12results about "Transducer protection circuits" patented technology

In examples, a device includes audio amplifier circuitry having an input and an output. The output is configured to couple to a speaker. The device also includes sense circuitry coupled to the output and configured to sense a voltage and a current of an analog audio signal from the audio amplifier circuitry. The current indicates a back electromotive force (EMF) of the speaker. The device also includes processing circuitry coupled to the sense circuitry, which is configured to calculate an impedance of a speaker based on the voltage and the current, compare the impedance to a target impedance, and indicate an operational status of the speaker responsive to the comparison.

This application relates to methods and apparatus for clipping prevention. A driver apparatus for driving a load with an output signal has a switching driver with a switch network and a modulator configured to control the switch network to switch output nodes between different switching voltages with a controlled duty-cycle. A quantizer controller receives a quantizer input signal based on an input signal and a feedback signal and controls the duty-cycle of the switch network. A clipping prevention controller is configured to control a gain applied to the input signal so as to provide limiting of the input signal to avoid clipping, wherein the clipping prevention controller is configured to dynamically control at least one limiting threshold used to determine when to apply limiting of the input signal based on an indication of said quantizer input signal.

A hearing instrument system is proposed, comprising a hearing instrument (1) having a housing (12) and at least one speaker (8) disposed within the housing (12), the speaker being connected to the environment of the housing (12) via a sound conduction channel (14). Furthermore, the hearing instrument system has a controller (6) configured to determine whether at least one initiation condition exists for realizing a cleaning mode of the sound conduction channel (14), and if such initiation condition exists or one of a plurality of possible initiation conditions, to initiate a cleaning mode and, during the cleaning mode, to emit a sound signal with a predetermined waveform having a varying periodic duration through the speaker (8).

A hearing instrument system has a hearing instrument with a housing and at least one loudspeaker arranged in the housing connected to an environment of the housing via a sound conduction channel. The hearing instrument system further has a controller configured to ascertain whether at least one starting condition for initiating a cleaning mode for the sound conduction channel is present. If the or one of multiple, as appropriate, starting conditions is present, initiate the cleaning mode, and during the cleaning mode, output an audio signal with a specified waveform with a varying period using the loudspeaker.

Example techniques may involve controlling a passive radiator. An implementation may include a device receiving, via a network interface, audio content and generating an audio signal representing the audio content. Generating the audio signal involves modifying portions of the audio content to limit excursion of the speaker driver to less than an excursion limit when a forward prediction model indicates that the portions of the audio content are predicted to cause the speaker driver to move beyond the excursion limit. While playing back the generated audio signal via the audio stage, the device detects, via a sensor, clipping of the speaker driver and generates a feedback signal based on the detected clipping of the speaker driver. The device adjusts the forward prediction model based on the generated feedback signal.

A hearing instrument system is described, comprising a hearing instrument (1) with a housing (12) and at least one loudspeaker (8) arranged in the housing (12), which is connected to the environment of the housing (12) via a sound conduction channel (14). Furthermore, the hearing instrument system includes a controller (6) configured to determine whether at least one start condition for initiating a cleaning mode for the sound conduction channel (14) is present, to initiate the cleaning mode if the start condition or one of possibly several is present, and to emit a tone signal in the form of a chirp via the loudspeaker (8) during the cleaning mode.

An amplifier power attenuator utilizes an amplified audio feedback signal from an audio amplifier (which is driving a loudspeaker), along with a user-set impedance and a maximum voltage set-point reflective of the operational parameters of the loudspeaker, to attenuate an audio signal prior to amplification thereby preventing damage to the loudspeaker. The impedance of a variable impedance optocoupler is changed to adjust the attenuation of the audio signal to one of a plurality of predetermined attenuation levels responsive to an error between a voltage level of the feedback signal and the maximum voltage set-point. The error is reflected in a counter value having a linear or non-linear relationship with the error dependent upon a magnitude of the error; the counter value is assessed against a plurality of target values associated with respective ones of the predetermined attenuation levels to identify the attenuation to be applied to the audio signal.

A system filters an audio signal includes a signal input, a signal output, a scaling path, a limiter path, and a delay path. The signal input receives an input signal and the signal output for outputs an output signal. The limiter path is parallel to the scaling path. The delay path is between the signal input and the signal output parallel to the scaling path and the limiter path. The scaling path forms a scaling signal by forming a mean value of the input signal and using non-linear signal processing. The limiter path includes a low-pass characteristic and changes a phase of the input signal of the system in a manner dependent on frequency in order to generate a limiter signal. The system impresses the limiter signal that is scaled using the scaling signal onto a delay signal of the delay path in order to generate the output signal.

A hearing protection apparatus for disrupting wireless transmissions near the ears of a user while protecting the ears from noise includes an ear covering assembly comprising a headband and a pair of cups which is positionable to cover the ears of a user. A jammer circuit is provided which transmits a jamming signal toward the ears of the user to disrupt wireless communication near the ears of the user.

A hearing instrument system is described, comprising a hearing instrument (1) with a housing (12) and at least one loudspeaker (8) arranged in the housing (12), which is connected to the environment of the housing (12) via a sound conduction channel (14). Furthermore, the hearing instrument system includes a controller (6) configured to determine whether at least one start condition for initiating a cleaning mode for the sound conduction channel (14) is present, to initiate the cleaning mode if the start condition or one of possibly several is present, and to emit an audio signal with a predetermined waveform and varying period via the loudspeaker (8) during the cleaning mode.

The voice coil driving system includes a magnetic circuit 21, 22, 23, a voice coil 10 and a driving circuit 30. The voice coil 10 is suspended in the air gap and includes a plurality of voice coil se

To provide "an audio system" in which an overheated speaker can be quickly cooled.SOLUTION: In an audio system, when overheating of a speaker 2 is detected, a controller 9 controls a first selector 3 and a second selector 6 to input an audio signal output by an audio source device 1 to a cooling processing section 4 and causes output of the cooling processing section to be output to the speaker 2. In the cooling processing section 4, a mixer 46 mixes an audio signal obtained by removing, by a high-pass filter 41, a low-frequency component from the audio signal input to the cooling processing section 4 with a cooling signal at an infrasonic frequency generated by a cooling signal generator 42 and adjusted with a gain by a gain adjuster 44, and the mixed signal is output from the cooling processing section 4 via a nonlinear inverse filter 47. A gain setting section 45 of the cooling processing section 4 sets the gain of the gain adjuster 44 such that power of the cooling signal output from the gain adjuster 44 matches power of the low-frequency component of the audio signal input to the cooling processing section 4, the component being extracted by a low-pass filter 43.SELECTED DRAWING: Figure 1