Abstract: In a method and device for the cyclic digital transmission of a position value of a moving object with inertial mass, the value range of the transmitted position value is restricted such that no complete rotation or, in the case of a linear motion, other complete period caused by mechanical conditions may be mapped, and the actual position is formed by detecting value-range exceedances in an evaluation unit.

Abstract: Systems, devices, and techniques are disclosed for administering and tracking medicine to patients and providing health management capabilities for patients and caregivers. In some aspects, a system includes an injection pen device including a dose setting mechanism, a dispensing mechanism, and an electronics unit to generate dose data associated with a dispensing event of a dose of the medicine dispensed from the injection pen device and time data associated with the dispensing event; a mobile device in wireless communication to receive and process the dose data; and a software application configured to determine a recommended dose based on health data and contextual data associated with a user of the injection pen device, the software application including a learning dose calculator module to adaptively calculate the recommended dose of the medicine based on time-relevant and circumstances-relevant data specific to the user of the injection pen device.

Abstract: Implementations of a resolver sensor system may include a signal amplifier portion configured to be coupled to a magnetoresistive sensor coupled with a movable element where the signal amplifier portion configured to receive a sine signal and a cosine signal from the magnetoresistive sensor; and a sensor offset canceling portion coupled with a signal amplifier portion. The sensor offset canceling portion may be configured to generate a direct current offset correction signal to the signal amplifier portion which uses two or more amplifiers included in the signal amplifier portion to receive the sine signal and the cosine signal and to generate corresponding adjusted digital sine and cosine signals. The signal amplifier portion may be configured to provide the adjusted digital sine signal and the adjusted digital cosine signal to one of the servo signal processor or the system controller for use in determining a position of the movable element.

Abstract: A control system in which an encoder and a controller are connected by serial communication. The encoder includes a data transmission unit configured to: embed, in serial data, position information which is information related to a position of a detection object, and position information generation timing information that indicates a timing at which the position information is generated; and transmit to the controller the serial data. The controller includes a correction unit configured to correct, based on the position information and the position information generation timing information received from the encoder, the position information of the detection object.

Abstract: A method and device for the cyclic digital transfer of a position value of a moving object having inertial mass, the value range of the transferred position value being limited in such a way that no whole revolution or, in the case of a linear motion, other complete period that is conditional upon mechanical conditions is mappable, and the actual position is generated by detecting, in an evaluation unit, instances of the value range being exceeded.

Abstract: A motor control device may include a position command output means, a first subtraction means that calculates and outputs a position deviation, a position control means, a second subtraction means that calculates and outputs a position deviation, a speed control means that outputs a torque command, a limiter limits the level of the torque command, a motor drive means, and a voltage fluctuation detection means. When the voltage fluctuation detection means detects that the voltage of said power source has dropped below a predetermined reference level, either the position command output means varies the position command so as to reduce the rotational speed of the motor and/or said position control means limits said speed command to be output.

Abstract: In a semiconductor device, a sine wave signal is input to a first input part and a cosine wave signal is input to a second input part. A multiplexer alternately selects one of the sine wave signal and the cosine wave signal. An analog to digital converter converts the output signal of the multiplexer into a digital value. A switching circuit is coupled between at least one of the first and second input parts and the multiplexer. The switching circuit is configured to be able to invert the input sine wave signal or the input cosine wave signal, in order to reduce the angle detection error due to the non-linearity error of the A/D converter.

Abstract: A sensor interface operates to communicate a sensed quantity along one or more processing pathways and in different data representations. The signal representations can be swapped along one or more locations of the signal processing branches. These branches are independent from one another and combined at an interface component for transmission along a single path or node for a control unit.

Abstract: An innovative path guidance system and method has been invented that in a preferred embodiment allows visually impaired people to follow a dynamically changing path that avoids obstacles and arrive at a destination with minimal intervention by a sighted guide. The disclosed invention has the leader set a track electronically, and employs but is not limited to haptic feedback and audible alerts used in combination or individually, to help the visually impaired person control his or her trajectory. The visually impaired follower can be following a leader setting the path in real time or following a path established by a guide at an earlier time and recorded.

Abstract: Techniques for a system, article, and method of low-complexity histogram of gradients generation for image processing may include histogram of gradients generation for image processing including the following operations: obtaining image data including horizontal and vertical gradient components of individual pixels of an image; associating the horizontal and vertical gradient components of the same pixel with one of a plurality of angular channels depending on the values of the horizontal and vertical gradient components; determining a gradient magnitude and a gradient orientation of individual angular channels after the horizontal and vertical gradient components are assigned to the channels; and generating a histogram of gradients by using the gradient direction and gradient magnitude of the angular channels.

Abstract: An innovative path guidance system and method has been invented that in a preferred embodiment allows visually impaired people to follow a dynamically changing path that avoids obstacles and arrive at destination with minimal intervention by a sighted guide. The disclosed invention has the leader set a track electronically, and employs but is not limited to haptic feedback and audible alerts used in combination or individually, to help the visually impaired person control his or her trajectory. The visually impaired follower can be following a leader setting the path in real time or following a path established by a guide at an earlier time and recorded.

Abstract: A circuit is provided for detecting peaks of a sinusoidal input signal includes circuitry for generating first and second sinusoidal output signals that are out of phase with one another and with the sinusoidal input signal. A comparator block compares the sinusoidal output signals to determine instances where the amplitudes of the first and second sinusoidal output signals cross over each other. The sinusoidal output signals may lead the sinusoidal input signal somewhat so that, after taking into account processing delay, the indicated crossover instances substantially coincide with peaks in the sinusoidal input signal such that a trigger signal generated by the circuit accurately indicates the timing of the peaks.

Abstract: A signal convertor includes a first sensor configured to generate a first signal and a second signal and first and second multiplexers configured receive the first and second signals, respectively, and generate samples. The signal convertor also includes an analog-to-digital (A/D) convertor configured to convert the samples and a processor configured to multiply the samples by a sine vector and by a cosine vector and determine a magnitude of the first and second signals based upon the product of the samples and the sine vector and the product of the samples and the cosine vector. A method for converting a signal is also disclosed.

Abstract: A position-measuring device includes a code carrier having a first graduation track and a second graduation track, the second graduation track being an incremental graduation track. A first detector system is configured to scan the graduation tracks so as to generate first position signals. A second detector system is configured to scan the second graduation track so as to generate second position signals. A first position-processing unit is configured to process the first position signals so as to yield a first absolute position value. A second position-processing unit is configured to process the second position signals so as to yield a second absolute position value. The first position-processing unit is configured to feed an absolute auxiliary position value to the second position-processing unit. The second position-processing unit is initializable with the absolute auxiliary position value.

Abstract: Systems and methods for flow sensing in a conduit are provided. One system includes a flow disturber disposed in a flow conduit and configured to impart a flow disturbance to the fluid flow. The system further includes a plurality of flow sensors disposed in the flow conduit and responsive to flow characteristics in the flow conduit. The system also includes a frequency resolver configured to determine frequency information related to the fluid flow based on the flow characteristics. The frequency resolver uses one or more time sample windows to select data samples for use in determining the frequency information, wherein a length of one or more of the time sample windows is based at least in part on the flow characteristics. The system additionally includes a processor configured to determine a flow rate of the fluid flow in the flow conduit using the frequency information.

Abstract: A digital filter for removing a PWM noise from a sampling data includes: an averaging filter. The sampling data is obtained by sampling a control amount of a control object, which is driven at a driving frequency in a PWM control manner, at a sampling frequency. The PWM noise includes fundamental and harmonic wave components. The averaging filter calculates an average of the sampling data, which is sampled most recent predetermined sampling times providing an averaging number. The sampling frequency and the averaging number are determined to satisfy a relationship that an absolute value of a difference between the sampling frequency multiplied by a predetermined first integer and the harmonic wave frequency is equal to the sampling frequency divided by the averaging number and multiplied by a predetermined second integer in a frequency range between zero and a Nyquist frequency when the fundamental and harmonic wave components are removed.

Abstract: According to one aspect, a resolver-to-digital converter includes a first filter configured to receive a first delta-sigma modulated resolver input. A second filter is configured to receive a second delta-sigma modulated resolver input. A summing junction is configured to output a difference between a scaled output of the first filter and a scaled output of the second filter. A controller is configured to generate a controller output based on a product of a demodulator and an output of the summing junction. An integrator is configured to generate an estimated position based on the controller output. The resolver-to-digital converter also includes a compensator configured to generate a compensated estimated position based on the controller output and a compensation offset delay adjustment.

Abstract: According to one aspect, a resolver-to-digital converter includes a first filter configured to receive a first delta-sigma modulated resolver input. A second filter is configured to receive a second delta-sigma modulated resolver input. A summing junction is configured to output a difference between a scaled output of the first filter and a scaled output of the second filter. A controller is configured to generate a controller output based on a product of a demodulator and an output of the summing junction. An integrator is configured to generate an estimated position based on the controller output. The resolver-to-digital converter also includes a compensator configured to generate a compensated estimated position based on the controller output and a compensation offset delay adjustment.

Abstract: A window-enabled TDC and method of detecting phase of a reference signal. One embodiment of the window-enabled TDC includes: (1) a window generator configured to receive a reference signal and a clock signal, and (2) a TDC circuit coupled to the window generator and configured to be enabled based on the reference signal and disabled based on the clock signal.

Abstract: The present invention is typically embodied as a portable handheld unit that generates synchro signals for input into synchro motors and other synchro devices. A primary genre of inventive application is the testing of hardware and software in synchro systems. The inventive unit typically includes a numeric keypad, an LCD display, a microcontroller, a serial-to-parallel binary data converter, and at least one digital-to-synchro converter. The keypad and display are used to enter decimal data. The microcontroller converts the decimal data to serial binary data. The serial-to-parallel binary data converter converts the serial binary data to parallel binary data. The digital-to-synchro converter(s) convert(s) the parallel binary data to synchro analog data. Some inventive embodiments implement plural digital-to-synchro converters individually corresponding to channels for independently outputting synchro signals. Each channel can represent a specific type of synchro operation, e.g.

Abstract: An encoder includes a detector, a first position data calculator, a first data converter, an approximation device and a third position data calculator. The first data converter is configured to convert a first position data calculated by the first position data calculator into second position data whose second width in bits is longer than a first width in bits of the first position data. The approximation device is configured to calculate an approximation function that derives position data when timing data is input, based on a plurality of the second position data converted by the first data converter at a plurality of successive sampling timings, respectively. The third position data calculator is configured to calculate third position data indicating a position of a detection target at an output timing, based on the approximation function calculated by the approximation device.

Abstract: A motor speed determining circuit determining a rotation speed of a motor is provided and a processing of generating motor driving waveform is switched in accordance with the rotation speed of the motor. A resolver signal outputted from a resolver 2 is converted to a digital value by an R/D converter 3, and inputted to a computing circuit of resolver value correction 5 via an R/D conversion interface 4. A current value of a motor M is converted to a digital value by an A/D convertor 8. The computing circuit of resolver value correction 5 computes a resolver correction value of the inputted digital signal and calculates positional data from a corrected resolver value. The computing circuit of motor control computes a current instruction value from a motor current value subjected to digital conversion by the A/D converter 8 and a motor current instruction value etc.

Abstract: A digital-to-synchro converter (“DSC”) is a device that converts digital signals to analog signals suitable for use by a synchro device. A conventional DSC implements complex circuitry to take digital input and generate [V Sin({acute over (?)}t) Sin(?)] and [V Sin({acute over (?)}t) Cos(?)] analog signals, and a Scott-T transformer to transform these analog signals into [V Sin({acute over (?)}t) Sin(?)], [V Sin({acute over (?)}t) Sin(?+120)], and [V Sin({acute over (?)}t) Sin(?+240)] analog signals. An inventive DSC, as typically embodied, implements a microcontroller to take digital input and generate [V Sin({acute over (?)}t) Sin(?)] and [V Sin({acute over (?)}t) Sin(?+120)] digital signals, a digital-to-analog converter to convert these digital signals to [V Sin({acute over (?)}t) Sin(?)] and [V Sin({acute over (?)}t) Sin(?+120)] analog signals, and a regular transformer (i.e.

Abstract: This resolver digital converter 10 includes a band pass processing unit that is disposed between a conversion unit and a multiplication unit and passes only a signal of a predetermined band through processing performed with a period that is shorter than the sampling period of an analog-to-digital converter and corrects the gains of digital signals before being input to the multiplication unit by using gain correction values that are set based on the maximum value and the minimum value of each one of digital signals passing through the band pass processing unit.

Abstract: A method is presented for converting the sine/cosine signals from an optical encoder into a high-resolution position signal for use by a position control system while eliminating common noise and error sources. The improved noise performance resulting from the alias-free demodulation of encoder signals improves precision and reduces power consumption in precision motion control applications. The adaptive compensation of harmonic distortion eliminates errors related to offset, gain and quadrature of the encoder channels. The interpolator is able to process encoder signals at extremely high resolution without the speed limitation of prior art encoder interpolators.

Abstract: A CORDIC processor has a plurality of stages, each of the stages having a X input, Y input, a sign input, a sign output, an X output, a Y output, a mode control input having a ROTATE or VECTOR value, and a stage number k input, each CORDIC stage having a first shift generating an output by shifting the Y input k times, a second shift generating an output by shifting X input k times, a multiplexer having an output coupled to the sign input when the mode control input is ROTATE and to the sign of the Y input when the mode input is VECTOR, a first multiplier forming the product of the first shift output and the multiplexer output, a second multiplier forming the product of the second shift output and an inverted the multiplexer output, a first adder forming the X output from the sum of the first multiplier output and the X input, and a second adder forming the Y output from the sum of the second multiplier output and the Y input.

Abstract: An interface system between an RDC and a connected resolver dynamically matches an input range of the RDC to the output range of the resolver's output signals. The interface system may include methods and/or apparatuses to determine the amplitude of sinusoidal input signals presented to the RDC by the resolver and to compare the amplitude against high and low threshold values. A gain control signal may be generated, which may be corrected if the detected amplitude either exceeds the high threshold or falls below the low threshold. The gain control signal may be output to a circuit in the RDC or in the resolver that corrects any mismatch that occurs between the RDC input and the resolver output. For example, the gain control signal may control the amplitude of an excitation signal applied to a primary of the resolver or the gain control signal may be applied to an analog to digital converter at the input of the RDC to control its effective input range.

Abstract: System and method for digitizing analog voltage signals. A first voltage signal may be received at a comparator. A ramp signal may be received at the comparator. The ramp signal may be generated by a ramp generator. An output signal may be generated by the comparator. The output signal may indicate whether the analog voltage signal or the ramp signal is greater. The output signal may be conveyed to logic circuitry by the comparator. Control information may be conveyed by the logic circuitry to the ramp generator. The ramp generator may generate the ramp signal based on the control information. The logic circuitry may determine a digital representation of the first voltage signal based on the output signal from the comparator and the control information.

Abstract: A system and method for reducing noise in resolver-to-digital converters (RDC) using a cascaded tracking loop filter. In some embodiments, one or more tracking loop filters may be implemented in a cascade to attenuate carrier harmonic frequencies in the digitized output of an RDC. Where a plurality of tracking loop filters are implemented, the output of one tracking loop filter may be input into a successive tracking loop filter.

Abstract: The inventive data conversion device is typically embodied as a modular unit including a PCBA and a frame that houses it. The PCBA includes a PCB and electronic components mounted thereon including a computer and one or more conventional conversion devices, viz., at least one conventional synchro-to-digital converter and/or at least one conventional digital-to-synchro converter. According to typical inventive synchro-to-digital conversion, analog synchro data (received from a synchro) is converted by the synchro-to-digital converter(s) to lower-level-format parallel-binary-angle digital synchro data, which in turn is converted by the computer to higher-level-format digital synchro data.

Abstract: According to one embodiment, a digital converter is provided to process output signals of a resolver attached to a rotating apparatus. These output signals are converted into digital signals by ?? AD converters. Multiplication units receive the digital signals outputted from the ?? AD converters. A subtraction unit subtracts the outputs of the multiplication units. A synchronous detection unit detects the output of the subtraction unit based on a synchronization signal synchronously. An angular velocity calculation unit adjusts a proportional gain of an output of the synchronous detection unit, compensates the phase thereof, and calculates the angular velocity of the rotating apparatus. A rotational angle calculation unit calculates a rotational angle by integrating the angular velocity. Cosine and sine output units output a cosine and a sine corresponding to the obtained rotational angle to the multiplication units, respectively.

Abstract: A control device for a travel motor mounted to a vehicle has a resolver which works as a rotation-angle sensor. The control device has a RDC which calculates a rotation-angle output value ? based on rotation detection signals Sa, Sb transferred from the resolver. The control device supplies electric power to the travel motor based on the rotation angle output value ?. The RDC calculates “sin(???)” as an error deviation ? based on the signals Sa and Sb and the rotation-angle output value ?. The RDC calculates an angular acceleration by multiplying the error deviation ? with a gain (=Ka·Kb), and integrates the angular acceleration two times in order to obtain a next rotation-angle output value. A gain control part of the RDC decreases the gain when the judgment means judges that the travel motor rotates at a constant rotation speed.

Abstract: A system and method for reducing noise in resolver-to-digital converters (RDC) using a cascaded tracking loop filter. In some embodiments, one or more tracking loop filters may be implemented in a cascade to attenuate carrier harmonic frequencies in the digitized output of an RDC. Where a plurality of tracking loop filters are implemented, the output of one tracking loop filter may be input into a successive tracking loop filter.

Abstract: Methods and apparatus are provided for deriving precision position and rate information for motors using relatively low precision analog sensors, and for implementing compensation techniques that overcome inherent sensor errors and rotor magnet flux tolerances.

Abstract: The present invention relates to a method for ensuring a constant target speed of a battery driven electrical motor, the battery driven electrical motor being adapted to move a piston rod in an injection device so as to inject a set dose of medicine from the injection device, the method comprising the steps of setting a first target speed to be reached by the motor, determining whether the first target speed can be reached, and, if the first target speed can be reached, maintaining the first target speed until a set dose of medicine has been injected from the injection device, or if the first target speed cannot been reached, setting a second target speed.

Abstract: A rotation-position detection system according to the present invention is configured with a resolver mounted in a brushless motor and a motor controller. The motor controller outputs an excitation signal to the resolver and an A/D converter thereof alternately applies analogue/digital conversion to a sine wave signal and a cosine wave signal outputted from the resolver so that a rotation position of the motor is calculated.

Abstract: A reference signal generation circuit generates a reference signal used in synchronous detection for removing an excitation signal component in an angle calculation section that converts a detection angle ? obtained from two-phase resolver detection signals output from a resolver, to a digital output angle ?. The reference signal generation circuit includes a first multiplier, a second multiplier, and an adder. The first multiplier multiplies one of the resolver detection signals sin ? sin(?t+??) by the sine value sin ? of the digital output angle ? obtained from the angle calculation section. The second multiplier multiplies the other resolver detection signal cos ? sin(?t+??) by the cosine value cos ? of the digital output angle ? obtained from the angle calculation section. The adder adds the output of the first multiplier and the output of the second multiplier to output the sum signal sin(?t+??) as the reference signal.

Abstract: An angle detection device of the present invention includes: a stator which includes a plurality of salient pole portions which are formed on a flat sheet made of a magnetic material and are raised by bending, each salient pole portion constituting a winding magnetic core on which a winding member for excitation and a winding member for detection are mounted; and a rotor which is made of a magnetic material and is provided rotatably relative to the stator such that gap permeance between the rotor and each salient pole portion is changed due to the rotation of the rotor about a rotational axis of the rotor. According to the angle detection device of the present invention, it is possible to provide the angle detection device which can largely reduce the number of parts and can realize the reduction of cost and the enhancement of reliability.

Abstract: A rotation angle detecting device for a motor includes a first capacitor connected in parallel with a first winding of a rotor of the motor, and a second capacitor connected in parallel with a second winding of the rotor. The second capacitor has a capacitance different from that of the first capacitor. A rotation angle calculator of the rotation angle detecting device counts a number of amplitude changes of current detected by a current detector. The rotation angle calculator increases or decreases a value of the counting in accordance with a rotation direction detected by a rotation direction detector.

Abstract: According to one embodiment, a digital converter is provided to process output signals of a resolver attached to a rotating apparatus. These output signals are converted into digital signals by ?? AD converters. Multiplication units receive the digital signals outputted from the ?? AD converters. A subtraction unit subtracts the outputs of the multiplication units. A synchronous detection unit detects the output of the subtraction unit based on a synchronization signal synchronously. An angular velocity calculation unit adjusts a proportional gain of an output of the synchronous detection unit, compensates the phase thereof, and calculates the angular velocity of the rotating apparatus. A rotational angle calculation unit calculates a rotational angle by integrating the angular velocity. Cosine and sine output units output a cosine and a sine corresponding to the obtained rotational angle to the multiplication units, respectively.

Abstract: A resolver apparatus and method are provided. The apparatus comprises a source generation unit for generating a uni-phase source signal to excite a resolver, wherein said source generation unit comprises a low distortion oscillator, a variable phase shifter, and a capacitive resolver driving network; and a signal output unit for generating a two-phase output signal, wherein said signal output unit comprises the resolver, a signal detector and level adjuster, an angular position measurement unit, and an angular position compensation unit. The method comprises generating a source signal to excite a resolver; transmitting the source signal through a variable phase shifter; transmitting the source signal through at least one capacitive passive element serially connected to each coil winding of the resolver; outputting a displacement signal generated by the resolver to a resolver-to-digital converter; and converting said displacement signal into a digital position using the resolver-to-digital converter.

Abstract: A multiturn rotary encoder includes: a single-turn unit, including a code carrier and a single-turn evaluation unit for processing single-turn position signals to form a single-turn code word; a first multiturn unit, including at least one first multiturn code carrier and a first multiturn evaluation unit for processing first multiturn position signals to form a first multiturn code word that indicates the number of revolutions covered by input shaft; and a second multiturn unit, including at least one second multiturn code carrier and a second multiturn evaluation unit for processing second multiturn position signals to form a second multiturn code word that likewise indicates the number of revolutions covered by the input shaft. The functioning of the multiturn units is ascertainable by the multiturn code words generated independently of each other.

Abstract: Disclosed are an apparatus and method for sensing a rotor position, and an electric power steering system using the same.

Abstract: A pulse generating device includes a rotatable disc having a plurality of patterns that are formed on a surface of the rotatable disc in a circumferential direction of the rotatable disc, and three pulse generators to each detect the plurality of patterns formed on the rotatable disc and to respectively generate three pulse signals each corresponding to a rotational speed of the rotatable disc based on the detected patterns. The three pulse generators are evenly spaced at intervals of 120 degrees of angle with respect to a rotational axis of the rotatable disc in the circumferential direction of the rotatable disc.

Abstract: The inventive data conversion device is typically embodied as a modular unit including a PCBA and a frame that houses it. The PCBA includes a PCB and electronic components mounted thereon including a computer and one or more conventional conversion devices, viz., at least one conventional synchro-to-digital converter and/or at least one conventional digital-to-synchro converter. According to typical inventive synchro-to-digital conversion, analog synchro data (received from a synchro) is converted by the synchro-to-digital converter(s) to lower-level-format parallel-binary-angle digital synchro data, which in turn is converted by the computer to higher-level-format digital synchro data.

Abstract: A rotary electrostatic encoder comprising a disk-shaped fixed plate having a first transmission electrode, a second transmission electrode, and four reception electrodes; a disk-shaped rotating plate having a first induction electrode superposed on and facing the first transmission electrode, and a second induction electrode positioned on the inside of the first induction electrode and superposed on and facing the second transmission electrode, a portion of the second induction electrode being a protruding eccentric circular part; transmission means for applying a transmission signal between the first transmission electrode and the second transmission electrode; and signal processing means for generating an output signal relating to the absolute rotational displacement of the rotating plate on the basis of two signal components generated from the four reception electrodes.

Abstract: A signal conditioning circuit time share multiplexes anti-aliasing filters and an A/D converter. A plurality of first tier multiplexers each time share multiplex one of a plurality of antialiasing filters between a plurality of AC or baseband input signals from a plurality of sensors. A second tier multiplexer selects its inputs from the outputs of the first tier multiplexers. The output of the second tier multiplexer feeds a high speed A/D converter. Thus, the A/D converter is time share multiplexed by the second tier multiplexer. In this manner, a plurality of sensors can share a single A/D converter. After allowing a settling time for the multiplexers and antialiasing filters, a plurality of samples of the input signals are taken, such as for one period. The samples of each AC input signal are multiplied by a sine vector and a cosine vector. The product vectors are then each averaged and the root mean square of the two averages yields the magnitude of the input signal.

Abstract: A signal conditioning circuit time share multiplexes anti-aliasing filters and an A/D converter. A plurality of first tier multiplexers each time share multiplex one of a plurality of antialiasing filters between a plurality of AC or baseband input signals from a plurality of sensors. A second tier multiplexer selects its inputs from the outputs of the first tier multiplexers. The output of the second tier multiplexer feeds a high speed A/D converter. Thus, the A/D converter is time share multiplexed by the second tier multiplexer. In this manner, a plurality of sensors can share a single A/D converter. After allowing a settling time for the multiplexers and antialiasing filters, a plurality of samples of the input signals are taken, such as for one period. The samples of each AC input signal are multiplied by a sine vector and a cosine vector. The product vectors are then each averaged and the root mean square of the two averages yields the magnitude of the input signal.

Abstract: A band elimination filter 35 that eliminates or reduces a low frequency noise superposed on resolver signals S1 and S2 is provided between a synchronous detection circuit 34 that performs synchronous detection by referring to an excitation signal and a controller 36 that controls a digital angle output ? to make a deviation (sin(???)), which is the output of the synchronous detection circuit, zero.

Abstract: A resolver includes an excitation signal generator which generates a sine wave and a cosine wave as an excitation signal, a rotor which receives the excitation signal, and a rotary transformer which detects an output signal of the rotor, the resolver being arranged to detect angle information of the rotor. The resolver further includes a controller which outputs angle information at a zero cross point of the output signal detected by the rotary transformer. The resolver can provide high detection accuracy and be low in cost.