US-12627923-B2 - Vehicle-mounted sound system and open-circuit detection method for loudspeaker thereof

US12627923B2US 12627923 B2US12627923 B2US 12627923B2US-12627923-B2

Abstract

Discloses are a vehicle-mounted sound system, an open-circuit detection circuit and an open-circuit detection method for a loudspeaker thereof. The vehicle-mounted sound system includes an open-circuit detection circuit including a switching circuit, the switching circuit is connected between an output port of a control module of a power amplifier and a first connecting port so as to be controlled by a control signal from an output port to conduct or cut off the output port and the first connecting port. The second connecting port is electrically connected to a node for accessing a voltage together with an input port of the control module. The control module is configured for enabling the open-circuit detection circuit though the output port to determine whether the loudspeaker is in an open-circuit state according to a signal received by the input port.

Inventors

Hongbing DING
Yurong Wu

Assignees

SUZHOU SONAVOX ELECTRONICS CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20211220
Priority Date: 20210322

Claims (12)

1 . A vehicle-mounted sound system, comprising: a power amplifier configured to drive a vehicle-mounted loudspeaker electrically connected thereto; a control module configured to control the power amplifier, and having an output port and an input port; and an open-circuit detection circuit having a first connecting port and a second connecting port, one of the first connecting port and the second connecting port being electrically connected to a positive lead of the vehicle-mounted loudspeaker and the other one of the first connecting port and the second connecting port being electrically connected to a negative lead of the vehicle-mounted loudspeaker; wherein: the open-circuit detection circuit comprises a single switching circuit, the single switching circuit is connected between the output port of the control module and the first connecting port so as to be controlled by a control signal from the output port to conduct or cut off the output port and the first connecting port; the input port of the control module and the second connecting port are electrically connected to a node for accessing a voltage; the control module is configured to enable the open-circuit detection circuit through the output port to determine whether the vehicle-mounted loudspeaker is in an open-circuit state according to a signal received by the input port; the single switching circuit comprises a single triode, a base of the single triode is electrically connected to the output port, a collector of the single triode is electrically connected to the first connecting port, and an emitter of the single triode is grounded; and the open-circuit detection circuit further comprises a diode configured to prevent a voltage of the power amplifier from striking back to the control module, and the diode is electrically connected between the second connecting port and the input port.
2 . The vehicle-mounted sound system according to claim 1 , wherein the single switching circuit further comprises a first resistor and a second resistor, the first resistor is electrically connected between the output port and a gate of the single triode, one end of the second resistor is electrically connected to a middle point between the first resistor and the gate of the single triode, and the other end of the second resistor is electrically connected to the collector of the single triode.
3 . The vehicle-mounted sound system according to claim 1 , wherein the open-circuit detection circuit further comprises a third resistor connected between the single switching circuit and the first connecting port.
4 . The vehicle-mounted sound system according to claim 1 , wherein the node is electrically connected to a power supply terminal to access the voltage.
5 . The vehicle-mounted sound system according to claim 4 , wherein the open-circuit detection circuit further comprises a fourth resistor, and the fourth resistor is electrically connected between the power supply terminal and the node.
6 . The vehicle-mounted sound system according to claim 1 , wherein the open-circuit detection circuit further comprises a capacitor, an end of the capacitor is electrically connected to a middle point between the second connecting port and the input port, and the other end of the capacitor is grounded.
7 . The vehicle-mounted sound system according to claim 1 , wherein the power amplifier is a BTL power amplifier; and/or, the control module is a power amplifier chip, and the output port and the input port are IO ports of the power amplifier chip, respectively.
8 . The vehicle-mounted sound system according to claim 1 , wherein the vehicle-mounted loudspeaker is a loudspeaker with an impedance range of 2-8 Ω.
9 . An open-circuit detection method for a loudspeaker of the vehicle-mounted sound system according to claim 1 , comprising a step of open-circuit detection, the step of open-circuit detection comprising: enabling the output port of the control module to switch the single switching circuit on; determining, when the signal received by the input port of the control module is a high-level signal, that the vehicle-mounted loudspeaker is in the open-circuit state; and determining, when the signal received by the input port of the control module is a low-level signal, that the vehicle-mounted loudspeaker is in a non-open-circuit state.
10 . The open-circuit detection method for the loudspeaker according to claim 9 , further comprising enabling the power amplifier in an off state and enabling the output port and the input port in a low-level state when initially powered on.
11 . An open-circuit detection circuit of a vehicle-mounted sound system, comprising a first connecting port and a second connecting port, wherein: one of the first connecting port and the second connecting port is electrically connected to a positive lead of a vehicle-mounted loudspeaker and the other one of the first connecting port and the second connecting port is electrically connected to a negative lead of the vehicle-mounted loudspeaker; the open-circuit detection circuit comprises a single switching circuit, the single switching circuit is connected between an output port of a control module of a power amplifier and the first connecting port so as to be controlled by a control signal from the output port to conduct or cut off the output port and the first connecting port; the second connecting port is electrically connected to a node for accessing a voltage together with an input port of the control module; the single switching circuit comprises a single triode, a base of the single triode is electrically connected to the output port, a collector of the single triode is electrically connected to the first connecting port, and an emitter of the single triode is grounded; and the open-circuit detection circuit further comprises a diode configured to prevent a voltage of the power amplifier from striking back to the control module, and the diode is electrically connected between the second connecting port and the input port.
12 . The open-circuit detection circuit according to claim 11 , wherein: the single switching circuit comprises a first resistor and a second resistor, the first resistor is electrically connected between the output port and a gate of the single triode, one end of the second resistor is electrically connected to a middle point between the first resistor and the gate of the single triode, and the other end of the second resistor is electrically connected to the collector of the single triode; the open-circuit detection circuit further comprises a third resistor connected between the single switching circuit and the first connecting port; the node is electrically connected to a power supply terminal to access the voltage; and the open-circuit detection circuit further comprises a fourth resistor, and the fourth resistor is electrically connected between the power supply terminal and the node.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the U.S. National Phase under 35. U.S.C. § 371 of International Application PCT/CN2021/139480, filed Dec. 20, 2021, which claims priority from Chinese Patent Application No. CN202110301372.8 filed on Mar. 22, 2021. The disclosures of the above-described applications are hereby incorporated by reference in their entirety. FIELD OF TECHNOLOGY The present disclosure belongs to the field of audio, and in particular, relates to a vehicle-mounted sound system and an open-circuit detection method for a loudspeaker thereof. BACKGROUND Currently, power amplifier chips have their own function of diagnosing open-circuit or short-circuit of loudspeakers and the function of protecting when the loudspeakers is open-circuited or short-circuited, which are expensive and costly. However, in the vehicle-mounted sound systems, considering cost reasons, the vehicle-mounted power amplifier chips used in the vehicle-mounted sound systems do not have the function of diagnosing open-circuit or short-circuit of loudspeakers. When selecting this type of power amplifier chips, if it is needed to detect if a loudspeaker is mounted in the vehicle or if the loudspeaker is correctly connected, then a circuit or system for detecting open-circuit of loudspeaker must be added to the mass-produced product to complete this function, so as to determine whether it is in a loudspeaker open-circuit state, which refers to the absence of a loudspeaker or the fact that a loudspeaker is mounted but not properly connected. SUMMARY An aspect of the present disclosure relates to a vehicle-mounted sound system, which can achieve the open-circuit detection of the loudspeaker of the vehicle-mounted sound system at a relatively low cost. Another aspect of the present invention relates to an open-circuit detection method for a loudspeaker of a vehicle-mounted sound system, which can achieve the open-circuit detection of the loudspeaker of the vehicle-mounted sound system at a relatively low cost. A first aspect of the present disclosure provides a vehicle-mounted sound system comprises: a power amplifier for driving a vehicle-mounted loudspeaker electrically connected to the power amplifier; anda control module for controlling the power amplifier, and having an output port and an input port;the vehicle-mounted sound system further comprises:an open-circuit detection circuit having a first connecting port and a second connecting port, one of the first connecting port and the second connecting port being electrically connected to a positive lead of the vehicle-mounted loudspeaker and the other one being electrically connected to a negative lead of the vehicle-mounted loudspeaker;wherein, the open-circuit detection circuit comprises a switching circuit, and the switching circuit is connected between the output port of the control module and the first connecting port so as to be controlled by a control signal from the output port to conduct or cut off the output port and the first connecting port;the input port of the control module and the second connecting port are respectively electrically connected to a node for accessing a voltage;the control module is configured for enabling the open-circuit detection circuit though the output port to determine whether the loudspeaker is in an open-circuit state according to a signal received by the input port. Herein, the “loudspeaker in an open-circuit state” refers to the absence of a vehicle-mounted loudspeaker or the fact that a vehicle-mounted loudspeaker is mounted but not properly connected, such as not properly connected to the power amplifier. In an embodiment, the switching circuit comprises a triode, the base of the triode is electrically connected to the output port, the collector of the triode is electrically connected to the first connecting port, and the emitter of the triode is grounded. Optionally, the triode is an NPN type triode. In an embodiment, the switching circuit further comprises a first resistor and a second resistor, the first resistor is electrically connected between the output port and the gate of the triode, one end of the second resistor is electrically connected to a middle point between the first resistor and the gate of the triode, and the other end of the second resistor is electrically connected to the collector of the triode. In an embodiment, the first resistor, the second resistor and the triode together form the switching circuit. In an embodiment, the open-circuit detection circuit further comprises a third resistor connected between the switching circuit and the first connecting port. The third resistor is used for current limiting. In an embodiment, the node is electrically connected to a power supply terminal to access a voltage. In an embodiment, the open-circuit detection circuit further comprises a fourth resistor for pulling up the level transmitted to an IO port, and the fourth resistor is electrically connected