ramp rate of the LED driver while maintaining the default current ramp rate or vice versa. A liquid crystal on silicon (LCOS) digital process is used to provide a current reference with a slow ramp rate and/or to provide an offset. The offset (e.g., a delay) may be implemented between the voltage ramp and the current ramp to achieve a non-overlapping output voltage and output current.

Abstract: A disclosed electronic device may include a battery and a battery enclosure member securing the battery. The battery enclosure member may have a polymer base layer and a metal coating covering at least a portion of a surface of the polymer base layer. A method for manufacturing a battery enclosure member may include 1) providing a polymer base layer dimensioned to abut a battery in an electronic device, 2) etching a surface of a polymer base layer, and 3) depositing a metal coating over at least a portion of the surface of the polymer base layer. Various other methods, systems, and devices are also disclosed.

Abstract: A high frequency, high efficiency, near field wireless charging system and interface for battery-powered wearable devices are provided. A number of various magnetic core, multi-winding transmitter coil, receiver coil configurations may be used with the transmitter coils generating a charge voltage at the receiver coils through magnetic flux. In some configurations, a buck-boost assisted transmitter, or a buck-boost split between transmitter and receiver charging system may be used. In other configurations, a switch-cap boost block on the transmitter side may be used to increase efficiency. In yet other configurations, a dual path charging system (e.g., for smart glass temples) or a dual transmitter—single receiver charging system with buck-boost or switch-cap blocks may be used. The transmitter-receiver pair configurations may also be used to charge a battery module to be inserted into a wearable device.

Abstract: A multi-cell battery powered device can include at least one power input, a first power converter coupled between the power input and a battery bus, a second power converter coupled between the battery bus and a system load of the electronic device, a plurality of cells, and a plurality of primary battery protection switches. The primary battery protection switches can be selectively operable to couple the plurality of cells in: (1) a parallel configuration in which the cells are coupled to the battery bus so as to charge or discharge in parallel, (2) a series configuration in which the cells are coupled to the battery bus so as to charge or discharge in series, and (3) an isolated configuration in which at least one of the plurality of cells is coupled to the battery bus and at least one of the plurality of cells is disconnected from the battery bus.

Abstract: A high frequency, high efficiency, near field wireless charging system and interface for battery-powered wearable devices are provided. A number of various magnetic core, multi-winding transmitter coil, receiver coil configurations may be used with the transmitter coils generating a charge voltage at the receiver coils through magnetic flux. In some configurations, a buck-boost assisted transmitter, or a buck-boost split between transmitter and receiver charging system may be used. In other configurations, a switch-cap boost block on the transmitter side may be used to increase efficiency. In yet other configurations, a dual path charging system (e.g., for smart glass temples) or a dual transmitter—single receiver charging system with buck-boost or switch-cap blocks may be used. The transmitter-receiver pair configurations may also be used to charge a battery module to be inserted into a wearable device.

Abstract: According to examples, a charging interface for a wearable device may include a receiver coil arranged inside the wearable device; a transmitter coil arranged outside the wearable device, where the transmitter coil is to generate a charging voltage for the wearable device via magnetic induction with the receiver coil. The charging interface may include a first pair of magnets having respective polarity axes and positioned at top and bottom portions of the transmitter coil, and a second pair of magnets having respective polarity axes and positioned at top and bottom portions of the receiver coil. The polarity axes to may be aligned with an attachment plane between the transmitter coil and the receiver coil. Furthermore, the polarity axes of the first pair of magnets may be reversed with respect to corresponding second pair of magnets.

Abstract: A multi-cell battery powered device can include at least one power input, a first power converter coupled between the power input and a battery bus, a second power converter coupled between the battery bus and a system load of the electronic device, a plurality of cells, and a plurality of primary battery protection switches. The primary battery protection switches can be selectively operable to couple the plurality of cells in: (1) a parallel configuration in which the cells are coupled to the battery bus so as to charge or discharge in parallel, (2) a series configuration in which the cells are coupled to the battery bus so as to charge or discharge in series, and (3) an isolated configuration in which at least one of the plurality of cells is coupled to the battery bus and at least one of the plurality of cells is disconnected from the battery bus.

Abstract: An apparatus for producing anti-glare surfaces includes an etching cream dipping tank and a sub-tank arranged to receive a slurry of etching cream. A pumping unit is fluidly coupled to the etching cream dipping tank and the sub-tank such that the pumping unit is operable to selectively self-circulate the slurry of etching cream in the sub-tank to improve homogeneity of the etching cream and transfer a volume of the homogenized etching cream from the sub-tank to the etching cream dipping tank.

Abstract: An apparatus for producing anti-glare surfaces includes an etching cream dipping tank and a sub-tank arranged to receive a slurry of etching cream. A pumping unit is fluidly coupled to the etching cream dipping tank and the sub-tank such that the pumping unit is operable to selectively self-circulate the slurry of etching cream in the sub-tank to improve homogeneity of the etching cream and transfer a volume of the homogenized etching cream from the sub-tank to the etching cream dipping tank.