Abstract: A self testing fault detector having a line side and a load side and a conductive path there between, said apparatus is provided. The self testing fault detector includes a controller, adapted to perform periodic status tests on a protection circuit of the self testing fault detector without interrupting power to the load.

Abstract: A fault interrupter apparatus having a line side and a load side and a conductive path there between. The apparatus includes a solenoid that is adapted to move a plurality of contacts disposed in the conductive path from a first position to a second position, an alarm indicator that is adapted to provide status information on the operation of the fault interrupter apparatus, and a processor that is adapted to detect four condition states of the fault interrupter and indicate the four condition states of the fault interrupter using the alarm indicator.

Abstract: A system and method are provided for ensuring increased accuracy of individual relays (e.g., within a control system including a sensor) to close substantially coincidentally with respect to a current zero-crossing of an incoming power supply waveform. To determine timing of contact operation, a microcontroller operates the contacts in response to one of a series of test pulses, and determines the amount of time required for contact operation. The difference between timing of contact operation and zero-crossing is determined and adjusted to offset errors incurred by microcontroller threshold variations and power supply voltage variations. The calibrated value is then provided to the sensor in order to extend sensor life.

Abstract: A system and method are provided for ensuring increased accuracy of individual relays (e.g., within a control system comprising a sensor) to close substantially coincidentally with respect to a current zero-crossing of an incoming power supply waveform. To determine timing of contact operation, a microcontroller operates the contacts in response to one of a series of test pulses, and determines the amount of time required for contact operation. The difference between timing of contact operation and zero-crossing is determined and adjusted to offset errors incurred by microcontroller threshold variations and power supply voltage variations. The calibrated value is then provided to the sensor in order to extend sensor life.

Abstract: A bar code reader has a light emitting source for illuminating a bar code, a photosensing element for sensing the light reflected from the bar code and an amplifier having an input to which the photosensing element is coupled. A single series path is employed to generate a current which is used to operate the light emitting element and to produce a bias voltage to bias the amplifier at a predetermined level. Using the same current to drive the light emitting element and to develop the bias voltage reduces the power consumed to operate the bar code reader.