Aging test device for audio power amplifier

Abstract

The utility model relates to the technical field of audio equipment production, and discloses an aging test device for an audio power amplifier, which comprises a box body, and a group of load resistors, a switching power supply, a signal regulator and a control circuit which are arranged in the box body. The surface of the box body is provided with a control panel, the back side of the box body is provided with an interface panel, the interface panel is provided with a signal input interface, a power input interface, a signal output interface, a left channel load interface, a right channel load interface and a power output interface, and the left channel load interface and the right channel load interface are electrically connected with the corresponding load resistors respectively. And the load resistor, the signal regulator, the control circuit, a control key on the control panel and the timing display are electrically connected with the control circuit. The load resistor is arranged on the radiator, and at least one side of the radiator is provided with a cooling fan. According to the aging test device, automatic aging test of the audio power amplifier can be realized, and the stability and the safety of the test process are improved.

Description

Technical Field

[0001] This utility model relates to the field of audio equipment manufacturing technology, specifically to an audio power amplifier aging test device. Background Technology

[0002] Audio power amplifiers, as common audio electronic products, have a wide range of applications and require high stability in their electrical performance. Therefore, audio power amplifiers need to undergo rigorous electrical performance aging tests during the manufacturing process. Depending on the application, the aging test time for audio power amplifiers often exceeds 24 hours, and for high-end products, it can even reach over 72 hours. Due to the long aging time, heat generated by the load resistor gradually accumulates during the aging process, causing changes in the load resistor parameters and affecting the aging effect. To solve the above technical problems, some signal conditioner aging devices use cooling fans to dissipate heat from the load resistor. However, cooling fans alone cannot maintain a stable temperature of the load resistor during the long aging process of audio power amplifiers. Utility Model Content

[0003] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide an audio power amplifier aging test that can improve the stability and safety of the audio power amplifier during the aging process.

[0004] To solve the above problems, the technical solution adopted by this utility model is as follows: An audio power amplifier aging test device includes a housing, a set of load resistors, a switching power supply, a signal conditioner, and a control circuit. The load resistors, the switching power supply, the signal conditioner, and the control circuit are all disposed within the housing. A control panel is disposed on the surface of the housing, and the control panel is provided with control buttons and a timing display. An interface panel is disposed on the back side of the housing, and the interface panel is provided with a signal input interface, a power input interface, a signal output interface, a left channel load interface, a right channel load interface, and a power output interface. The signal input interface is connected to the signal conditioner. The input terminals are electrically connected, the signal output interface is electrically connected to the output terminal of the signal conditioner, the power input interface is electrically connected to the input terminal of the switching power supply, the signal conditioner, and the power output interface, the left channel load interface and the right channel load interface are respectively electrically connected to the corresponding load resistors, the load resistors, the signal conditioner, the control circuit, the control buttons, and the timing display are all electrically connected to the control circuit, the load resistors are mounted on a heat sink, at least one side of the heat sink is provided with a cooling fan, the cooling fan is electrically connected to the control circuit, and the switching power supply is used to power the control circuit.

[0005] Compared with the prior art, the beneficial effects of this utility model are as follows: This aging test device improves the heat dissipation efficiency of the load resistor by placing the load resistor on the heat sink and placing the cooling fan on one side of the heat sink, thereby ensuring that the load resistor maintains a stable temperature during the long-term aging test of the audio power amplifier, and improving the stability and safety of the audio power amplifier during the aging process.

[0006] The aforementioned audio power amplifier aging test device includes a control circuit comprising a power supply circuit, a controller, and a current detection circuit. The load resistor is electrically connected to the controller through the current detection circuit. The input terminal of the power supply circuit is electrically connected to the output terminal of the switching power supply. The power supply circuit is used to supply power to the devices in the control circuit. The control buttons and the timing display are both electrically connected to the controller.

[0007] In the aforementioned audio power amplifier aging test device, a temperature sensor is installed on the heat sink, and the temperature sensor is electrically connected to the control circuit.

[0008] In the aforementioned audio power amplifier aging test device, the control panel is equipped with an air switch, and the power input interface is electrically connected to the power output interface through the air switch.

[0009] The aforementioned audio power amplifier aging test device includes control buttons such as a start button, a pause button, an emergency stop switch, a manual / automatic switching knob, a time setting knob, and a power setting knob.

[0010] The aforementioned audio power amplifier aging test device also includes an indicator light on the control panel, which is electrically connected to the control circuit.

[0011] The aforementioned audio power amplifier aging test device also includes a buzzer inside the enclosure, which is electrically connected to the control circuit.

[0012] The aforementioned audio power amplifier aging test device includes a power supply circuit comprising a first voltage regulator chip and a second voltage regulator chip. The first voltage regulator chip is used to convert the voltage output by the switching power supply into a 5V voltage, and the second voltage regulator chip is used to convert the 5V voltage output by the first voltage regulator chip into a 3.3V voltage.

[0013] The aforementioned audio power amplifier aging test device includes an output DC detection circuit and two load current detection circuits. The input terminal of the output DC detection circuit is electrically connected to both the left channel load interface and the right channel load interface. The input terminal of the load current detection circuit is electrically connected to both ends of the corresponding load resistor.

[0014] In the aforementioned audio power amplifier aging test device, the output terminals of both the DC current detection circuit and the load current detection circuit are electrically connected to the controller via optocouplers.

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the internal structure of the audio power amplifier aging test device according to an embodiment of the present invention;

[0017] Figure 2 This is a schematic block diagram of the control circuit according to an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of the control panel according to an embodiment of the present utility model;

[0019] Figure 4 This is a schematic diagram of the interface panel according to an embodiment of the present utility model;

[0020] Figure 5 This is a schematic diagram of the power supply circuit according to an embodiment of the present utility model;

[0021] Figure 6 This is a schematic diagram of the output DC detection circuit according to an embodiment of the present invention;

[0022] Figure 7 This is a schematic diagram of the load current detection circuit according to an embodiment of the present invention.

[0023] Explanation of icon numbers:

[0024] 100 enclosure, 200 control circuit board, 300 switching power supply, 400 signal conditioner, 500 load resistor, 510 heat sink, 520 cooling fan. Detailed Implementation

[0025] The embodiments of this utility model are described in detail below, with reference to Figure 1 , Figure 3 and Figure 4This utility model provides an audio power amplifier aging test device, including a housing 100, a set of load resistors 500, a switching power supply 300, a signal conditioner 400, and a control circuit. The load resistors 500, switching power supply 300, signal conditioner 400, and control circuit are all housed within the housing 100. A control panel is provided on the surface of the housing 100, featuring control buttons and a timing display. An interface panel is provided on the back of the housing 100, including a signal input interface, a power input interface, a signal output interface, a left channel load interface, a right channel load interface, and a power output interface. The signal input interface is used to connect to a test signal source and is electrically connected to the input terminal of the signal conditioner 400. The signal output interface is connected to the signal input interface of an audio device, inputting the aging test signal, regulated by the signal conditioner 400, to the audio power amplifier under test. The signal output interface is electrically connected to the output terminal of the signal conditioner 400. The power input interface is electrically connected to the input terminal of the switching power supply 300, the signal conditioner 400, and the power output interface. The power input interface is used to connect to mains power to supply power to the aging test device. The left channel load interface and the right channel interface are respectively connected to the left channel output interface and the right channel output interface of the audio power amplifier. The left channel load interface and the right channel load interface are respectively electrically connected to the corresponding load resistor 500. The load resistor 500 is connected between the positive and negative terminals of the left channel load interface or the right channel load interface. The load resistor 500, the signal conditioner 400, the control circuit, the control buttons, and the timing display are all electrically connected to the control circuit. The load resistor 500 is mounted on the heat sink 510, and at least one side of the heat sink 510 has a cooling fan 520, which is electrically connected to the control circuit. The switching power supply 300 supplies power to the control circuit. This aging test device improves the heat dissipation efficiency of the load resistor 500 by placing the load resistor 500 on the heat sink 510 and simultaneously blowing air onto the heat sink 510 and the load resistor 500 by a cooling fan 520 located on one side of the heat sink 510. This allows the temperature of the load resistor 500 to be kept stable during the long aging test of the audio power amplifier, thereby improving the stability and safety of the aging test process.

[0026] Reference Figure 1 In this embodiment, the control circuit is located on the control circuit board 200 inside the housing. (Refer to...) Figure 2The control circuit includes a power supply circuit, a controller, and a current detection circuit. The load resistor 500 is electrically connected to the controller via the current detection circuit, feeding back the load current to the controller, allowing the controller to determine whether the audio power amplifier is operating normally based on the load current magnitude. The input terminal of the power supply circuit is electrically connected to the output terminal of the switching power supply 300, converting the stable voltage output by the switching power supply 300 into the operating voltage required by the devices in the control circuit, thus powering the devices in the control circuit. The control buttons and timer display on the control panel are both electrically connected to the controller. The control buttons can be used to control the start and stop of the aging test process, and the timer within the controller can count the aging test time and display the remaining aging test time on the timer display.

[0027] It is understandable that the heat sink 510 can be a finned heat sink 510 or a metal tube with channels, such as an aluminum square tube. A temperature sensor should preferably be installed on the heat sink 510. The temperature sensor is electrically connected to the controller to provide feedback on the real-time temperature of the load resistor 500, and the speed of the cooling fan 520 is controlled based on the temperature of the load resistor 500, thus achieving closed-loop control of the load resistor 500's temperature. (Refer to...) Figure 1 In this embodiment, the heat sink 510 is made of aluminum square tube, the load resistor 500 is set on the aluminum square tube, and two cooling fans 520 are set at both ends of the aluminum square tube.

[0028] Reference Figure 3In this embodiment, the control buttons on the control panel include an emergency stop switch, a manual / automatic switching knob, a time setting knob, a power setting knob, a start button, and a pause button. The emergency stop switch can be connected to the controller or connected in series after the power input interface to stop the device in an emergency. The manual / automatic switching knob, time setting knob, start button, and pause button are all electrically connected to the controller. The manual / automatic switching knob is used to switch between manual and automatic modes. The time setting knob is used to set the aging time; in this embodiment, the aging time includes four settings: 12 hours, 24 hours, 48 ​​hours, and 72 hours. The power setting knob is used to set the aging power. The power setting knob can be electrically connected to the controller. After the user-selected aging power is fed back to the controller, the controller sends the set power to the signal conditioner 400 via serial communication or other means. The signal conditioner 400 adjusts the source signal of the fixed-frequency signal or sweep-frequency signal to the required power and then sends it to the audio power amplifier being tested through the signal output interface. The power setting knob can also be directly connected to the signal conditioner 400 electrically to directly set the output power of the signal conditioner 400. The start and pause buttons are used to start and pause the aging process, respectively. A relay controlled by the controller can be connected in series between the signal conditioner 400 and the signal output interface. When the user presses the pause button, the controller stops timing and controls the relay to disconnect the signal conditioner 400 from the signal output interface. The controller resumes timing and controls the relay to restore the connection between the signal conditioner 400 and the signal output interface when the user presses the pause button again.

[0029] Reference Figure 3 In this embodiment, to facilitate monitoring of the aging test status, indicator lights are also provided on the control panel. These indicator lights include a normal indicator light, a standby indicator light, and an alarm indicator light, all electrically connected to the controller. When the audio power amplifier is undergoing aging testing, the controller controls the normal indicator light to illuminate. When the current value fed back to the controller by the current detection circuit is abnormal, the controller controls the alarm indicator light to illuminate, alerting the user to the abnormality. When the aging test device is not performing aging work or the aging work is paused, the controller controls the standby indicator light to illuminate. In this embodiment, to more effectively and quickly warn the user when an abnormality occurs, a buzzer is provided inside the housing 100. The buzzer is electrically connected to the controller; when an abnormality occurs during the aging test, the controller simultaneously controls the buzzer to sound an alarm. It is understood that the timing display can be an LCD display or a digital tube, etc. In this embodiment, a four-digit nine-segment digital tube is used. The control circuit also includes a fan drive circuit for driving the cooling fan 520 and a display drive circuit for driving the timing display.

[0030] Reference Figure 5In this embodiment, the power supply circuit includes a first voltage regulator chip U8 and a second voltage regulator chip U9. The input pin 3 of the first voltage regulator chip U8 is electrically connected to the output terminal of the switching power supply 300, and is used to convert the 12V DC power output by the switching power supply 300 into a stable 5V voltage. The input pin 1 of the second voltage regulator chip U9 is electrically connected to the output pin 4 of the first voltage regulator chip U8, and the second voltage regulator chip U9 converts the stable 5V voltage output by the first voltage regulator chip U8 into a stable 3.3V voltage to supply the active devices in the controller and current detection circuit.

[0031] Reference Figure 6 and Figure 7 In this embodiment, the current detection circuit includes an output DC detection circuit and two load current detection circuits. The input terminal of the output DC detection circuit is electrically connected to both the left channel load interface and the right channel load interface. The input terminals of the two load current detection circuits are electrically connected to the two ends of the load resistor 500 of the left channel and right channel, respectively. (Refer to...) Figure 6 In this embodiment, the DC detection circuit includes a first rectifier bridge, operational amplifier U1-A, and operational amplifier U7-A. One end of the input terminal of the first rectifier bridge is electrically connected to the left channel load interface and the right channel load interface, and the other end is grounded. The output terminal of the first rectifier bridge is connected to the two input terminals of operational amplifier U1-A, and the inverting input terminal of operational amplifier U1-A is also connected to its output terminal. The output terminal of operational amplifier U1-A is connected to the inverting input terminal of operational amplifier U7-A, and the inverting input terminal of operational amplifier U7-A is also connected to its output terminal. The non-inverting input terminal of operational amplifier U7-A is grounded, and the output terminal of operational amplifier U7-A is electrically connected to the controller.

[0032] Reference Figure 7 In this embodiment, the load current detection circuit includes a second rectifier bridge, operational amplifier U10-A, and operational amplifier U11-A. The two ends of the input terminal of the second rectifier bridge are connected to the two ends of the load resistor 500, and the output terminal is connected to the two ends of the input terminal of operational amplifier U10-A. The inverting input terminal of operational amplifier U10-A is also connected to its output terminal. The output terminal of operational amplifier U10-A is connected to the inverting input terminal of operational amplifier U11-A, and the inverting input terminal of operational amplifier U11-A is also connected to its output terminal. The non-inverting input terminal of operational amplifier U11-A is grounded through several attenuation resistors R14-R19, and the output terminal of operational amplifier U11-A is electrically connected to the controller. The structures of the two sets of load current detection circuits are similar; the specific structure of the load current detection circuit for the other channel will not be described in detail here. (Refer to...) Figure 6 and Figure 7In this embodiment, to prevent excessive current feedback from the current detection circuit from damaging the controller, the outputs of both the DC detection circuit and the load current detection circuit are electrically connected to the controller via optocouplers. Specifically, the output of operational amplifier U7-A is connected to the controller via optocoupler U37-B, and the output of operational amplifier U11-A is connected to the controller via optocoupler U37-C. It is understood that the controller can be a microcontroller, PLC, or ARM programmable controller. In this embodiment, the controller uses an STM8L151 series microcontroller.

[0033] Reference Figure 3 and Figure 4 It is understood that, in some embodiments, the audio power amplifier aging test device can simultaneously perform aging tests on multiple audio power amplifiers. Accordingly, the control panel needs to be equipped with multiple sets of control buttons, indicator lights, and a timing display; the interface panel should include multiple power output interfaces, signal output interfaces, a left channel load interface, and a right channel load interface; the control circuit should also include multiple sets of current detection circuits; and the required number of load resistors 500Ω need to be installed inside the enclosure 100. In this embodiment, the aging test device can simultaneously perform aging tests on four audio power amplifiers.

[0034] It should be noted that in the description of this utility model, any descriptions of orientation, such as up, down, front, back, left, right, etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and should not be construed as a limitation of this utility model.

[0035] In the description of this utility model, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is mentioned, it is only for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0036] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0037] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. An audio power amplifier aging test device, characterized in that, The system includes a housing (100), a set of load resistors (500), a switching power supply (300), a signal conditioner (400), and a control circuit. The load resistors (500), the switching power supply (300), the signal conditioner (400), and the control circuit are all housed within the housing (100). A control panel is provided on the surface of the housing (100), featuring control buttons and a timing display. An interface panel is located on the back of the housing (100), including a signal input interface, a power input interface, a signal output interface, a left channel load interface, a right channel load interface, and a power output interface. The signal input interface is electrically connected to the input terminal of the signal conditioner (400), and the signal output interface is electrically connected to the input terminal of the signal conditioner (400). The output terminal of the regulator (400) is electrically connected. The power input interface is electrically connected to the input terminal of the switching power supply (300), the signal conditioner (400), and the power output interface. The left channel load interface and the right channel load interface are electrically connected to the corresponding load resistors (500). The load resistors (500), the signal conditioner (400), the control circuit, the control buttons, and the timing display are all electrically connected to the control circuit. The load resistors (500) are mounted on the heat sink (510). At least one side of the heat sink (510) is provided with a cooling fan (520). The cooling fan (520) is electrically connected to the control circuit. The switching power supply (300) is used to supply power to the control circuit.

2. The audio power amplifier aging test apparatus according to claim 1, characterized in that, The control circuit includes a power supply circuit, a controller, and a current detection circuit. The load resistor (500) is electrically connected to the controller through the current detection circuit. The input terminal of the power supply circuit is electrically connected to the output terminal of the switching power supply (300). The power supply circuit is used to supply power to the devices in the control circuit. The control buttons and the timing display are both electrically connected to the controller.

3. The audio power amplifier aging test apparatus according to claim 1, characterized in that, A temperature sensor is provided on the radiator (510), and the temperature sensor is electrically connected to the control circuit.

4. The audio power amplifier aging test apparatus according to claim 1, characterized in that, The control panel is equipped with an air switch, and the power input interface is electrically connected to the power output interface through the air switch.

5. The audio power amplifier aging test apparatus according to claim 1, characterized in that, The control buttons include a start button, a pause button, an emergency stop switch, a manual / automatic switching knob, a time setting knob, and a power setting knob.

6. The audio power amplifier aging test apparatus according to claim 1, characterized in that, The control panel is also equipped with indicator lights, which are electrically connected to the control circuit.

7. The audio power amplifier aging test apparatus according to claim 1, characterized in that, A buzzer is also provided inside the housing (100), and the buzzer is electrically connected to the control circuit.

8. The audio power amplifier aging test apparatus according to claim 2, characterized in that, The power supply circuit includes a first voltage regulator chip and a second voltage regulator chip. The first voltage regulator chip is used to convert the voltage output by the switching power supply (300) into a 5V voltage, and the second voltage regulator chip is used to convert the 5V voltage output by the first voltage regulator chip into a 3.3V voltage.

9. The audio power amplifier aging test apparatus according to claim 2, characterized in that, The current detection circuit includes an output DC detection circuit and two load current detection circuits. The input terminal of the output DC detection circuit is electrically connected to both the left channel load interface and the right channel load interface. The input terminal of the load current detection circuit is electrically connected to both ends of the corresponding load resistor (500).

10. The audio power amplifier aging test apparatus according to claim 9, characterized in that, The outputs of both the DC current detection circuit and the load current detection circuit are electrically connected to the controller via optocouplers.

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