Abstract: A detection module and remote load voltage sensor determine a location of a parallel arc for a power circuit between a power source and a load in real time. The detection module provides a value of voltage from the power source. A current sensor measures a value of current flowing in the power circuit to or from the power source. The remote load voltage sensor measures a value of voltage at the load. A microprocessor determines the parallel arc location from the value of voltage from the power source, the value of current, the value of voltage at the load, and a wire resistance or conductance per unit length of the power circuit. In one case, connector resistance is accounted for. In another case, the load voltage is encoded at a predetermined frequency using a switched precision resistor near the load, thereby providing a power line carrier type communication.

Abstract: A self-powered wireless transducer is disclosed for monitoring external physical conditions, such as excessive vibrations in a bearing. The transducer includes an energy conversion source, such as a piezoelectric sensor to sense the external physical condition and create a power and characteristic signal that is used to power an RF transmitting circuit. A transmitter is provided to transmit signals indicative of the external physical condition, or changes in that physical condition, such as increased vibrations in a bearing to detect bearing faults before a breakdown. In this manner, the monitored machinery can be shutdown in an orderly manner and preventative maintenance can be completed. The self-powered wireless transducer includes an voltage storage device to receive electrical voltage from the piezoelectric sensor and a voltage detector to detect the level of voltage on the voltage storage device.

Abstract: A circuit assembly senses a state of a variable state device, wherein a data signal representative of the state is communicated via wireless telegraphy. A surface acoustic wave (SAW) device, having a plurality of interdigital transducers (IDTs) comprises a wave launching IDT and a state information IDT, wherein the plurality of IDTs are in acoustical communication and the state information IDT is in electrical communication with an antenna through the variable state device. An RF transceiver communicates a trigger signal to the SAW device, wherein the trigger signal causes a launching of a SAW wave from the wave launching IDT towards the state information IDT. The state information IDT generates a signal pulse in response thereto and communicates the pulse to the antenna through the variable state device.

Abstract: A protection sensor for a lawn vehicle includes a substantially unidirectional antenna operatively coupled to a Doppler detection circuit. The Doppler detection circuit generates a radio frequency signal which is radiated by the antenna. When the radiated signal strikes an object, such as a person, animal or another moving lawn vehicle, within a predefined detection region of the sensor, the signal is reflected and received by the antenna. The Doppler detection circuit generates an output signal responsive to a difference in frequency between the radiated signal and the reflected signal, thereby indicating the presence of the moving object within the protection region of the sensor. The unidirectional antenna virtually eliminates false detections generated by the lawn vehicle, to which the sensor is mounted, or by the operator of the vehicle.

Abstract: A device (1) for photoelectrically sensing the color of an object (18) includes a plurality of light emitting diodes (4, 6, 8) emitting light in a narrow range of wavelengths and where the light is transmitted through a corresponding fiber optic bundle (10, 12, 14) with a diameter in proportion to the transmission loss of the bundle and in inverse proportion to the emitted light energy of the corresponding light emitting diode and in proportion to the spectral response of a receiving photodiode (24). A receiving section (22) utilizes a PIN type photodiode (24) with an input section (40) that matches the shape of a receiving optical fiber bundle termination (42) where the photodiode (24) converts the reflected light from the object (18) into electrical signals which are then processed by a microprocessor (28) which also controls the activation of the light emitting diodes (4, 6, 8) and outputs a signal indicative of the color of the object (18).