Interphone audio circuit and interphone
By incorporating an earphone jack design and audio detection circuit into the walkie-talkie, the problems of miniaturization and audio channel fault detection were solved, resulting in improved volume and user experience.
Patent Information
- Application Number
- CN202423203573.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2034-12-25
AI Technical Summary
Existing walkie-talkies, in their miniaturization design, require two earpieces, which take up a lot of space and cannot meet the miniaturization requirements. At the same time, they cannot guarantee the volume of the external earpiece speaker or detect audio channel faults in a timely manner.
The design employs a single headphone jack, which simplifies the walkie-talkie's audio circuitry through a virtual ground wire and audio detection circuit. This ensures that the external headphone speaker receives sufficient volume and can detect the audio channel connection status, enabling timely fault detection.
It achieves the miniaturization requirement of walkie-talkies while ensuring the volume of the external headphone speaker and can promptly detect audio channel faults, thus improving the user experience.
Smart Images
Figure CN223600000U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to intercom field, concretely relates to an intercom audio frequency circuit and intercom. BACKGROUND
[0002] In order to facilitate user operation and guarantee the privacy of communication, the intercom usually sets the earphone interface connected with earphone wire. In the prior art, the commonly used scheme is to set two earphone seats on the intercom, one is connected with loudspeaker, and one is connected with microphone, as shown in the following figure. Figure 1 Figure 1 In the figure, USB_D and USB_D+ are data communication interfaces, used for intercom writing frequency function, MIC is microphone audio input interface, EXT_SPK+ and SPK- are loudspeaker output interfaces, in addition, the grounding interface connected with host ground net is needed, that is, a total of 6 pins are needed. When the intercom needs to be miniaturized, the scheme occupies too much space, and cannot satisfy the demand of miniaturization. SUMMARY
[0003] The utility model provides an intercom audio frequency circuit and intercom, only uses one earphone seat, can satisfy the demand of intercom miniaturization, can also make the external earphone wire loudspeaker obtain enough loudness, and can detect the connection state of audio frequency channel, discovers the fault in time, and promotes user experience.
[0004] The utility model realizes the following technical scheme:
[0005] The intercom audio circuit comprises a control module, an earphone seat, an audio power amplifier, an intercom microphone, an intercom loudspeaker, a microphone control circuit and an audio detection circuit, the first output end of the audio power amplifier is connected with the fourth pin of the earphone seat, the second output end is connected with the first pin of the earphone seat, the first pin of the intercom loudspeaker is connected with the second output end of the audio power amplifier and the first pin of the earphone seat respectively, the second pin is connected with the fifth pin of the earphone seat, the first pin of the intercom microphone is connected with the second pin of the earphone seat, the first pin of the earphone seat is used as a virtual ground, when the external earphone line is connected, the positive electrode of the microphone of the external earphone line is connected with the second pin of the earphone seat, the negative electrode is connected with the first pin of the earphone seat, one pin of the loudspeaker of the external earphone line is connected with the first pin of the earphone seat, the other pin is connected with the fourth pin of the earphone seat, the microphone control circuit is connected with the control module, the microphone and the first pin of the earphone seat respectively, so as to control the intercom microphone or the earphone microphone to work, when the external earphone line is connected, the external earphone line separates the contacts between the fourth pin and the fifth pin of the earphone seat, so that the intercom loudspeaker stops working, the audio detection circuit is connected with the first output end of the audio power amplifier, the fourth pin of the earphone seat and the control module respectively, so as to judge whether the audio power amplifier is disconnected with the earphone seat, thus, the earphone interface is realized only by using one earphone seat, the problem that the pin of one earphone seat is not enough is solved, the demand of miniaturization of the intercom is met, the loudspeaker of the external earphone line can obtain a large enough volume, the connection state of the audio channel can be detected, the fault can be found in time, and the user experience is improved.
[0006] Further, the control module is a microprocessor.
[0007] Further, the microphone control circuit comprises a first triode and a second triode, the base of the first triode is connected with the first I / O port of the microprocessor, the collector is connected with the second pin of the intercom microphone, and the emitter is grounded, the base of the second triode is connected with the second I / O port of the microprocessor, the collector of the second triode is connected with the first pin of the earphone seat, and the emitter of the second triode is grounded through the fifth resistor, so that the intercom microphone or the microphone of the external earphone line can be effectively controlled to work, and the circuit is simple and reasonable.
[0008] Further, the audio detection circuit comprises a direct current power supply, a first resistor, a second resistor and a third resistor connected in series, and a first capacitor, one end of the first resistor is connected with the AD sampling end of the microprocessor, the other end of the first resistor is also connected with the first output end of the audio power amplifier and the fourth pin of the earphone seat, one end of the third resistor is connected with the direct current power supply, the other end of the third resistor is connected with one end of the first capacitor, and the other end of the first capacitor is grounded, so that whether the audio channel is connected can be effectively detected, and the circuit is simple and reasonable.
[0009] Further, it further comprises an electrolytic, the positive electrode is connected with the second output end of the audio power amplifier, and the negative electrode is connected with the fourth pin of the earphone seat.
[0010] Further, the fourth resistor has one end connected with the first pin of the earphone seat and the other end grounded.
[0011] Further, the third pin of the earphone seat is a communication pin.
[0012] The utility model discloses still through following technical schemes realizes:
[0013] A intercom comprises the audio circuit as any one of the above. BRIEF DESCRIPTION OF DRAWINGS
[0014] The utility model will be further explained in detail in connection with the drawings.
[0015] Figure 1 The circuit schematic diagram of the prior art with two earphone seats is provided.
[0016] Figure 2 The circuit schematic diagram of the utility model.
[0017] Wherein, J1, earphone seat, SPK+, audio power amplifier first output end, SPK-, audio power amplifier second output end, MK1, intercom microphone, LS1, intercom loudspeaker, MIC, microphone audio input end, SP DET, microprocessor AD sampling end, UART, simplex communication end, Q1, first triode, Q2, second triode, R1, first resistance, R2, second resistance, R3, third resistance, R4, fourth resistance, R5, fifth resistance, C1, first capacitor, VCC, DC power supply, E1, electrolysis. DETAILED DESCRIPTION
[0018] The intercom comprises the audio circuit as Figure 2 The intercom audio circuit comprises a control module, an earphone seat J1, an audio power amplifier, an electrolysis E1, an intercom microphone MK1, an intercom loudspeaker LS1, a microphone audio, a microphone control circuit, an audio detection circuit, a fourth resistance R4 and a fifth resistance R5.The audio power amplifier and the microphone audio are prior art.The first pin of the earphone seat J1 is connected with one end of the fourth resistance R4, and the other end of the fourth resistance R4 is grounded, that is, the first pin of the earphone seat J1 provides a virtual ground.The third pin of the earphone seat J1 is a communication pin and is connected with a simplex communication end UART, and the specific technology of the simplex communication is prior art.
[0019] The first output end of the BTL audio power amplifier is connected with the positive pole of electrolytic capacitor E1, the negative pole of electrolytic capacitor E1 is connected with the fourth pin of earphone seat J1, and the second output end of the audio power amplifier is connected with the first pin of earphone seat J1. The first pin of intercom loudspeaker LS1 is connected with the connection line between the second output end SPK- of the audio power amplifier and the first pin of earphone seat J1, and the second pin is connected with the fifth pin of earphone seat J1. When the external earphone line is not connected, the fifth pin of earphone seat J1 is connected with the fourth pin through a contact. The first pin of intercom microphone MK1 is connected with the second pin of earphone seat J1, which is used as the microphone audio signal input end MIC. When the external earphone line is connected, the plug of the external earphone line is inserted into the earphone seat, so that the positive pole of the microphone of the external earphone line is connected with the second pin of earphone seat J1, the negative pole of the microphone is connected with the first pin of earphone seat J1, one pin of the loudspeaker of the external earphone line is connected with the first pin of earphone seat J1, and the other pin is connected with the fourth pin of earphone seat J1. The microphone control circuit is connected with the control module, the microphone and the first pin of earphone seat J1 respectively, so as to control the intercom microphone MK1 or the earphone microphone to work. When the external earphone line is connected, the plug of the external earphone line separates the contact between the fourth pin and the fifth pin of earphone seat J1, so that the intercom loudspeaker LS1 stops working. The audio detection is connected with the first output end SPK+ of the audio power amplifier, the fourth pin of earphone seat J1 and the control module respectively, so as to judge whether the audio power amplifier is disconnected with earphone seat J1. The specific structure of the plug of the external earphone line, the microphone and the loudspeaker is the prior art.
[0020] In the embodiment, the control module is specifically a microprocessor.
[0021] The microphone control circuit comprises a first triode Q1 and a second triode Q2. The base of the first triode Q1 is connected with the first I / O port of the microprocessor, the collector is connected with the second pin of the intercom microphone MK1, and the emitter is grounded. The base of the second triode Q2 is connected with the second I / O port of the microprocessor. The collector of the second triode Q2 is connected with the first pin of earphone seat J1, and the emitter of the second triode Q2 is grounded through the fifth resistor R5.
[0022] When the user uses the PTT button on the external earphone line to start the transmission, the microprocessor detects that the transmission is started by the PTT button on the external earphone line (the detection process is prior art), and the first I / O port of the microprocessor is set to low, the base of the first transistor Q1 is low, the collector and emitter of the first transistor Q1 are not conductive, so that the intercom microphone MK1 does not work, and the second I / O port of the microprocessor is set to high, the base of the second transistor Q2 is high, the collector and emitter of the second transistor Q2 are conductive, so that the negative electrode of the external earphone line microphone can be grounded, and the external earphone line microphone works normally. When the user uses the PTT button on the intercom to start the transmission, the microprocessor detects that the transmission is started by the PTT button on the intercom (the detection process is prior art), and the first I / O port of the microprocessor is set to high, the base of the first transistor Q1 is high, the collector and emitter of the first transistor Q1 are conductive, so that the intercom microphone MK1 works normally, and the second I / O port of the microprocessor is set to low, the base of the second transistor Q2 is low, the collector and emitter of the second transistor Q2 are not conductive, so that the negative electrode of the external earphone line microphone cannot be grounded and cannot work. The first transistor Q1 and the second transistor Q2 are both NPN transistors with resistance.
[0023] When the intercom receives, the first output end SPK+ of the audio power amplifier is connected to the fourth pin of the earphone seat J1 through the electrolytic capacitor E1, the fourth pin is connected to the fifth pin of the earphone seat J1 through the contact, and is connected to the second pin of the intercom loudspeaker LS1; the second output end SPK- of the audio power amplifier is divided into two paths, one path is connected to the first pin of the intercom loudspeaker LS1 to drive the intercom loudspeaker LS1, and the other path is connected to the first pin of the earphone seat J1; when the plug of the external earphone line is inserted into the intercom earphone seat J1, the loudspeaker of the external earphone line is connected to the first pin of the earphone seat J1, and the other pin is connected to the fourth pin of the earphone seat J1, and then connected to the first output end SPK+ of the audio power amplifier to drive the loudspeaker of the external earphone line; at the same time, after the plug of the external earphone line is inserted into the earphone seat J1, the plug pushes away the contact point between the fourth pin and the fifth pin of the earphone seat J1, thereby disconnecting the connection between the first output end SPK+ of the audio power amplifier and the intercom loudspeaker LS1, so that the intercom loudspeaker LS1 does not work.
[0024] The audio detection circuit includes a direct current power supply VCC, a first resistor R1, a second resistor R2 and a third resistor R3 connected in series, and a first capacitor C1; one end of the first resistor R1 is connected to the AD sampling end SP DET of the microprocessor, the other end of the first resistor R1 is also connected to the connection line between the first output end SPK+ of the audio power amplifier and the fourth pin of the earphone seat J1; one end of the third resistor R3 is connected to the direct current power supply VCC, the other end of the third resistor R3 is connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is grounded.
[0025] Whether the intercom loudspeaker LS1 or the external earphone line loudspeaker is connected with the earphone seat J1 first foot, the audio power amplifier first output end SPK+ is divided into two ways through electrolytic E1, one way is connected to the microprocessor AD sampling end SPDET through the first resistance R1, when the audio channel is normally connected (the audio power amplifier is not disconnected with the earphone seat J1), the direct current power supply VCC is connected to the earphone seat J1 fourth foot through the third resistance R3 and the second resistance R2, and is connected to the intercom loudspeaker LS1 through the earphone seat J1 fifth foot, and is finally connected to the fourth resistance R4 through the intercom loudspeaker LS1, the fourth resistance R4 is connected with the ground, then the microprocessor AD sampling end SPDET detects the low level, so that the microprocessor judges that the audio channel is normally connected, when the audio channel is disconnected (the audio power amplifier is disconnected with the earphone seat J1), since there is no communication with the fourth resistance R4, then the microprocessor AD sampling end SPDET detects the high level, so as to judge that the audio channel is disconnected.
[0026] The above is only the preferred embodiment of the present application, therefore cannot limit the scope of the present application, that is, the equivalent changes and modifications made according to the patent application scope and the content of the specification should still belong to the scope covered by the present application.
Claims
1. A speakerphone audio circuit, characterized by: The audio circuit comprises a control module, an earphone seat, an audio power amplifier, a speakerphone microphone, a speakerphone loudspeaker, a microphone control circuit and an audio detection circuit, the first output end of the audio power amplifier is connected with the fourth pin of the earphone seat, the second output end of the audio power amplifier is connected with the first pin of the earphone seat, the first pin of the speakerphone loudspeaker is connected with the second output end of the audio power amplifier and the first pin of the earphone seat respectively, the second pin of the speakerphone loudspeaker is connected with the fifth pin of the earphone seat, the first pin of the speakerphone microphone is connected with the second pin of the earphone seat, the first pin of the earphone seat is a virtual ground, when the external earphone line is connected, the positive electrode of the microphone of the external earphone line is connected with the second pin of the earphone seat, the negative electrode of the microphone of the external earphone line is connected with the first pin of the earphone seat, one pin of the loudspeaker of the external earphone line is connected with the first pin of the earphone seat, the other pin of the loudspeaker of the external earphone line is connected with the fourth pin of the earphone seat, the microphone control circuit is connected with the control module, the microphone and the first pin of the earphone seat respectively to control the speakerphone microphone or the earphone microphone to work, when the external earphone line is connected, the external earphone line separates the contact points between the fourth pin and the fifth pin of the earphone seat to stop the speakerphone loudspeaker from working, the audio detection circuit is connected with the first output end of the audio power amplifier, the fourth pin of the earphone seat and the control module respectively to determine whether the audio power amplifier is disconnected with the earphone seat.
2. A radio audio circuit according to claim 1, characterized in that: The control module is a microprocessor.
3. A radio audio circuit according to claim 2, wherein: The microphone control circuit comprises a first triode and a second triode, the base of the first triode is connected with the first I / O port of the microprocessor, the collector of the first triode is connected with the second pin of the speakerphone microphone, the emitter of the first triode is grounded, the base of the second triode is connected with the second I / O port of the microprocessor, the collector of the second triode is connected with the first pin of the earphone seat, the emitter of the second triode is grounded through the fifth resistor.
4. A radio audio circuit according to claim 2 or 3, characterised in that: The audio detection circuit comprises a direct current power supply, a first resistor, a second resistor and a third resistor connected in series, and a first capacitor, one end of the first resistor is connected with the AD sampling end of the microprocessor, the other end of the first resistor is also connected with the first output end of the audio power amplifier and the fourth pin of the earphone seat, one end of the third resistor is connected with the direct current power supply, the other end of the third resistor is connected with one end of the first capacitor, the other end of the first capacitor is grounded.
5. A speakerphone audio circuit according to claim 1 or 2 or 3, characterized in that: It further comprises an electrolyte, the positive electrode of the electrolyte is connected with the second output end of the audio power amplifier, the negative electrode of the electrolyte is connected with the fourth pin of the earphone seat.
6. A speakerphone audio circuit according to claim 1 or 2 or 3, characterized in that: It further comprises a fourth resistor, one end of the fourth resistor is connected with the first pin of the earphone seat, the other end of the fourth resistor is grounded.
7. A speakerphone audio circuit according to claim 1 or 2 or 3, characterized by: The third pin of the earphone seat is a communication pin.
8. A speakerphone, characterized by: The audio circuit comprises the audio circuit according to any one of claims 1-7.