Apparatus and associated methods relate to monitoring health of a system for sensing rotational frequency of a rotatable member. A plurality of magnetic speed probes, each of which is configured to sense the rotational frequency of the rotatable member, are arranged in transmissive proximity with one another. A transmitter-configured one of the plurality of magnetic speed probes includes a signal coupler that couples an electrical signal generated by a radio-frequency signal generator into the inductive coil of the transmitter-configured magnetic speed probe, thereby radiatively transmitting an electromagnetic signal. A speed-probe monitor electrically coupled to each of the plurality of magnetic speed probes determines, based on the coil current sensed by each of the plurality of magnetic speed probes in response to the electromagnetic signal radiatively transmitted, health of the system.

An angular velocity sensor includes an angular velocity sensor element, a drive circuit, a detection circuit, and a reference potential supply circuit. The angular velocity sensor element has a monitor electrode, a drive electrode, a sense electrode, and a weight. The reference potential supply circuit supplies a reference potential to the angular velocity sensor element. The reference potential supply circuit has a first CV converter, a second CV converter, a comparator, and a reference potential adjustment circuit. The first CV converter is connected to the monitor electrode. The second CV converter is connected to the sense electrode. The comparator compares a frequency of a signal being output from the first CV converter with a frequency of a signal being output from the second CV converter, and outputs a signal depending on a result of the comparison.

According to one example implementation, an angle sensor apparatus is provided, including: a sensor arrangement that is configured to respond to a rotational movement of a rotatable object by providing at least two phase-shifted measurement signals, an angle determination device that is configured to take the at least two phase-shifted measurement signals as a basis for determining an angular position, and a difference calculation device that is configured to determine a difference between the angular position determined by the angle determination device and an output from a counter, the counter being configured to be controlled based on the difference.

A controller is used to output a first pulse width modulation signal to a fan connector, and perform a test according to the first pulse width modulation signal and a first fan speed signal so as to determine whether a circuit related to a fan is normal. The fan connector is used to output a second pulse width modulation signal corresponding to the first pulse width modulation signal to the feedback device, and output the first fan speed signal corresponding to a second fan speed signal to the controller. The feedback device is used to generate the second fan speed signal corresponding to the second pulse width modulation signal, and output the second fan speed signal to the fan connector.

An angular velocity sensor includes an angular velocity sensor element, a drive circuit, a detection circuit, and a reference potential supply circuit. The angular velocity sensor element has a monitor electrode, a drive electrode, a sense electrode, and a weight. The reference potential supply circuit supplies a reference potential to the angular velocity sensor element. The reference potential supply circuit has a first CV converter, a second CV converter, a comparator, and a reference potential adjustment circuit. The first CV converter is connected to the monitor electrode. The second CV converter is connected to the sense electrode. The comparator compares a frequency of a signal being output from the first CV converter with a frequency of a signal being output from the second CV converter, and outputs a signal depending on a result of the comparison.

Apparatus and associated methods relate to monitoring health of a system for sensing rotational frequency of a rotatable member. A plurality of magnetic speed probes, each of which is configured to sense the rotational frequency of the rotatable member, are arranged in transmissive proximity with one another. A transmitter-configured one of the plurality of magnetic speed probes includes a signal coupler that couples an electrical signal generated by a radio-frequency signal generator into the inductive coil of the transmitter-configured magnetic speed probe, thereby radiatively transmitting an electromagnetic signal. A speed-probe monitor electrically coupled to each of the plurality of magnetic speed probes determines, based on the coil current sensed by each of the plurality of magnetic speed probes in response to the electromagnetic signal radiatively transmitted, health of the system.

A wheel speed sensor is configured to generate pulses based on teeth that rotate with a wheel passing the wheel speed sensor. A wheel speed module is configured to receive first and second pulses, retrieve from memory a previous compensated wheel speed determined for the second time, determine a measured wheel speed at the first time and a previous measured wheel speed at the second time based on the first and second pulses, and determine a present compensated wheel speed for the first time based on (a) the measured wheel speed at the first time, (b) the previous compensated wheel speed for the second time and (c) a measurement latency of the wheel speed sensor. A control module is configured to actuate an actuator of the vehicle based on the present compensated wheel speed.

According to one example implementation, an angle sensor apparatus is provided, including: a sensor arrangement that is configured to respond to a rotational movement of a rotatable object by providing at least two phase-shifted measurement signals, an angle determination device that is configured to take the at least two phase-shifted measurement signals as a basis for determining an angular position, and a difference calculation device that is configured to determine a difference between the angular position determined by the angle determination device and an output from a counter, the counter being configured to be controlled based on the difference.