Device for testing sensitivity of microphone of pneumatic sensor

Abstract

The utility model relates to the technical field of sensor sensitivity testing, in particular to a pneumatic sensor microphone sensitivity testing device which comprises an air pump, a switch, an air inlet flow-limiting valve, an air outlet flow-limiting valve, a pressure detection device and a testing circuit. An air inlet and an air outlet of the air pump are communicated with a first channel and a second channel of the switch respectively, one end of the air inlet flow-limiting valve is communicated with the air inlet and the first channel of the switch, and one end of the air outlet flow-limiting valve is communicated with the air outlet and the second channel of the switch; a third channel of the switch is communicated with an output pipeline, and the other end of the output pipeline is communicated with a microphone; the pressure detection device is arranged on the output pipeline and is used for monitoring the air pressure of the output pipeline; the input end of the test circuit is connected with the microphone. By adopting the scheme, the air pressure received by the tested microphone can be accurately adjusted, so that the accuracy of a test result is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sensor sensitivity testing, and particularly relates to a pneumatic sensor microphone sensitivity testing device. Background Art

[0002] In the application and development of modern sensor technology, as an important component, the accuracy of the sensitivity test of the pneumatic sensor microphone is crucial for ensuring the performance of the entire system. Pneumatic sensors are widely used in industrial automation, environmental monitoring, medical equipment and other fields. They can detect changes in gas pressure and convert them into electrical signal outputs. However, despite the growing market demand, the existing pneumatic sensor microphone sensitivity testing devices have obvious deficiencies.

[0003] The testing devices in the prior art usually lack the control of blowing or suction. This means that under different test conditions, the parameters of gas flow cannot be accurately reproduced or adjusted, thus limiting the comprehensive evaluation of the microphone sensitivity. The lack of this control affects the reliability and accuracy of the test results. And the testing devices in the prior art usually cannot accurately monitor and record the change of the capacitance value of the microphone when it is affected by air pressure due to the uncontrollability of air pressure. This will directly affect the accuracy and reliability of the sensitivity test. The inaccuracy of the test results may lead to misoperation or failure of the pneumatic sensor in actual application, thus affecting the stable operation of the entire system.

[0004] In view of the above problems, there is an urgent need to propose a pneumatic sensor microphone sensitivity testing device that can accurately adjust the air pressure received by the microphone to be tested, so as to improve the accuracy of the test results. Summary of the Utility Model

[0005] The utility model provides a pneumatic sensor microphone sensitivity testing device that can accurately adjust the air pressure received by the microphone to be tested, so as to improve the accuracy of the test results.

[0006] In order to achieve the above purpose, the present application provides the following technical solutions:

[0007] A pneumatic sensor microphone sensitivity testing device includes an air pump, a switch, an inlet flow limiting valve, an outlet flow limiting valve, a pressure detection device and a test circuit;

[0008] The inlet and outlet of the air pump are respectively communicated with the first channel and the second channel of the switch. One end of the inlet flow limiting valve is communicated with both the inlet and the first channel of the switch. One end of the outlet flow limiting valve is communicated with both the outlet and the second channel of the switch;

[0009] The third channel of the switch is connected to the output pipeline, and the other end of the output pipeline is connected to the microphone; the pressure detection device is arranged on the output pipeline for monitoring the air pressure of the output pipeline;

[0010] The input end of the test circuit is connected to the microphone.

[0011] Furthermore, it further includes a power supply unit, and the power supply unit is connected to the air pump.

[0012] Furthermore, the power supply unit includes a charging management module, a lithium battery and a boost module;

[0013] The charging management module is connected in parallel with the lithium battery; one end of the boost module is connected to the positive electrode interface of the lithium battery, and the other end serves as the positive electrode of the power supply unit and is connected to the positive terminal of the air pump; the negative electrode interface of the lithium battery serves as the negative electrode of the power supply unit and is connected to the negative terminal of the air pump.

[0014] Furthermore, it further includes a control unit, and the control unit includes a controller and a relay;

[0015] One end of the controller is connected to the power supply unit, and the other end is connected to the relay; the other end of the relay is connected to the air pump;

[0016] The controller controls the opening and closing of the relay.

[0017] Furthermore, the power supply unit includes a charging management module, a lithium battery, a boost module and a buck module;

[0018] The charging management module is connected in parallel with the lithium battery; one end of the boost module is connected to the positive electrode interface of the lithium battery, and the other end is connected to the normally open end of the relay; the positive electrode interface of the lithium battery is also connected to one end of the buck module, and the other end of the buck module is connected to the positive power supply end of the controller; the positive power supply end of the controller is also connected to the positive pole of the DC power supply of the relay; the signal output end of the controller is connected to the control signal input end of the relay, and the grounding end is connected to the negative pole of the DC power supply of the relay; the common end of the relay is connected to the positive terminal of the air pump, and the negative electrode interface of the lithium battery is connected to the negative terminal of the air pump.

[0019] Furthermore, an adjustment branch is provided between the output pipeline and the microphone. One end of the adjustment branch is connected to the output port of the output pipeline, and the other end is connected to the microphone; a regulating valve is provided on the adjustment branch.

[0020] Furthermore, the adjustment branch includes an intake adjustment branch and an exhaust adjustment branch; the regulating valve includes an intake regulating valve and an exhaust regulating valve;

[0021] The intake regulating valve is arranged on the intake regulating branch, and the outlet regulating valve is arranged on the outlet regulating branch.

[0022] Further, the pressure detection device is one of a pressure gauge, a pressure tester, and a pressure sensor.

[0023] Further, the output pipeline is a flexible hose.

[0024] The principle and advantages of the present utility model are as follows:

[0025] 1. In this solution, the air pump provides gas into the output pipeline to provide a test environment for the subsequent sensitivity test of the microphone head. Then, by connecting the intake port and the outlet port of the air pump to the first channel and the second channel of the switch respectively, the third channel of the switch is connected to the output pipeline, and one end of the intake port flow-limiting valve is connected to both the intake port and the first channel of the switch, and one end of the outlet port flow-limiting valve is connected to both the outlet port and the second channel of the switch, the effect of flexibly adjusting the air pressure in the output pipeline is achieved, and the air pressure in the output pipeline can be displayed in real time through the pressure detection device.

[0026] 2. The power supply unit includes a charging management module, a lithium battery, a boost module, and a buck module, so that appropriate voltages can be provided for the relay and the controller through the boost module and the buck module respectively.

[0027] 3. By providing an intake regulating branch and an outlet regulating branch between the output port of the output pipeline and the microphone head, and installing an intake regulating valve and an outlet regulating valve respectively, the effect of ensuring that the gas flows from the air pump into the pipeline system and preventing reverse flow is achieved.

[0028] In summary, by adopting this solution, the air pressure can be accurately regulated, thereby improving the accuracy of the test results, and by providing flexible voltage regulation, the versatility and practicality of the test device are improved. Description of the Drawings

[0029] Figure 1 It is a schematic connection structure diagram of the overall structure in Embodiment 1 of a pneumatic sensor microphone head sensitivity test device of the present utility model.

[0030] Figure 2 It is a schematic connection structure diagram of the overall structure in Embodiment 2 of a pneumatic sensor microphone head sensitivity test device of the present utility model.

[0031] Figure 3 It is a schematic installation structure diagram of a flow-limiting valve in an embodiment of a pneumatic sensor microphone head sensitivity test device of the present utility model.

[0032] Figure 4 It is a circuit diagram of a test circuit in an embodiment of a pneumatic sensor microphone head sensitivity test device of the present utility model. Detailed implementation manners

[0033] The following is a further detailed description through specific implementation manners:

[0034] Example 1:

[0035] Example 1 is as shown in the attached Figure 1 figure:

[0036] A pneumatic sensor microphone sensitivity testing device is used to test the sensitivity of a microphone. In this example, the sensitivity of a capacitive electret microphone is tested. As shown Figure 1 in the figure, the sensitivity testing device includes an air pump, a switch, an inlet flow-limiting valve, an outlet flow-limiting valve, a pressure detection device, a test circuit, and a power supply unit. In this example, the model of the air pump is KLC2-A; the switch uses a quick-release ball valve; the pressure detection device is one of a pressure gauge, a pressure tester, and a pressure sensor. In this example, a pressure gauge of model EM2000A is specifically used.

[0037] The power supply unit is connected to the air pump to supply power to the air pump. Specifically, the power supply unit includes a charging management module, a lithium battery, and a boost module. In this example, the lithium battery is a rechargeable lithium battery, and the charging management module is connected in parallel with the lithium battery to charge the lithium battery. One end of the boost module is connected to the positive interface VBAT of the lithium battery, and the other end is used as the positive pole of the power supply unit and is connected to the positive terminal of the air pump. The boost module is used to boost the discharge voltage of the lithium battery and transmit the boosted voltage to the air pump. The negative interface GND of the lithium battery is used as the negative pole of the power supply unit and is connected to the negative terminal of the air pump, thereby forming a loop to complete the power supply of the power supply unit to the air pump. In this example, the model of the charging management module is AX1101, the model of the lithium battery is 18650, and the model of the boost module is PW5100.

[0038] As shown Figure 3 in the figure, the air pump includes an inlet and an outlet. Whether the inlet and the outlet are connected to the output channel is controlled by a switch. When it is necessary to perform an inhalation test on the microphone, the switch is used to switch the output pipeline to the inlet. When the test time is over, the connection between the inlet and the output pipeline is closed; when it is necessary to perform a blowing test on the microphone, the switch is used to switch the output pipeline to the outlet. When the test time is over, the connection between the outlet and the output pipeline is closed. The method of the switch switching the output pipeline to connect to the inlet or the outlet of the air pump can achieve the conversion and adjustment of the inhalation or blowing mode of the device and control the inhalation or blowing time.

[0039] Specifically, the air inlet and the air outlet of the air pump are respectively communicated with the first channel and the second channel of the switch; one end of the air inlet flow limiting valve is communicated with both the air inlet and the first channel of the switch, and the other end is communicated with the external environment; one end of the air outlet flow limiting valve is communicated with both the air outlet and the second channel of the switch, and the other end is communicated with the external environment; the third channel of the switch is communicated with the output pipeline. In this embodiment, the switch adopts a quick-connect ball valve, that is, the air inlet is connected to the first channel of the quick-connect ball valve, the air outlet is connected to the second channel of the quick-connect ball valve, and the output pipeline is connected to the third channel of the quick-connect ball valve. When it is necessary to connect the air inlet to the output pipeline, the air valve handle is manually rotated. When the handle faces the first channel, the first channel communicates with the third channel. At the same time, it is necessary to open the air outlet flow limiting valve and close the air inlet flow limiting valve. The gas flows from the output pipeline through the third channel and the first channel to the air inlet in sequence, and the gas at the air outlet of the air pump flows out through the air outlet flow limiting valve; when it is necessary to connect the air outlet to the output pipeline, the air valve handle is manually rotated. When the handle faces the second channel, the second channel communicates with the third channel. At the same time, it is necessary to open the air inlet flow limiting valve and close the air outlet flow limiting valve. The gas flows from the air outlet of the air pump through the second channel and the third channel to the output pipeline in sequence, and the gas flows into the air pump through the air inlet flow limiting valve.

[0040] The other end of the output pipeline is communicated with the microphone to provide a test environment. As Figure 1 shown, an adjustment branch is provided between the output pipeline and the microphone. One end of the adjustment branch is communicated with the output port of the output pipeline, and the other end is communicated with the microphone; a regulating valve is provided on the adjustment branch. Specifically, the adjustment branch includes an air inlet adjustment branch and an air outlet adjustment branch; the regulating valve includes an air inlet regulating valve and an air outlet regulating valve; as Figure 1 shown, the air inlet regulating valve is arranged on the air inlet adjustment branch, and the air outlet regulating valve is arranged on the air outlet adjustment branch.

[0041] In this embodiment, the output pipeline is a flexible hose. During the suction test, the gas flow rate is controlled by adjusting the air inlet regulating valve, so as to control the gas pressure in the flexible hose; during the blowing test, the gas flow rate is controlled by adjusting the air outlet regulating valve, so as to control the gas pressure in the flexible hose.

[0042] As Figure 1As shown, a pressure detection device is connected inside the output pipeline, which is used to monitor the air pressure in the output pipeline and display the specific pressure value of the gas in the output channel in real time. The sensitivity tester can understand the air pressure in the output pipeline by checking the value displayed by the pressure detection device, and flexibly control the air pressure value in the output pipeline by adjusting the switch. The pressure on the microphone under test is positively correlated with the air pressure of inhalation or exhalation received. When the microphone is affected by air pressure, the capacitance value of the microphone will change. Therefore, as the gas flow rate increases, the air pressure in the hose increases, and the pressure on the microphone increases. As the pressure increases, the capacitance value of the microphone changes. The microphone is externally connected to a test circuit, and the test circuit can detect the change of the capacitance value of the microphone. When the capacitance value changes beyond a preset degree, the output state of the test circuit will change. The minimum pressure value that causes the output state of the test circuit to change is the obtained microphone sensitivity value, where the pressure value is the value displayed by the pressure gauge.

[0043] Specifically, the input end of the test circuit is connected to the microphone. The test circuit is a test chip, and the internal circuit diagram of the chip is as Figure 4 shown. The test circuit includes a first clock generation circuit OSC1, a second clock generation circuit OSC2, a pneumatic detection and judgment circuit, and a drive module driver. The microphone is connected to the input end of the test chip, and the other end of the input end of the test chip is connected to the second clock generation circuit OSC2. The first clock generation circuit OSC1 and the second clock generation circuit OSC2 are both connected to the pneumatic detection and judgment circuit. The pneumatic detection and judgment circuit is also connected to the drive module driver, and the other end of the drive module is connected to the output end of the test chip. The working principle of the test chip is as follows: The frequency of the first clock generation circuit OSC1 is fixed, and the frequency of the second clock generation circuit OSC2 is negatively correlated with the detected capacitance of the microphone. After the test chip is powered on, the pneumatic detection and judgment circuit continuously detects the change in the ratio of the frequencies of the first clock generation circuit OSC1 and the second clock generation circuit OSC2. When the ratio of the frequencies of the first clock generation circuit OSC1 and the second clock generation circuit OSC2 changes beyond a preset ratio, the drive module driver starts to work and outputs through the output end OUT of the test chip.

[0044] Embodiment 2:

[0045] Embodiment 2 is basically as shown in the appendix Figure 2 shown:

[0046] The basic principle of Embodiment 2 is the same as that of Embodiment 1, and the difference is that in Embodiment 2, the power supply unit includes a charging management module, a lithium battery, a boost module, and a buck module, and the sensitivity test device further includes a control unit. In this embodiment, the model of the buck module is PW2057.

[0047] The control unit includes a relay and a controller for controlling the opening and closing of the relay; one end of the controller is connected to the power supply unit, and the other end is connected to the relay; the other end of the relay is connected to the air pump, and thus, power is supplied to the air pump through the relay. In this embodiment, the relay uses a 1-channel opto-isolated relay, and the controller uses an MCU with the model SMT32.

[0048] Specifically, as Figure 2 shown, the charging management module is connected in parallel with the lithium battery; one end of the boost module is connected to the positive interface VBAT of the lithium battery, and the other end is connected to the normally open end of the relay, which is used to boost the discharge voltage of the lithium battery. The positive interface VABT of the lithium battery is also connected to one end of the buck module, and the other end of the buck module is connected to the positive power supply terminal VCC of the controller; the positive power supply terminal VCC of the controller is also connected to the positive pole DC+ of the DC power supply of the relay; the signal output terminal IO of the controller is connected to the control signal input terminal IN of the relay, and the ground terminal GND is connected to the negative pole DC- of the DC power supply of the relay; the common terminal of the relay is connected to the positive terminal of the air pump, and the negative interface of the lithium battery is connected to the negative terminal of the air pump to form a loop, completing the power supply of the power supply unit to the air pump device.

[0049] By programming the controller, the control of the relay can be achieved. When the signal output terminal IO of the controller outputs a high-level signal, the control signal input terminal IN of the relay receives the high-level signal. At this time, the normally open end and the common end of the relay are short-circuited, that is, the positive pole of the air pump motor is connected to the VBAT port of the battery through the boost module, realizing the power supply to the air pump. When the signal output terminal IO of the controller outputs a low-level signal, the control signal input terminal IN of the relay receives the low-level signal. At this time, the normally open end and the common end of the relay are disconnected, that is, the positive pole of the air pump motor is not connected to the VBAT port of the lithium battery, and the air pump is not powered. In summary, adopting this solution, the controller can be programmed to control the level of the electrical signal output by its signal output terminal IO, thereby directionally controlling whether the air pump is powered, achieving precise control of the inhalation or exhalation time and frequency.

[0050] The above are only embodiments of the present utility model. Specific structures and common knowledge such as characteristics that are well-known in the art are not described in detail herein. Those of ordinary skill in the art know all the general technical knowledge in the technical field to which the utility model pertains before the filing date or the priority date, can acquire all the prior arts in this field, and have the ability to apply the conventional experimental means before this date. Those of ordinary skill in the art can, under the inspiration given by this application, combine their own abilities to improve and implement this solution. Some typical well-known structures or well-known methods should not become obstacles for those of ordinary skill in the art to implement this application. It should be noted that for those skilled in the art, without departing from the structure of the present utility model, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present utility model, and these will not affect the implementation effect of the present utility model and the practicality of the patent. The protection scope required by this application shall be subject to the content of its claims, and the specific implementation manners and the like recorded in the specification can be used to interpret the content of the claims.

Claims

1. A pneumatic sensor microphone sensitivity testing device, characterized in that: It includes an air pump, a switch, an inlet flow-limiting valve, an outlet flow-limiting valve, a pressure detection device and a test circuit; The inlet and outlet of the air pump are respectively connected to the first channel and the second channel of the switch. One end of the inlet flow-limiting valve is connected to both the inlet and the first channel of the switch. One end of the outlet flow-limiting valve is connected to both the outlet and the second channel of the switch; The third channel of the switch is connected to the output pipeline, and the other end of the output pipeline is connected to the microphone. The pressure detection device is arranged on the output pipeline for monitoring the air pressure of the output pipeline; The input end of the test circuit is connected to the microphone.

2. The pneumatic sensor microphone sensitivity testing device according to claim 1, wherein: It further includes a power supply unit, and the power supply unit is connected to the air pump.

3. The pneumatic sensor microphone sensitivity testing device according to claim 2, wherein: The power supply unit includes a charging management module, a lithium battery and a boost module; The charging management module is connected in parallel with the lithium battery. One end of the boost module is connected to the positive interface of the lithium battery, and the other end is used as the positive pole of the power supply unit and is connected to the positive terminal of the air pump. The negative interface of the lithium battery is used as the negative pole of the power supply unit and is connected to the negative terminal of the air pump.

4. The pneumatic sensor microphone sensitivity testing device according to claim 2, characterized in that: It further includes a control unit, and the control unit includes a controller and a relay; One end of the controller is connected to the power supply unit, and the other end is connected to the relay. The other end of the relay is connected to the air pump; The controller controls the opening and closing of the relay.

5. The pneumatic sensor microphone sensitivity testing device according to claim 4, characterized in that: The power supply unit includes a charging management module, a lithium battery, a boost module and a buck module; The charging management module is connected in parallel with the lithium battery. One end of the boost module is connected to the positive interface of the lithium battery, and the other end is connected to the normally open end of the relay. The positive interface of the lithium battery is also connected to one end of the buck module, and the other end of the buck module is connected to the positive power supply end of the controller. The positive power supply end of the controller is also connected to the positive pole of the DC power supply of the relay. The signal output end of the controller is connected to the control signal input end of the relay, and the grounding end is connected to the negative pole of the DC power supply of the relay. The common end of the relay is connected to the positive terminal of the air pump, and the negative interface of the lithium battery is connected to the negative terminal of the air pump.

6. The pneumatic sensor microphone sensitivity testing device according to claim 1, wherein: An adjustment branch is provided between the output pipeline and the microphone. One end of the adjustment branch is connected to the output port of the output pipeline, and the other end is connected to the microphone. A regulating valve is provided on the adjustment branch.

7. The pneumatic sensor microphone sensitivity testing device according to claim 6, characterized in that: The adjustment branch includes an inlet adjustment branch and an outlet adjustment branch; the regulating valve includes an inlet adjustment valve and an outlet adjustment valve; The inlet adjustment valve is arranged on the inlet adjustment branch, and the outlet adjustment valve is arranged on the outlet adjustment branch.

8. The pneumatic sensor microphone sensitivity testing device according to claim 1, wherein: The pressure detection device is one of a pressure gauge, a pressure tester and a pressure sensor.

9. The pneumatic sensor microphone sensitivity testing device according to claim 1, characterized in that: The output pipeline is a flexible pipe.

Images