| 摘要 |
An amplified microphone assembly for increasing the intelligibility of transmitted speech and including a microphone element, an audio amplifier, an auxiliary power supply and a push-to-talk switch. The microphone element converts an audio signal to an electrical signal while the audio amplifier amplifies the electrical signal. The auxiliary power supply supplies power to the audio amplifier when the push-to-talk switch is actuated, at which time an audio signal from the amplifier is sent to a radio transceiver. The power supply is chargeable and includes a charging circuit for charging the power supply. A connecting cable connects the microphone assembly to a transceiver and includes an audio lead and two push-to-talk leads which place the transceiver in the transmit mode when the push-to-talk switch is actuated. The charging circuit is connected across the push-to-talk leads and utilizes the voltage drop therebetween, as generated in the transceiver when the leads are not connected in the receive mode to, in turn, recharge the power supply. In the first embodiment of the invention the power supply includes a rechargeable battery and in the second embodiment of the invention the power supply includes a low-leakage high-capacity capacitor.
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