An absolute electromagnetic position encoder comprises a readhead and an absolute scale. The readhead comprises a spatially modulated signal coupling configuration and a readhead processor. The absolute scale comprises a passive signal pattern, an active signal pattern and a timing and activation circuit connected to the active signal pattern. During a first signal generating cycle, the readhead processor is configured to provide first cycle spatially periodic signals and the timing and activation circuit is configured to receive and store energy. During a second signal generating cycle, the timing and activation circuit is configured to drive the active signal pattern and the readhead processor is configured to provide at least one corresponding second cycle signal. The readhead processor is configured to determine an absolute position of the readhead relative to the absolute scale based on at least the second cycle signal and the first cycle spatially periodic signals.

An absolute electromagnetic position encoder comprises a readhead and an absolute scale. The readhead comprises field generation and detection configuration and a readhead processor. The absolute scale comprises an active periodic signal pattern, an active absolute signal pattern, and timing and activation circuitry connected to the active signal pattern. During an energy transfer cycle, the timing and activation circuitry is configured to receive and store energy from the readhead. During a first signal generating cycle, the timing and activation circuitry is configured to drive the periodic spatially modulated signal generating element in order to generate first cycle spatially periodic signals in the first cycle field detector. During a second signal generating cycle, the timing and activation circuitry is configured to drive the first spatially modulated signal generating element in order to provide at least one corresponding second cycle signal in the readhead. The readhead processor is configured to determine an absolute position of the readhead relative to the absolute scale based on at least the second cycle signal and the first cycle spatially periodic signals.

A magnetic sensor may include a first sensing element and a second sensing element. The first sensing element may be capable of sensing a first component of a magnetic field that is non-parallel to an axis formed by an intersection of a first plane and a second plane. The first plane may be a plane in which a tooth wheel rotates, and the second plane may include a first surface of the first sensing element and a second surface of the second sensing element. The first component of the magnetic field may be on the second plane. The second sensing element may be capable of sensing a second component of the magnetic field. The second component of the magnetic field may be on the second plane.

A method of determining an angle by an encoder includes generating a first angle data based on a rotation of a bipolar magnet and a second angle data based on a rotation of the multipolar magnet; determining a first waveform signal based on the first angle data and a second waveform signal based on the second angle data; converting the first waveform signal into a third waveform signal having a cycle similar to the second waveform signal; calculating an angle result value as a function of the second angle data and a determined value about a location of a rotation cycle of the multipolar magnet based on a difference between the second waveform signal and the third waveform signal; and determining an absolute angle corresponding to the calculated angle result value based on stored angle data.

A magnetized scale (1a) in which magnetic pole pairs each formed of a first magnetic portion (11a) and a second magnetic portion (12a) having different magnetic properties are arranged with a period of a magnetic pole pair width 2λ, and a magnetosensitive device (2) in which n magnetosensitive elements (21a to 21e) are arranged with a magnetosensitive element pitch P so that λ=nP may be established are arranged so as to be opposed to each other with a predetermined air gap therebetween. Output values output from the n magnetosensitive elements (21a to 21e) in parallel are analyzed to calculate a relative position between the magnetosensitive device (2) and the magnetized scale (1a) as a position detection resolution of λ/n.

A linear conveyer includes a stationary module and a slider. The stationary module includes a frame extending linearly, a stator including armature coils and fixed to the frame, a rail, and a magnetic sensor. The slider movable along the rail with a driving linear motor includes magnetic poles, a rail guide fitted on the rail, and a magnetic scale. The magnetic scale includes a plastic magnet having magnetic poles and extending along an extending direction in which the rail extends, and a back yoke where the plastic magnet is placed. A position of the slider is detected by the magnetic sensor and the magnetic scale. The plastic magnet has a fixed portion that is fixed with respect to the back yoke and a portion other than the fixed portion, the portion being movable relative to the back yoke along an extending direction in which the magnetic scale extends.

A first counter is incremented when a first rotational speed sensing device detects a falling edge of one of the teeth of a single multi-tooth target wheel, a second counter is incremented when a second rotational speed sensing device detects a falling edge of one of the teeth, and a third counter is incremented when either of the first and second rotational speed sensing devices detects either of a rising edge and a falling edge of one of the teeth. A direction of rotation is determined based upon the third counter and a rotational speed of the rotatable member is determined based upon one of the first and second counters. The rotatable member is indicated to be at zero speed when the rotational speed is less than a threshold speed and the direction of rotation changes between a positive direction and a negative direction.

The invention discloses a position measuring mechanism and a measuring method of a linear motion system in which two sensors are respectively disposed on two sides of a stator, in addition to allowing a moving portion to perform bidirectional movement, under a premise of not increasing a quantity of the sensors, a measuring range of the sensors can be calculated based on information measured by the sensors themselves. Furthermore, the invention further combines measurement sections respectively measured by the two sensors to ensure an accuracy of position feedback, instead of the conventional technique using an operational method of combining sinusoidal and cosine signals.

A flow control device for use in a heat exchange system, including: a housing, a movable valve member and a drive control member, the housing being formed to have a mounting cavity, a first interface and a second interface, while the drive control member includes a control unit, a power output unit, a magnetic element and a detection element; the power output unit provides power to the movable valve member, while the detection element and the control unit are electrically connected, and the magnetic element and the power output unit are mutually assembled and oppositely fixed, the power output unit may drive the magnetic element to rotate; the detection element and the magnetic element are oppositely disposed, the detection element being located within the range of the magnetic field of the magnetic element, the detection element may sense a magnetic pole change of the magnetic element.

An aspect of the disclosure provides a rotation angle detecting device capable of detecting a rotation angle of a rotation body rotatable about a central axis. The rotation angle detecting device includes: a sensor magnet, having multiple magnetic poles provided side-by side in a circumferential direction about the central axis and installed to the rotation body; a magnetic sensor, overlapped with the sensor magnet when viewed in a predetermined first direction and capable of detecting a magnetic field of the sensor magnet; and a pair of magnetic parts, provided to sandwich the magnetic sensor in a second direction intersecting the first direction.