Microsoft Technology Licensing, LLC

Agustya Ruchir Mehta

David Simon Lukofsky

Junius Mark Penny

Patrick Timothy Codd

David C Wyland

Scott Fullam

Jonathan Alan Dutra

Eugene Lvovich Shoykhet

Brett David Brewer

Jaron Zepel Lanier

Julian Arlo Binder

David Paul Wunsch Desrosiers

Scott Francis Fullam

David Carl Wyland

The uneven charge and discharge from non-collocated batteries within an HMD can be solved by monitoring the DC current on the paths coupled to the first battery and the second battery and making an adjustment in the path resistance to equalize, or at least reduce, the difference between the currents on the two paths. Aspects of the technology described herein monitor current on paths from two or more non-collocated batteries. When the currents are different, resistance is dynamically added to the path with the higher current to equalize the current in the two paths. The monitoring and resistance adjustment can occur during discharge from a battery to a load and during battery recharge.

Automatic DC resistance compensation

The discussion relates to spatially meshed interactive devices. One example can include a mesh component that has access to a layout of features of a facility and to information about users associated with the facility. The example can also include multiple interactive devices including sensors and communication components. The multiple interactive devices are communicatively coupled via the communication components and at least some of the multiple interactive devices are communicatively coupled to the mesh component. The multiple interactive devices are located at known positions in the facility to create a spatial mesh at the facility relative to the features.

Coupled interactive devices

A dynamic power control circuit is provided. The control circuit can detect the presence of the external power source as well as detect one or more conditions of the device. For instance, the control circuit can detect a voltage difference between a first node coupling a first power output and a system circuit and a second node coupling a second power output and the batteries. The control circuit can also detect the activation or deactivation of the external power source. Based on the inputs, the control circuit can cause the controlled resistor to dynamically adjust a level of impedance between the first node and the second node. The controlled impedance between the first node and the second node enables the system circuit to dynamically utilize power supplied by the external power source as well as power supplied by the batteries.

Dynamic power control circuit

Embodiments are disclosed for a printed circuit board. An example printed circuit board includes a ground plane comprising a pattern of an electrically conductive material. The example printed circuit board further includes a circuit trace disposed adjacent to the ground plane, where one or more characteristics of one of more of the pattern of the electrically conductive material in the ground plane and the circuit trace vary based upon a directional change of the circuit trace.

Avoiding reflections in PCB signal trace

An enhanced parallel protection circuit is provided. A system using separate battery packs in a parallel configuration is arranged with multiple protection circuit modules (PCMs). The PCMs are configured to detect fault conditions, such as over voltage, under voltage, excess current, excess heat, etc. Individual PCMs can be configured to control associated switches and/or other components. When a fault condition is detected by an individual PCM, the individual PCM triggers one or more associated switches to shut down one or more components. In addition, by the use of the techniques disclosed herein, the individual PCM can also trigger switches that are controlled by other PCMs. Configurations disclosed herein mitigate occurrences where a multi-PCM device is operating after at least one PCM has shut down. Configurations disclosed herein provide safeguards and redundant protection in scenarios where a fault event is detected by one PCM and not detected by another PCM in a parallel configuration.

Enhanced parallel protection circuit

An electronic device is configured with sub-assemblies including a main logic board, flexible printed circuit, and dual battery packs that are assembled together with electrical connectors to enable power from the battery packs to flow over a power bus that is distributed along the flexible printed circuit and main logic board. A protection circuit module (PCM) in each battery pack is configured to determine a state of each of the connections among the sub-assemblies (i.e., whether or not properly assembled to provide electrical continuity through the connector) so that power from the battery packs is switched on to the power bus only when electrical continuity is verified at each of the connectors. In the event that any connection is faulty, for example due to a misalignment of a connector during assembly that prevents electrical continuity to be established through a connector, neither PCM will switch power on to the power bus.

Enablement of device power-on with proper assembly

A power switching device (e.g., a power MOSFET) drives relatively large surges of pulsed power through a laser emitter of a Time of Flight (TOF) determining system where both the power switching device and laser emitter are closely packed on a printed circuit board having further closely packed and temperature sensitive other components. Waveforms of pulse trains that control the power switching device are programmably defined and thus may include pulse durations that are unduly large or spacing between pulses that are unduly small such that overheating may occur. A pulse duration limiting circuit is provided having an analog integrator configured to integrate over time, the programmably defined pulses and a voltage triggered clamping device coupled to an output of the analog integrator. The voltage triggered clamping device has a predetermined threshold voltage at and above which it is switched from a relatively low transconductances mode to a substantially higher transconductances mode. The voltage triggered clamping device is coupled to a current supplying circuit branch of the system, the current supplying circuit branch being one that has an ability to supply current for switching on the power switching device.

Analog limit on digitally set pulse widths

In an electronic device that employs high-speed differential signaling on one or more pairs of conductors in a flexible printed circuit, RF chokes are placed in the differential signal path and mounted directly on the flexible printed circuit which is used to interconnect a peripheral device, such as an image sensor, through a connector to another device component such as a main printed circuit board. The RF chokes are configured to suppress common-mode noise propagating in the differential pairs of conductors. In one illustrative embodiment, the RF chokes are located on the flexible printed circuit adjacent to the peripheral device to suppress common-mode noise near its source. In another illustrative embodiment, the RF chokes are mounted adjacent to the connector to suppress the common-mode noise before it has an opportunity to escape the flexible printed circuit at the major discontinuity presented by the connector.

Flexible printed circuit with radio frequency choke

In an electronic device having a compact form factor, such as a head mounted display device, flexible printed circuits may be utilized to provide interconnects between EMI-generating peripheral components and other components in the device such as those populated on main circuit boards. Coverlays utilized to protect circuit traces and ground planes in the flexible printed circuits are configured with openings that can expose ground planes at various locations throughout the electronic device. Electrical pathways are formed by conductive foam, conductive adhesives, and/or other conductive materials between the exposed ground planes and a device ground to establish multiple ground loops throughout the device that shunt EMI energy that is generated by electronic components and circuits during device operation. The coverlay openings can be positioned on the flexible printed circuits so that the lengths of the ground loops are minimized to enhance overall EMI emission management performance.

Growing community of inventors

Mountain View, CA, United States of America

Agustya Ruchir Mehta