Abstract:
Coils placed at spaced locations along the path of an axially movable magnetically permeable and/or electrically conductive rod, which changes the impedance of each coil as it passes through, are connected in sets with each set comprising two series connected groups of equal numbers of parallel connected, non-adjacent coils energized by an a-c source. The voltage at the common node of each set of coils, which fluctuates as equal and unequal numbers of coils in the two groups in a given set are penetrated by the end of the rod, is compared with the voltage at the common node of a pair of series connected resistors, also energized by the a-c source, to generate one digit of an unambiguous, multi-digit, digital rod position signal. Since only one signal wire to the remote electronics is required for each set of coils, and since they only carry a voltage signal, the required wiring is minimized. Compensation is provided to maintain the location of the rod end relative to each coil at which the digital signal changes state despite variations in temperature and voltage.
Abstract:
A position indication system for detecting the position of an elongated, metallic member which is linearly movable between first and second positions along an axis corresponding to its longitudinal dimension. A sensor is operatively associated with the member for producing a first output signal which corresponds to the position of the member and which fluctuates with changes in the temperature of the member. A temperature monitoring device is operatively associated with the member for monitoring its temperature and for producing a second output signal which varies in direct response to changes in the temperature of the member. A combining circuit is connected to the sensor and to the temperature monitoring device for receiving the first and second output signals and for producing a third output signal which represents the position of the member compensated for changes in temperature of the member.
Abstract:
A rod position indicating system for a pressurized water reactor generates within containment redundant sets of digital detector signals and applies both sets to each of two communications buses each controlled by a separate bus controller/serial output device located inside of containment. A pair of redundant serial data links transmits the redundant data from each bus controller/serial output device through containment to a dedicated CRT display and the plant computer each of which generates rod position displays from redundant information selected from one of the data links. The data for each rod is selected individually from the redundant signals received on the one data link. Rod position is presented in bargraph form on a multi-page display which includes overall status information along with the detailed presentations.
Abstract:
A method for temperature compensating a position indicator which includes a sensor for producing an output signal whose magnitude corresponds to the position of an element that is linearly movable between first and second positions and which is subject to changes in temperature within a given temperature range and wherein the output signal of the sensor contains a temperature variable offset component and the rate of increase of the output signal as the element moves from the first to the second position fluctuates with changes in temperature. The method includes measuring the temperature of the medium; generating an electrical representation of an offset correction, relative to a reference temperature, required in the offset component of the output signal of the sensor at the temperature of the element; generating electrical representations of a rate correction factor, relative to a reference temperature, required for the rate of increase in the output signal of the sensor at the temperature of the element; causing the sensor to produce an output signal corresponding to the position of the element; and compensating the output signal of the sensor by forming an electrical representation of the product of the sensor output signal and the rate correction factor at the measured temperature of the medium, and adding to such product the offset correction at the measured temperature of the medium.
Abstract:
A traction elevator system including an elevator car driven by a drive arrangement having electrically isolated high and low speed components. Fixed AC and controllable DC voltages are selectively applied to the high and low speed components, respectively, at predetermined portions of the run, to control the drive torque to provide smooth operation of the elevator car.
Abstract:
A method for transmitting data in the form of a sequence of data words according to PLBus communications protocol in a channel (20) carrying data transmitted, according to a different protocol, in the form of timed bursts of a signal, comprising: producing (16) a carrier which is continuous at least for the duration of each data word; angularly modulating (14, 16) the carrier in accordance with the information contained in each data word; and transmitting the angularly modulated carrier in the channel (20).
Abstract:
An automatic tensioning control for winding stator coils characterized by a looper for winding lengths of wire into loops for stator coils, a reel of wire for paying off wire to the looper under controlled conditions, and tension sensing means between the reel and looper for measuring the tension on the wire and for providing an indicating signal for applying a restraining torque on the reel.
Abstract:
A method for demodulating the carrier signal of powerline communication networks. The method involves demodulating an HDLC data body that had been modulated through differential phase shift keyed modulation. Under the method, the data body is split with data input into a single bit digital delay circuit which outputs a delayed or "previous" binary data bit. A "present" binary data bit is input to one input of an XNOR circuit and the previous binary data bit is input into a second input of the XNOR circuit. When the present binary data bit and the previous binary data bit have unlike phases the XNOR circuit outputs a first binary data bit value. When the present binary data bit and the previous binary data bit have like phases, the XNOR circuit outputs a second binary data bit value. Preferably, the demodulated data is input into a post detection filter. The demodulation method also preferably involves the step of processing the demodulated data through a receive data correlator, a data body state machine and a variable divide counter.
Abstract:
A power line communication system which includes an electrical power line having one or more loads which feed objectionable electrical noise back into the power line. The electrical noise is attenuated across a broad frequency range to enable effective communication over the power line by a directional common mode trap located between the point where the communication signals are applied to the power line and the source of the electrical noise. The trap requires only a capacitor for each electrical phase and a 1:1 transformer having a magnetic core and single turn, straight through windings. The trap is connected to provide a low impedance path to ground for the electrical noise, while providing a high impedance to ground for the communication signals.
Abstract:
A power line carrier communication system having a carrier current transceiver (CCT) interface with an electrical power line via a buffer which automatically provides a low output drive impedance while transmitting, and a high receiving impedance when receiving, all with solid state circuitry. The length of signal transmission by the CCT is monitored and automatically prevented from continuously loading the communication network in the event of a malfunction which causes a signal transmission to exceed normal maximum transmission time. Prevention of continuous loading of the communication circuit is accomplished without adverse affect on the CCT via a crowbar circuit connected to the buffer circuitry.