Abstract: A brushless DC motor system, includes a single coil brushless DC motor and a driver for driving the single coil brushless DC motor. The brushless DC motor system has a maximum time constant ?max. The driver comprises a control unit which is adapted for driving the brushless DC motor at a constant speed and at a variable speed by applying a PWM driving signal to the coil of the brushless DC motor with a PWM frequency larger than a ratio defined by a constant/?max wherein the ratio is such that a current through the coil is always bigger than a pre-defined undercurrent limit.

Abstract: A method for braking a single coil BLDC motor includes iterating a plurality of times through a sequence of: a braking state which lasts a braking period; and a high impedance state which lasts a cool down period. The current runs through the single coil during the braking state and no current runs through the single coil during the high impedance state. The transiting from the braking state to the high impedance state is done when the motor operates in generator mode.

Abstract: A semiconductor device comprising a passive magnetoelectric transducer structure adapted for generating a charge via mechanical stress caused by a magnetic field. The first transducer structure has a first terminal electrically connectable to the control terminal of an electrical switch, and having a second terminal electrically connectable to the first terminal of the electrical switch for providing a control signal for opening/closing the switch. The switch may be a FET. A passive magnetic switch using a magnetoelectric transducer structure. Use of a passive magnetoelectric transducer structure for opening or closing a switch without the need for an external power supply.

Abstract: A motor driver for driving a rotor of a single coil motor in a clockwise or counterclockwise rotation direction concerning a stator of the single coil motor is adapted for generating a position signal which is representative for the angular position of the rotor regarding the stator and comprises a controller which comprises a direction input to define the rotation direction of the rotor, and which is adapted for generating a driving signal for rotating the rotor in the defined rotation direction, wherein the driving signal is based on the position signal and is based on a signal indicative for an electrical lead angle wherein the signal indicative for the electrical lead angle is set such that the total lead angle is positive in both rotation directions of the rotor.

Abstract: A sensor device comprises a sensor connected to a first signal and responsive to an external field to produce a sensor signal, a test device connected to a second signal and electrically connected in series with the sensor by an electrical test connection providing a test signal, and a monitor circuit electrically connected to the first, second and test signals. The monitor circuit comprises a processing circuit and a determination circuit. The processing circuit is responsive to the test signal and a predetermined processing value to form a processing output signal. The determination circuit is responsive to the processing output signal to determine a diagnostic signal. A sensor circuit responsive to the sensor signal provides a sensor device signal responsive to the external field.

Abstract: A Brushless Direct Current (BLDC) motor controller comprises a first terminal for applying a first voltage and a second terminal for applying a second voltage to obtain a driving current for driving a BLDC motor. The BLDC motor controller comprises a remote control unit which is adapted for monitoring a signal which is indicative for a current through at least the first or the second terminal. The BLDC motor controller is adapted for increasing the monitored current by applying an additional current. The additional current is different from zero if the motor is rotating. The BLDC motor controller is adapted for determining whether the motor is rotating or not, based on the monitored signal.

Abstract: A sensor device comprises a sensor arranged to sense and convert the physical quantity into an electrical quantity and to output an electrical signal representative of the electrical quantity. A voltage limiter receives an input signal related to a supply voltage providing power to the sensor device and to output a voltage signal. The voltage signal has a limited value if the input voltage exceeds a voltage saturation threshold value. A voltage-to-current converter converts the voltage signal output by the voltage limiter to a supply current of a first value, thereby forming a first supply current state. A switch switches between the first supply current state and at least a second supply current state wherein the supply current is substantially independent of the supply voltage. Current generation means provides the supply current of the predetermined second value to form the second supply current state.

Abstract: A method for diagnosing errors in the correct operation of a sensor system. A positive signal amplifier saturation threshold value and a negative signal amplifier saturation threshold value less than the positive signal amplifier saturation threshold value are provided, and at least one signal comparator threshold value. A current value of a first amplified input signal at a first time is provided and a current value of a second amplified input signal obtained at a second time later than the first time, but in the same measurement cycle. The measured values of the first and second amplified input signal are compared to the current signal comparator threshold value. A new output state is determined via the measured first and second amplified input signals. From a previous comparison of the first and second amplified input signal a current output state is provided, from which an expected new output state is determined.

Abstract: A solid state circuit includes a main and a floating circuit including: a first driver for generating a differential driver signal derived from a driver signal; a modulator configured for modulating a modulator signal with another signal to obtain a differential control signal; the floating circuit comprising: a floating power supply comprising at least one rectifier configured for generating a floating supply voltage (VDDF) and a floating ground voltage (VSSF) from the differential driver signal; a demodulator configured for demodulating the differential control signal and for passing the demodulated signal to an output switch; the output switch comprising a first output node and a second output node and at least one transistor configured for opening or closing an electrical path under control of the demodulated signal.

Abstract: A sensor circuit comprises a sensor adapted to sense a physical quantity and to produce a sensor output signal. A sensor-offset correction block is arranged to receive a signal indicative of a supply voltage applied to the sensor circuit and to generate a compensation signal based on the signal indicative of the supply voltage and on a quantity indicative of a state of the sensor circuit. A combiner is adapted to combine the sensor output signal with the compensation signal, thereby obtaining a compensated signal.

Abstract: A position sensor for determining the position of an object, comprising at least one sensing element to transduce a time-varying external signal into an electrical signal; at least one comparator circuit adapted to perform a thresholding operation on the electrical signal being characterized by a hysteresis curve; the position sensor is adapted to provide information relating to the last crossed to store it at least while the position sensor is in an inactive mode and to restore the information to obtain a selected threshold when it is switched from inactive to active mode; and configured such that a transition in an output signal is generated by the thresholding operation if the selected threshold is crossed by the electrical signal and configured to change the selected threshold after it was crossed by the electrical signal.

Abstract: A sensor device includes a sensor for sensing amounts of a physical quantity, such as an environmental attribute, and providing sensor signals formed in response to the sensed physical quantity. A diagnostic test circuit provides multiple diagnostic test signals each representing a desired response to a particular amount of the physical quantity. A signal circuit selects the sensor signal or the diagnostic test signal and forms a signal circuit output. A reference circuit provides a calibrated reference signal corresponding to a threshold amount of the physical quantity. A comparator receives and compares the calibrated reference signal and the signal circuit output to form a comparison signal. A control circuit controls the signal circuit, reference circuit, and diagnostic test circuit and receives the comparison signal to output a sensor device sensor signal or sensor device diagnostic signal.

Abstract: A brushless DC motor driver for driving a brushless DC motor which comprises at least one coil wherein the control unit is adapted for applying a PWM driving signal to the at least one coil of the brushless DC motor such that a current through the at least one coil is always bigger than a pre-defined undercurrent limit.

Abstract: A sensor device comprises a sensor connected to a first signal and responsive to an external field to produce a sensor signal, a test device connected to a second signal and electrically connected in series with the sensor by an electrical test connection providing a test signal, and a monitor circuit electrically connected to the first, second and test signals. The monitor circuit comprises a processing circuit and a determination circuit. The processing circuit is responsive to the test signal and a predetermined processing value to form a processing output signal. The determination circuit is responsive to the processing output signal to determine a diagnostic signal. A sensor circuit responsive to the sensor signal provides a sensor device signal responsive to the external field.

Abstract: A method for controlling a single coil brushless DC motor, the method comprising at least a first EHP sequence which comprises: driving the motor using a driving signal during a torque generating period, to accelerate the motor, such that during a subsequent generator mode period a phase current goes in generator mode; driving the motor during the generator mode period using a generator mode signal, which allows the phase current to be in generator mode; monitoring the phase current during the generator mode period thereby obtaining phase current information; and determining parameters of a next EHP sequence based on the obtained phase current information.

Abstract: A method for controlling a single-coil BLDC motor, the method comprising: monitoring a signal indicative of a time derivative of a phase current through the coil of the BLDC motor during at least one commutation cycle; determining a first moment of the at least one commutation cycle such that at the first moment the absolute value of the time derivative of the phase current is smaller than or equal to a slope threshold; determining a rising edge of a driving signal in a commutation cycle, based on the first moment of that commutation cycle and/or based on the first moment of at least one earlier commutation cycle, and/or determining a falling edge of the driving signal in that commutation cycle based on the first moment of at least one earlier commutation cycle; driving the single-coil BLDC motor using the driving signal.

Abstract: A single phase motor drive circuit for driving a single phase motor, comprising: a timer unit for receiving a sensor signal indicative of an angular position of a rotor, and for providing a timing signal in phase with the sensor signal; a waveform generator for generating an waveform for energizing the motor, the waveform generator being adapted for receiving the timing signal and at least one configurable setting (Soff), and for generating the waveform based thereon; a configuration unit adapted for receiving a first input signal indicative of a desired motor speed and a second input signal (Vbat) indicative of the supply voltage, and for determining the configurable setting based on the input signals, and for providing the setting to the waveform generator to dynamically configure the waveform generator. A method of driving a single phase motor.

Abstract: A motordriver for controlling a brushless DC motor, comprises: an output driver for controlling phase commutation of a power stage; the motordriver can be powered in a pulsed way having a PWM ON and OFF period; a position module for monitoring a position and/or speed of a rotor; at least a part of the position module remains active during the PWM OFF period; a power module configured for powering the active part during the PWM OFF period, comprising an energy storage medium and a blocking module configured such that during the PWM ON period the energy storage medium can be charged by the power supply, and such that the blocking module can block current flowing back to the power supply and block current flowing from the energy storage medium to the motor during the PWM OFF period.

Abstract: A method of starting and/or driving a fan assembly, the fan assembly comprising a BLDC motor having one or more coils, and a bearing comprising a lubricant. The method comprises performing a special action for intentionally heating up the one or more coils and thereby indirectly heating up the lubricant. The method may comprise measuring a temperature of the bearing, or measuring a value related to said temperature, and performing the special action only if said temperature is below a certain threshold temperature. Performing the special action comprises setting an off-time to a first predefined value and setting an on-time to a second predefined value, the first and second predefined value having a first ratio. Starting the motor comprises setting the off-time to a third value and setting the on-time to a fourth predefined value, the third and fourth predefined value having a second ratio larger than the first ratio.

Abstract: Method of driving a single-coil motor having a stator and a rotor and a coil, comprising the steps of: monitoring a position signal and determining when said signal passes a first threshold; b) providing control signals for energizing the coil; c) a predefined period later, providing control signals for stopping or reducing the energization of the coil; d) monitoring a second signal indicative of the coil current, and determining a third time when said signal passes a second threshold level; and monitoring the first signal, and determining a fourth time when said signal passes a third threshold level; e) updating the prediction period; f) repeating steps b) to e). A driver circuit adapted for performing such method. A system comprising such driver circuit.