Abstract: An electronic device may include a power driver to receive power and to selectively provide power, and a plurality of power transfer contacts to receive power from the power driver and to provide power to an external device. A controller may control the power driver to provide power to the plurality of power transfer contacts based on a plurality of time periods having a frequency shifted such that a length of a second one of the time periods is different than a length of a first one of the time periods. The controller may control the power driver to disconnect power from the power driver to the power transfer contacts during a plurality of test time durations. The controller may obtain data during the plurality of test time durations.

Abstract: An electronic device may include a power driver to receive power and to selectively provide power, and a plurality of power transfer contacts to receive power from the power driver and to provide power to an external device. A controller may control the power driver to provide power to the plurality of power transfer contacts based on a plurality of time periods having a frequency shifted such that a length of a second one of the time periods is different than a length of a first one of the time periods. The controller may control the power driver to disconnect power from the power driver to the power transfer contacts during a plurality of test time durations. The controller may obtain data during the plurality of test time durations.

Abstract: A wrist worn heart rate monitor (100) senses a noisy biosignal with one sensor (104A) in contact with the user's finger and another sensor (104B) in contact with the user's wrist. The sensed signal is modified by a filter (112), analog to digital converter (116) and digital filter (264). A correlator (272) and QRS detector (286) are used to determine characteristics of a first segment of the modified signal. A match filter (300) and learned user reference (206) are used to match a second segment of the modified signal with the determined characteristics of the first segment to produce a processed signal. The QRS detector (286), an interval judge (292), and a momentum machine (202) determine the heart rate from the processed signal. A performance predictor (260) predicts how well the heart rate monitor (100) will perform with an individual user.