A DC electric motor having a stator mounted to a substrate, the stator having a coil assembly having a magnetic core, a rotor mounted to the stator with permanent magnets distributed radially about the rotor, the permanent magnets extending beyond the magnetic core, and sensors mounted to the substrate adjacent the permanent magnets. During operation of the motor passage of the permanent magnets over the sensors produces a substantially sinusoidal signal of varying voltage substantially without noise and/or saturation, allowing an angular position of the rotor to be determined from the sinusoidal signals by utilizing a transformation matrix or piece-wise algorithm applied in substantially linear portions of the sinusoidal signals without requiring use of additional hardware encoder or position sensors and without requiring noise-reduction or filtering of the signal.

A periodic sensor signal representing a varying rotation angle detected by a rotation angle sensor is compared to a number of thresholds to detect threshold crossings of the periodic sensor signal. An output signal including a pulse pattern at the time of a threshold crossing may be generated only if the direction of rotation has not changed since an immediately preceding threshold crossing. A number of consecutive threshold crossings which take place without a change in the direction of rotation may be counted and an update of the offset register is performed only if the number of consecutive threshold crossings which take place without a change in the direction of rotation is equal to or higher less than the number of thresholds.

There is provided a light control circuit including a light detector, a frequency detector, an error amplifier, an NMOS driver and a light source. The frequency detector identifies a signal frequency according to detected voltage signals outputted by the light detector and generates a control signal accordingly. The NMOS driver changes a drive current of the light source according to an output of the error amplifier. The error amplifier changes a bandwidth thereof according to the control signal from the frequency detector to regulate a response time of the drive current of the light source.

An apparatus and a method for detecting a phase delay of a resolver are provided. The apparatus includes a resolver configured to output a signal corresponding to a rotation angle of a motor, an excitation signal generator configured to generate an excitation signal using a square wave signal, and a controller configured to differentiate the signal to obtain a differential signal, detect a time when the differential signal meets a reference voltage as a peak time of the signal, and detect a phase delay time of the signal based on the peak time of the signal and an edge time of the square wave signal.

A motor control device includes an instruction position detector that calculates, as an instruction position detection value, a position detection value at an external instruction timing. The instruction position detector includes an internal counter, a detection position calculator, and a correction value generator. The internal counter outputs a count value counted at a cyclic interval shorter than a position read cycle that is an interval at which a motor position detected by a rotary encoder mounted on a motor is read as a position detection value. The detection position calculator controls a rotation of the motor by use of the position detection value, is supplied with an external detection instruction signal including an instruction pulse, and calculates the instruction position detection value by use of a count value at the external instruction timing indicated by an edge of the instruction pulse. The correction value generator includes an external input terminal, an input circuit, a count value acquisition unit, and a correction value calculator.

A position measuring device includes a scale carrier with a measuring scale. A scanner is configured to generate position signals by scanning the measuring scale. A processor is configured to process the position signals into a digital position value. An interface is configured to communicate with downstream electronics. At least one collision sensor is assigned to the position measuring device, and is configured to generate analog or digital measured values from a time characteristic of which collision events are determinable. The measured values are fed to an evaluator configured to determine the collision events by evaluating the time characteristic of the measured values in a controller.

An encoder according to an example of the present disclosure includes a first reception unit configured to receive a position information request signal for requesting position information on an object to be detected, a position information generation unit configured to generate the position information at a position information generation timing after a predetermined delay time elapses from when the position information request signal is received, and a first transmission unit configured to transmit the position information to the outside via serial communication. The first transmission unit is configured to transmit, at least once, position information generation timing information representing the predetermined delay time to the outside via serial communication.

A position-encoding device includes a sensing device, a filtering device, a calibrating device and a compensating device. The sensing device senses the motion of a moving device to generate first and second signals. The filtering device filters the first and second signals to generate first and second filtering signal. The calibrating device captures the first and second filtering signals to obtain time and phase information of the first and second filtering signals, performs gain and offset calibration on the first and second filtering signals, and performs a phase calibration on the first and second filtering signals through first, second feedback signals and the time and phase information of the first and second filtering signals to generate first and second calibrating signals. The compensating device compensates for the first and second calibrating signals according to a lookup table, so as to generate first and second position encoding signals.

Provided is a rotation angle detection device including: an intermediate signal generation unit configured to generate an intermediate signal based on a product of a sine signal and a cosine signal which are based on a rotation angle of a rotating body; a first multiplication unit; and a first rotation angle calculation unit. The intermediate signal generation unit includes: a first multiplier configured to calculate the product of the sine signal and the cosine signal; and a first low-pass filter configured to remove frequency components equal to or higher than twice a frequency of fundamental waves of the sine signal and the cosine signal from an output of the first multiplier.

There is provided an interpolation circuit of an optical encoder including a phase shifter circuit, two multiplexers, two digital circuits and four comparators. The phase shifter circuit receives signals sequentially have a 90 degrees phase shift and outputs multiple phase shifted signals. Each of the two multiplexers receives a half of the multiple phase shifted signals and outputs two pairs of phase shifted signals, each pair having 180 degrees phase difference, respectively to two comparators connected thereto. Each of the two digital circuits controls the corresponding multiplexer to select the two pairs of phase shifted signals from the half of the multiple phase shifted signals.