Abstract: Embodiments described herein provide methods and apparatus for predicting the excursion of a transducer. The method comprises determining whether an input signal to the transducer is a periodic signal; and responsive to determining that the input signal is a periodic signal, calculating the predicted excursion based on a direct current (“DC”) offset associated with the transducer.

Abstract: This application relates to methods and apparatus for loudspeaker protection. A loudspeaker protection system receives a digital audio signal comprising a plurality of samples at an input node. A delay block delays the digital audio signal and a gain block applies a controlled gain to the delayed digital audio signal. An excursion predictor is configured to receive a version of the audio signal from the signal path upstream of the delay block and determine a predicted excursion for a loudspeaker based on the audio signal. A gain controller controls a gain setting of the gain block in response to the predicted excursion and a first loudspeaker impulse response model and a predetermined excursion limit. The gain controller is configured to determine at least one gain setting {ga gi} to be applied to a set of samples {Va . . .

Abstract: Methods and Apparatus for estimating a temperature of an electromechanical transducer. The method comprising receiving an audio signal (901); providing an output signal to the electromechanical transducer, based on the audio signal (902); and determining whether a first magnitude of the audio signal in a first frequency band is above a magnitude threshold (903). In response to the first magnitude being above or equal to the magnitude threshold, calculating a first impedance of the electromechanical transducer based on measurements of a first voltage and a first current of the electromechanical transducer within the first frequency band (905), and estimating the temperature of the electromechanical transducer based on the first impedance (907).

Abstract: Embodiments described herein provide a method in a thermal model based estimator and a thermal model based estimator for estimating a temperature of a transducer. The method comprises receiving a first signal wherein the first signal is representative of an impedance across the transducer; receiving an indication of a current across the transducer; determining an estimated thermal power based on the indication of the current and an estimated temperature signal, determining, based on the estimated thermal power, the estimated temperature signal using a thermal model of the transducer comprising states defined by a thermal state vector; comparing the first signal with a second signal derived from the estimated temperature signal; updating the thermal state vector of the thermal model based on the comparison; and; outputting the estimated temperature signal.

Abstract: This application describes methods and apparatus for loudspeaker protection. A loudspeaker protection system (100) is described having a first frequency band-splitter (102) for splitting an input audio signal (Vin) into a plurality of audio signals (v1, v2 . . . , vn) in different respective frequency bands (?1, ?2 . . . , ?n). A first gain block (103) is configured to apply a respective frequency band gain (g1, g2 . . . , g3) to each of the audio signals in the different respective frequency bands and a gain controller (107, 108, 109) is provided for controlling the respective band gains. A displacement modeller (104, 105) determines a plurality of displacement signals (x1, x2 . . . , xn) based on the input audio signal (Vin) and a displacement model (104a) where each displacement signal corresponds to a modelled cone displacement for the loudspeaker for one of said different respective frequency bands.

Abstract: This application describes methods and apparatus for loudspeaker protection. A loudspeaker protection system (1100) is described having a first frequency band-splitter (102) for splitting an input audio signal (Vin) into a plurality of audio signals (v1, v2 . . . ,vn) in different respective frequency bands (?1, ?2 . . . ??). A first gain block (103) is configured to apply a respective frequency band gain (gt1, gt2 . . . ,gt3) to each of the audio signals in the different respective frequency bands and a gain controller (109; 1101) is provided for controlling the respective band gains. A thermal controller (1101) determines, for each of a plurality of the different respective frequency bands, a power dissipation for the loudspeaker in that frequency band and also determines a respective thermal gain setting based on the determined power dissipation for that frequency band. The gain controller is configured to control the respective frequency band gains based on the thermal gain settings.

Abstract: This application relates to methods and apparatus for loudspeaker protection. A loudspeaker protection system receives a digital audio signal comprising a plurality of samples at an input node. A delay block delays the digital audio signal and a gain block applies a controlled gain to the delayed digital audio signal. An excursion predictor is configured to receive a version of the audio signal from the signal path upstream of the delay block and determine a predicted excursion for a loudspeaker based on the audio signal. A gain controller controls a gain setting of the gain block in response to the predicted excursion and a first loudspeaker impulse response model and a predetermined excursion limit. The gain controller is configured to determine at least one gain setting {ga gi} to be applied to a set of samples {Va . . .

Abstract: Embodiments described herein provide methods and apparatus for predicting the excursion of a transducer. The method comprises determining whether an input signal to the transducer is a periodic signal; and responsive to determining that the input signal is a periodic signal, calculating the predicted excursion based on a direct current (“DC”) offset associated with the transducer.

Abstract: Embodiments described herein provide a method in a thermal model based estimator and a thermal model based estimator for estimating a temperature of a transducer. The method comprises receiving a first signal wherein the first signal is representative of an impedance across the transducer; receiving an indication of a current across the transducer; determining an estimated thermal power based on the indication of the current and an estimated temperature signal, determining, based on the estimated thermal power, the estimated temperature signal using a thermal model of the transducer comprising states defined by a thermal state vector; comparing the first signal with a second signal derived from the estimated temperature signal; updating the thermal state vector of the thermal model based on the comparison; and; outputting the estimated temperature signal.

Abstract: This application relates to methods and apparatus for loudspeaker protection. A loudspeaker protection system (100) receives a digital audio signal comprising a plurality of samples at an input node (IN). A delay block (15) delays the digital audio signal and a gain block (14) applies a controlled gain to the delayed digital audio signal. An excursion predictor (12) is configured to receive a version of the audio signal from the signal path upstream of the delay block and determine a predicted excursion for a loudspeaker based on the audio signal. A gain controller (23) controls a gain setting (g) of the gain block in response to the predicted excursion and a first loudspeaker impulse response model and a predetermined excursion limit. The gain controller (23) is configured to determine at least one gain setting {ga gi} to be applied to a set of samples {Va . . .

Abstract: Methods and Apparatus for estimating a temperature of an electromechanical transducer. The method comprising receiving an audio signal (901); providing an output signal to the electromechanical transducer, based on the audio signal (902); and determining whether a first magnitude of the audio signal in a first frequency band is above a magnitude threshold (903). In response to the first magnitude being above or equal to the magnitude threshold, calculating a first impedance of the electromechanical transducer based on measurements of a first voltage and a first current of the electromechanical transducer within the first frequency band (905), and estimating the temperature of the electromechanical transducer based on the first impedance (907).

Abstract: This application relates to methods and apparatus for loudspeaker protection. A loudspeaker protection system (100) receives a digital audio signal comprising a plurality of samples at an input node (IN). A delay block (15) delays the digital audio signal and a gain block (14) applies a controlled gain to the delayed digital audio signal. An excursion predictor (12) is configured to receive a version of the audio signal from the signal path upstream of the delay block and determine a predicted excursion for a loudspeaker based on the audio signal. A gain controller (23) controls a gain setting (g) of the gain block in response to the predicted excursion and a first loudspeaker impulse response model and a predetermined excursion limit. The gain controller (23) is configured to determine at least one gain setting {ga gi} to be applied to a set of samples {Va . . .

Abstract: This application relates to methods and apparatus for loudspeaker protection. A loudspeaker protection system (100) receives a digital audio signal comprising a plurality of samples at an input node (IN). A delay block (15) delays the digital audio signal and a gain block (14) applies a controlled gain to the delayed digital audio signal. An excursion predictor (12) is configured to receive a version of the audio signal from the signal path upstream of the delay block and determine a predicted excursion for a loudspeaker based on the audio signal. A gain controller (23) controls a gain setting (g) of the gain block in response to the predicted excursion and a first loudspeaker impulse response model and a predetermined excursion limit. The gain controller (23) is configured to determine at least one gain setting {ga gi} to be applied to a set of samples {Va . . .

Abstract: This application describes methods and apparatus for loudspeaker protection. A loudspeaker protection system (100) is described having a first frequency band-splitter (102) for splitting an input audio signal (Vin) into a plurality of audio signals (v1, v2 . . . , vn) in different respective frequency bands (?1, ?2 . . . , ?n). A first gain block (103) is configured to apply a respective frequency band gain (g1, g2 . . . , g3) to each of the audio signals in the different respective frequency bands and a gain controller (107, 108, 109) is provided for controlling the respective band gains. A displacement modeller (104, 105) determines a plurality of displacement signals (x1, x2 . . . , xn) based on the input audio signal (Vin) and a displacement model (104a) where each displacement signal corresponds to a modelled cone displacement for the loudspeaker for one of said different respective frequency bands.

Abstract: This application describes methods and apparatus for loudspeaker protection. A loudspeaker protection system (1100) is described having a first frequency band-splitter (102) for splitting an input audio signal (Vin) into a plurality of audio signals (v1, v2 . . . ,vn) in different respective frequency bands (?1, ?2 . . . ??). A first gain block (103) is configured to apply a respective frequency band gain (gt1, gt2 . . . ,gt3) to each of the audio signals in the different respective frequency bands and a gain controller (109; 1101) is provided for controlling the respective band gains. A thermal controller (1101) determines, for each of a plurality of the different respective frequency bands, a power dissipation for the loudspeaker in that frequency band and also determines a respective thermal gain setting based on the determined power dissipation for that frequency band. The gain controller is configured to control the respective frequency band gains based on the thermal gain settings.

Abstract: This application relates to methods and apparatus for thermal protection of a loudspeaker (102). A controller (106) is configured to generate a control signal (Gmod) for modulating the gain of a signal processing chain (101) that drives the loudspeaker. The controller is configured such that the control signal is generated as a function of each of: an indication of voice coil temperature of the loudspeaker (TVC); an indication of power dissipation in the voice coil of the loudspeaker (PVC); and an indication of a reservoir temperature (Tres) of a thermal reservoir for heat flow from the voice coil. The reservoir temperature may be an ambient temperature of the environment or a temperature of a component of the loudspeaker or apparatus that acts as a heat sink.

Abstract: This application relates to methods and apparatus for thermal protection of a loudspeaker (102). A controller (106) is configured to generate a control signal (Gmod) for modulating the gain of a signal processing chain (101) that drives the loudspeaker. The controller is configured such that the control signal is generated as a function of each of: an indication of voice coil temperature of the loudspeaker (TVC); an indication of power dissipation in the voice coil of the loudspeaker (PVC); and an indication of a reservoir temperature (Tres) of a thermal reservoir for heat flow from the voice coil. The reservoir temperature may be an ambient temperature of the environment or a temperature of a component of the loudspeaker or apparatus that acts as a heat sink.

Abstract: This application relates to methods and apparatus for loudspeaker protection. A loudspeaker protection system (100) receives a digital audio signal comprising a plurality of samples at an input node (IN). A delay block (15) delays the digital audio signal and a gain block (14) applies a controlled gain to the delayed digital audio signal. An excursion predictor (12) is configured to receive a version of the audio signal from the signal path upstream of the delay block and determine a predicted excursion for a loudspeaker based on the audio signal. A gain controller (23) controls a gain setting (g) of the gain block in response to the predicted excursion and a first loudspeaker impulse response model and a predetermined excursion limit. The gain controller (23) is configured to determine at least one gain setting {ga gi} to be applied to a set of samples {Va . . .

Abstract: A system is disclosed for controlling motor switching in a sensorless BLDC motor having a set of three stator windings. A controller unit includes a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage having a plurality of switches receives a control signal from the control signal generator and a power signal from a power source. The power stage drives two windings of the set of three stator windings with an asymmetric pulse width modulation signal and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit also communicates with the power stage to change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses a threshold.

Abstract: The system and method disclose for the controlling of motor switching. The system includes a controller unit having a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage has a plurality of switches and receives a control signal from the control signal generator and a power signal from a power source. The power stage drives two windings of the set of three stator windings with a multi-state pulse and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit communicates with the power stage to change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses a threshold.