Loudspeaker protection systems and methods

摘要

Methods and systems for thermal protection of a voice coil of a loudspeaker. The method involves driving the loudspeaker based on an input signal received at an input terminal and monitoring both a voltage applied to the voice coil and a current flowing through the voice coil. From the monitored voltage and current, an estimate of temperature of the voice coil and an estimate of power dissipation in the voice coil is determined. The method includes estimating the voice coil resistance based on the monitored voltage and current and at least the estimate of temperature is determined based the estimate of resistance. A gain control signal for modulating a gain applied to the input signal is generated as a function of both the estimate of temperature of the voice coil and the estimate of power dissipation in the voice coil. This means that high power dissipation, which would over long periods lead to overheating, can nevertheless be permitted when the voice coil temperature is low enough, while at high voice coil temperatures any gain modulation applied for thermal protection can be reduced if the power dissipation level drops.

主权项

1. A method of thermal protection of a voice coil of a loudspeaker comprising:
driving said loudspeaker based on an input signal received at an input terminal monitoring both a voltage applied to said voice coil and a current flowing through said voice coil; determining both an estimate of temperature of said voice coil and an estimate of power dissipation in said voice coil based on said monitored voltage and current, wherein at least said estimate of temperature is determined based on an estimate of resistance of said voice coil and wherein said estimate of voice coil resistance is determined based on said monitored voltage and current; and generating a gain control signal for modulating a gain applied to said input signal within a signal path between said input terminal and said loudspeaker for thermal protection, wherein said gain control signal is generated as a function of both said estimate of temperature of said voice coil and said estimate of power dissipation in said voice coil.