Abstract: A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller.

Abstract: A combination current sensor and relay has an improved housing. In one aspect, the housing includes light emitting diodes on an upper surface that indicate open circuit and short circuit conditions. In another aspect, the housing includes a securement structure for a circuit board that includes the transformer and switches for device operation, together with aligned openings therein for routing wires to external devices. In another aspect, a multiple position switch is included on the upper surface that indicates multiple modes of operation of the device. In another aspect, the housing may be assembled in multiple parts by affixing a first portion to a support, a circuit board to the first portion, and a second portion to the first portion. In another aspect, the housing is suitable for engagement to alternatively a junction box and a duplex box. In another aspect, the configuration of the upper surface provides usability advantages.

Abstract: A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller.

Abstract: A highly accurate relative humidity sensing device includes a sensory unit having a humidity sensitive capacitor which has a capacitance which changes as a function of relative humidity. The sensor unit is housed in a tubular unit which is inserted through an aperture into the environment to be measured which is typically a duct or the like. The unit is constructed for easy removability. A housing having a central aperture is bolted to the duct and the tube containing the sensor is inserted through the aperture into a hole drilled into the sidewall of the duct. The cylinder holding the sensor is grasped by a releasably detachable securing structure. By releasing the securing structure, the cylinder may be withdrawn from the duct for replacement of the sensor.

Abstract: A humidity sensing device comprises a sensor unit including a humidity sensitive capacitor having a capacitance which changes as a function of relative humidity, an oscillator circuit including the humidity sensitive capacitor wherein the output frequency of the oscillator circuit is a function of capacitance, and a sensor memory unit having stored calibration data for said humidity sensitive capacitor. A data processing unit is coupled to the sensor unit and includes a data processing circuit coupled to an output of said oscillator circuit, wherein said data processing circuit provides an output indicative of relative humidity as modified by the calibration data received by and stored in another memory unit as associated with such data processing circuit.

Abstract: A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller.

Abstract: A sensor linked with a power cable to produce a first signal in response to the presence of at least one of a sensed current and a sensed voltage within the power cable. The measuring circuit is electrically connected to the sensor to produce a second signal in response to the first signal representative of the magnitude of at least one of the sensed current and the sensed voltage within the power cable. The measuring circuit also produces a third signal in response to the first signal representative of a sensed frequency of at least one of the sensed current and the sensed voltage within the power cable. The measuring circuit includes a model of a set of predetermined relationships between a plurality of reference frequencies and a reference amplitude for each of the reference frequencies for at least one of the sensed voltage and the sensed current of the power cable.

Abstract: A power measuring system includes a transformer that produces a voltage signal in response to the presence of a changing current within a power cable. An input circuit is electrically connected to the transformer for receiving the voltage signal, and produces an analog current signal representative of the changing current within the power cable, in response to receiving the voltage signal. A transmission line has a first end electrically interconnected with the input circuit so as to receive the analog current signal and has a second end electrically interconnected with an output circuit located at a location remote from the first end. The output circuit receives the analog current signal and produces a resultant signal in response to receiving the analog current signal. The resultant signal may be used to provide a meter display. A housing for a sensing transformer having a split toroidal core is disclosed.