Patent ID: 9369800
Filing Date: 2016-06-14
CPC Classification: H04R

Claim Text:
1. An audio circuit for a portable two-way radio device, comprising: an audio power amplifier circuit having an input that is common to a first audio power amplifier and a second audio power amplifier, the first audio power amplifier providing a first output and the second audio power amplifier providing a second output; a first set of series-connected redundant current limiters coupled to a power input of the first audio power amplifier, and a second set of series-connected redundant current limiters coupled a power input of the second audio power amplifier, wherein each of the current limiters limit the electrical current provided to its respective amplifier from a power source to a preselected current level based on an ignition safety level of electrical current; and a speaker including a first speaker coil connected to the first output of the audio power amplifier circuit, and a second speaker coil connected to the second output of the audio power amplifier circuit, each speaker coil having an inductance value that is selected based on the preselected current level to be incapable of storing energy in excess of a preselected energy storage limit that is based on an ignition safety level of energy storage, wherein the first and second speaker coils are separated from each other by a preselected minimum dielectric distance based on a minimum safe voltage rating.