Abstract: A device and method are provided for determining the wear of a sole of a shoe. The device includes first and second sensors receivable in the sole of the shoe. The sensors are axially spaced and generate signals in response to corresponding impact forces acting thereon. A control circuit is connectable to the first and second sensors. The control circuit compares the difference between the first and second signals to a threshold and generates an alert signal in response to the difference between the first and second signal meeting the threshold.

Abstract: A software management system of an intelligent power conditioner with backup system option employing trend analysis for early prediction of AC power line failure. An AC line power conditioner utilizing a microprocessor based control system for providing suitable alarms when an operating input AC line is defective or the trend of measured deficiencies predicts line power failure and for initiating an inverter control signal when an inverter module is attached as an option. The software controlled system analyzes the input and output voltages, provides analysis of input voltage surges and sags, measures transient amplitude and transient pulse width, counts glitches and dropouts, measures frequency, and identifies each defect and computes associated trends, stores all accumulated data in a Log Buffer for digital printout, and then provides appropriate alarms to a user.

Abstract: Instabilities in the output voltage provided from an AC power supply system connected to a power factor correcting load are suppressed by a stabilizer which is connected across the output lines from the power supply system to the load. The stabilizing apparatus includes a rectifier having AC input nodes connected to the power supply system output lines, and DC output nodes at which DC voltage appears. A capacitor and resistor are connected in parallel across the output nodes of the rectifier. During normal operation, where the peak AC voltage from the power supply system is substantially constant, the capacitor charges up to a voltage level near the zero to peak value of the AC voltage waveform, with the charge on the capacitor slowly dissipated through the parallel resistor at a rate that does not substantially dissipate the charge between peaks of the AC voltage waveform.

Abstract: The DC to AC power inverter is of the class B, C, D or E type and includes a battery, at least one power SCR and associated capacitor circuitry, at least one input winding on a main transformer core and at least one output secondary winding on the transformer core. Such inverter requires a quiescent current to establish operating current for capacitor commutation charge and includes a feedback loading circuit for feeding current generated by the quiescent current back to the battery. The inverter also includes a self-detecting load demand circuit coupled to a line from said output winding for cyclically energizing the inverter, for sensing a minimum AC load and for holding said inverter in an energized state until less than a minimum AC load is sensed during an energizing cycle.