| CPC H04R 3/00 (2013.01) [H04R 2499/11 (2013.01); H04W 4/10 (2013.01)] | 5 Claims |
|
1. A dual-purpose circuit for sound emission and sound pickup applied to an individual speaker unit, comprising:
a communication interface module;
an electronic power switch module;
a filter;
a signal gain module;
a double-pole double-throw switch module; and
a sound-emission unit interface module;
wherein the communication interface module comprises a microphone interface unit, a speaker interface unit and a reception state switching interface unit;
a positive pole of the microphone interface unit is connected to the electronic power switch module, the signal gain module and the double-pole double-throw switch module;
the electronic power switch module, the filter and the signal gain module are connected in sequence;
a grounding terminal of the signal gain module is connected to ground;
a first normally-closed terminal and a second normally-closed terminal of the double-pole double-throw switch module are connected to the signal gain module, a first common terminal and a second common terminal of the double-pole double-throw switch module are connected to the sound-emission unit interface module, and a grounding terminal of the double-pole double-throw switch module is connected to ground; and
a negative pole of the microphone interface unit is connected to ground;
a negative pole of the speaker interface unit is connected to a first normally-open terminal of the double-pole double-throw switch module; and a positive pole of the speaker interface unit is connected to a second normally-open terminal of the double-pole double-throw switch module;
a positive pole of the reception state switching interface unit is connected to an enable terminal of the double-pole double-throw switch module and an enable terminal of the electronic power switch module; and
a negative pole of the reception state switching interface unit is connected to ground;
the sound-emission unit interface module is configured to connect a low-impedance speaker unit;
the reception state switching interface unit is connected to a push-to-talk (PTT) switch;
the PTT switch is configured to control the electronic power switch module and the double-pole double-throw switch module, such that a working state of the low-impedance speaker unit is switched between a sound pickup state and a sound emission state;
the PTT switch is mechanical;
the working state of the low-impedance speaker unit is switched through steps of:
controlling, by the PTT switch, the electronic power switch module to be in a closed state, so that the signal gain module is turned on, and synchronously pulling down the enable terminal of the double-pole double-throw switch module to allow the first common terminal and the second common terminal of the double-pole double-throw switch module to be respectively connected to the first normally-closed terminal and the second normally-closed terminal of the double-pole double-throw switch module, so that the low-impedance speaker unit is switched to the sound pickup state; and
controlling, by the PTT switch, the electronic power switch module to be in an open state, so that the signal gain module is turned off, and synchronously pulling up the enable terminal of the double-pole double-throw switch module to allow the first common terminal and the second common terminal of the double-pole double-throw switch module to be respectively connected to the first normally-open terminal and the second normally-open terminal of the double-pole double-throw switch module, so that the low-impedance speaker unit is switched to the sound emission state;
the electronic power switch module is a P-channel metal-oxide-semiconductor field effect transistor (PMOS);
in a first case where the PTT switch is pressed to connect to ground, the electronic power switch module is turned on to power the signal gain module, and the enable terminal of the double-pole double-throw switch module is pulled down synchronously, so that the first common terminal and second common terminal of the double-pole double-throw switch module are respectively connected to the first normally-closed terminal and the second normally-closed terminal of the double-pole double-throw switch module; the low-impedance speaker unit adopts a dynamic unit, and is connected to the sound-emission unit interface module, such that when an external sound pressure acts on the dynamic unit, a voice coil is driven to move to generate an alternating signal;
the alternating signal is transmitted to the signal gain module as a differential signal source, and is converted into an audio signal in the signal gain module;
the audio signal is amplified in the signal gain module by means of signal gain, then transmitted to the microphone interface unit at an interphone interface sequentially through a first resistor and a first capacitor, thus realizing a working principle of the dynamic speaker as a sound pickup unit; and
in a second case where the PTT switch is not pressed, the electronic power switch module is turned off to disconnect the power supply of the signal gain module, the signal gain module loses a signal gain amplification function, and the enable terminal of the double-pole double-throw switch module synchronously is pulled up through a second resistor, so that the first common terminal and second common terminal of the double-pole double-throw switch module are respectively connected to the first normally-open terminal and the second normally-open terminal of the double-pole double-throw switch module, and are disconnected from the first normally-closed terminal and the second normally-closed terminal of the double-pole double-throw switch module, that is, the low-impedance speaker unit is connected to the first normally-open terminal and the second normally-open terminal of the double-pole double-throw switch module via the first common terminal and the second common terminal of the double-pole double-throw switch module, and a signal is transmitted to the speaker interface unit at the interphone interface via a third resistor, thus realizing a working principle of the dynamic speaker as the sound-emission unit.
|