Motor current detection circuit and insect situation forecasting instrument

Abstract

The utility model provides a motor current detection circuit and an insect situation forecasting instrument. The current detection circuit comprises at least two driving circuits; each relay is connected with the corresponding driving circuit, one output end of each relay is connected with a target motor, and the other output end of each relay is provided with a grounding point for current detection; the grounding point is grounded through the resistor R14, and current output by the grounding point flows through the resistor R14 to generate detection voltage; the output end of the in-phase amplifier is connected with a specified detection port; and the detection voltage is input to the in-phase amplifier for amplification and is output to the specified detection port through the output end of the in-phase amplifier. According to the insect situation measuring and reporting instrument, the current detection circuit detects the driving current for driving the sweeping motor, the working state of the sweeping motor is controlled according to the current, and the sweeping motor is prevented from being damaged.

Description

TECHNICAL FIELD

[0001] The utility model relates to insect situation measuring and reporting instrument technical field especially relates to a motor current detection circuit and insect situation measuring and reporting instrument. BACKGROUND

[0002] In the operation process of the insect situation measuring and reporting instrument, the insect tray needs to be cleaned by the cleaning sliding table after the photographing is completed, and the cleaning sliding table becomes not smooth with the passage of time due to the difference in the use environment, such as humidity and dust size. The unsmooth cleaning sliding table will increase the load of the cleaning motor, resulting in an increase in the driving current of the cleaning motor. However, the current insect situation measuring and reporting instrument cannot detect the driving current of the cleaning motor. In addition, the cleaning sliding table will not stop until it reaches the limit switch, and the long-time operation of the cleaning sliding table under the condition of excessive current will cause the circuit board line to be burned out, and finally a professional person has to be sent to the scene for maintenance. SUMMARY

[0003] The utility model embodiment provides a motor current detection circuit and insect situation measuring and reporting instrument to solve the problems in the related art, and the technical scheme is as follows:

[0004] In a first aspect, the utility model embodiment provides a motor current detection circuit, which comprises:

[0005] At least two driving circuits;

[0006] At least two relays, each relay is connected with its corresponding driving circuit, and one output end of each relay is connected with a target motor, and the other output end is provided with a grounding point for current detection;

[0007] A resistor R14, the grounding point is grounded through the resistor R14, and the current output by the grounding point flows through the resistor R14 to generate a detection voltage;

[0008] A same-phase amplifier, the output end of the same-phase amplifier is connected with a specified detection port; the detection voltage is input to the same-phase amplifier for amplification and output to the specified detection port through the output end of the same-phase amplifier.

[0009] In an embodiment, the driving circuit comprises a resistor R514, a resistor R510, a resistor R515 and a triode Q504, the base of the triode Q504 is connected with the driving circuit through the resistor R510, the resistor R514 and the resistor R515 are connected between the base and the emitter of the triode Q504, and the emitter of the triode Q504 is grounded; the collector of the triode Q504 is connected with the relay.

[0010] In an embodiment, the relay includes a first relay connected to a positive pole of the target motor and a second relay connected to a negative pole of the target motor, and the first relay and the second relay are configured to control a working state of the target motor, and the working state includes a pause motion, a forward motion and a reverse motion.

[0011] In an embodiment, the motor current detection circuit further includes:

[0012] A gain circuit composed of the resistor R4 and the resistor R5 is connected to the inverting input terminal of the non-inverting amplifier.

[0013] In an embodiment, the motor current detection circuit further includes:

[0014] The controller unit is connected to the designated detection port and configured to receive the amplified voltage amplified by the non-inverting amplifier.

[0015] In an embodiment, each of the drive circuits has a corresponding signal source port connected to the controller unit.

[0016] In an embodiment, the current detection circuit further includes a TVS diode D8 and a TVS diode D9 connected in parallel between the grounding point and the non-inverting input terminal of the non-inverting amplifier.

[0017] In a second aspect, the utility model provides a kind of pest situation measuring instrument, including the motor current detection circuit as described above.

[0018] The above technical solution has at least the following advantages or beneficial effects:

[0019] The utility model is driven by the drive circuit to drive the relay to run, and the working state of the target motor is controlled by the relay.The current detection circuit detects the current output by the grounding point of the relay, and outputs the amplified current to the designated detection port through the non-inverting amplifier.The pest situation measuring instrument identifies the driving current of the driving cleaning motor through the designated detection port, controls the working state of the cleaning motor according to the current size, and controls the cleaning motor to pause working when the current is too large to avoid damaging the cleaning motor.

[0020] The above summary is only for the purpose of the description and is not intended to limit in any way. In addition to the above-described exemplary aspects, embodiments and features, further aspects, embodiments and features of the utility model will be readily apparent to those skilled in the art by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0021] In the drawings, like reference numerals are used to designate like parts throughout the various drawings. The drawings are not necessarily to scale. It should be understood that the drawings only depict some embodiments consistent with the disclosure and should not be considered limiting of the scope of the disclosure.

[0022] Figure 1 A circuit connection schematic diagram of the first driving circuit and the first relay of the present application;

[0023] Figure 2 A circuit connection schematic diagram of the second driving circuit and the second relay of the present application;

[0024] Figure 3 An interface schematic diagram of the target motor of the present application;

[0025] Figure 4 A circuit schematic diagram connected to the grounding point of the present application. DETAILED DESCRIPTION

[0026] In the following, only some exemplary embodiments are described briefly. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and the description are considered to be exemplary in nature rather than limiting.

[0027] Embodiment One

[0028] The motor current detection circuit provided by the embodiments of the present application can detect the driving current of the target motor. The motor current detection circuit specifically comprises:

[0029] at least two driving circuits;

[0030] at least two relays, each of which is connected to its corresponding driving circuit, and one output end of each of the relays is connected to the target motor, and the other output end is provided with a grounding point for current detection;

[0031] a resistor R14, the grounding point is grounded through the resistor R14, and the current output by the grounding point flows through the resistor R14 to generate a detection voltage;

[0032] a same-phase amplifier, the output end of the same-phase amplifier is connected with a specified detection port; the detection voltage is input to the same-phase amplifier for amplification and is output to the specified detection port through the output end of the same-phase amplifier.

[0033] In the present embodiment, the motor current detection circuit comprises two driving circuits, which are named as the first driving circuit and the second driving circuit respectively; and two relays, which are named as the first relay K504 and the second relay K507 respectively. Specifically:

[0034] As shown in Figure 1 , the first drive circuit has a signal source port QS1, which is used to input a control signal. According to the control signal, the drive circuit can switch the working state of the target motor. The first drive circuit includes a resistor R514, a resistor R510, a resistor R515, and a transistor Q504. The transistor Q504 is an NPN transistor. The base of the transistor Q504 is connected to the signal source port through the resistor R510. The resistor R514 and the resistor R515 are connected between the base of the transistor Q504 and the emitter of the transistor Q504. The emitter of the transistor Q504 is grounded. The collector of the transistor Q504 is connected to the first relay K504 through a diode D504. One output terminal QS1_OUT of the first relay K504 is connected to the positive electrode of the target motor. The other output terminal of the first relay K504 is a ground terminal GND_Current_detection, which is used for current detection.

[0035] When the signal source port QS1 inputs a low level in this embodiment, the transistor Q504 is not conductive, resulting in no current passing through the coil of the first relay K504. The first relay K504 is not closed, and QS1_OUT is connected to 24V_IN at this time.

[0036] When the signal source port QS1 inputs a high level, the voltage between the resistor R510, the resistor R515, and the base of the transistor Q504 is greater than 0.7V. At this time, the transistor Q504 is in a saturated conduction state. When the transistor Q504 is in a saturated conduction state, the coil voltage of the first relay K504 is 24V. The first relay K504 is closed to disconnect QS1_OUT from 24V_IN. At this time, the output of the first relay K504 is connected to the ground terminal GND_Current_detection.

[0037] Similarly, the working principle of the second relay K507 is the same as that of the first relay K504. As shown in Figure 2 , the second relay K507 also has a signal source port QS2. The signal source port QS2 is connected to the transistor Q507 through the resistor R523, the resistor R526, and the resistor R527. The transistor Q507 is connected to the second relay K507 through the diode D507. One output terminal QS2_OUT of the second relay K507 is connected to the negative electrode of the target motor through a fuse holder. The other output terminal of the second relay K507 is a ground terminal GND_Current_detection, which is used for current detection.

[0038] When the signal source port QS2 inputs low level, the transistor Q507 is not conductive, the first relay K507 has no current passing through, and QS2_OUT is connected to 24V_IN; when the signal source port QS2 inputs high level, the transistor Q507 is conductive, and the output of the second relay K507 is connected to the ground GND_Current_detection.

[0039] In the embodiment, it is assumed that the signal source port QS1 inputs low level and the signal source port QS2 inputs low level, as shown in Figure 1 、 Figure 2 and Figure 3 , the first relay K504 and the second relay K507 are both not closed, QS1_OUT and QS2_OUT are both connected to 24V_IN, and the target motor is not in action at this time.

[0040] It is assumed that the signal source port QS1 inputs low level and the signal source port QS2 inputs high level, the first relay K504 is not closed, the second relay K507 is closed, QS1_OUT is connected to 24V_IN, QS2_OUT is connected to the ground GND_Current_detection, and the target motor is in positive rotation at this time.

[0041] It is assumed that the signal source port QS1 inputs high level and the signal source port QS2 inputs low level, the first relay K504 is closed, the second relay K507 is not closed, QS1_OUT is connected to the ground GND_Current_detection, and QS2_OUT is connected to 24V_IN, and the target motor is in reverse rotation at this time.

[0042] As shown in Figure 4 , the ground GND_Current_detection is connected to the resistance R14 and then grounded, and when the current output through the ground passes through the resistance R14, a voltage drop will be generated between the two ends of the resistance, and this voltage drop is the detection voltage to be detected.

[0043] In the embodiment, the resistance R14 is a resistor with a resistance of 20 mΩ, a resistance tolerance of ±1%, and a rated power of 5 W. According to Ohm's law, when the current intensity is 3 A, the detection voltage = 3A x 0.02Ω = 0.06V, which means that when a current of 3 A passes through a resistance of 0.02Ω, a voltage drop of 0.06V will be generated between the two ends of the resistance.

[0044] The detection voltage is input into the non-inverting input terminal of the non-inverting amplifier, and the detection voltage will not be lost due to the high impedance of the input terminal of the operational amplifier. In order to realize signal amplification while keeping the phase of the input signal unchanged, the inverting input terminal of the non-inverting amplifier is connected to a gain circuit in this embodiment, and the gain circuit is composed of a resistor R4 and a resistor R5.

[0045] The calculation formula of the gain (G) in this embodiment is G = 1 + R5 / R4. The resistor R4 in this embodiment is an 82KΩ resistor, and the resistor R5 is a 5.1KΩ resistor. The calculated gain G is (1 + 82KΩ / 5.1KΩ) = 17.078431.

[0046] The output terminal of the non-inverting amplifier is connected to a designated detection port, and the designated detection port can collect the output current of the non-inverting amplifier through a multimeter, an oscilloscope or the like, so as to realize detection of the driving current of the target motor.

[0047] In this embodiment, the output terminal of the non-inverting amplifier is output by the designated detection port after passing through a low-pass filter composed of a resistor R1 and a capacitor C10. The designated detection port is connected to a controller unit (MCU) through an ADC module. The ADC module converts the analog signal into a digital signal through an internal A / D conversion circuit, so that the controller unit can process these signals. The controller unit is connected to the signal source port of the first driving circuit and the signal source port of the second driving circuit. The controller unit outputs corresponding level signals to the signal source ports of the driving circuits, so as to control the target motor to change its working state.

[0048] In this embodiment, the voltage value ADC_current corresponding to the designated detection port is equal to the detection voltage multiplied by the gain. Assuming that the detection voltage is 0.06V, then the voltage value ADC_current output after passing through the non-inverting amplifier is ADC_current = 0.06V * 17.078431 = 1.024V.

[0049] It should be noted that the A / D conversion circuit in the ADC module has been disclosed in the prior art, and will not be described in detail here.

[0050] In this embodiment, the controller unit collects the driving current of the target motor, and compares the collected current with a preset current threshold. If the collected current is greater than the current threshold, the controller unit outputs the same level signal to the signal source port QS1 of the first driving circuit and the signal source port QS2 of the second driving circuit, for example, simultaneously outputs a low level to the signal source port QS1 and the signal source port QS2. At this time, the first relay K504 and the second relay K507 are not closed, QS1_OUT and QS2_OUT are connected to 24V_IN, and there is no voltage difference across the target motor, so the target motor does not act.

[0051] It should be noted that the controller unit is an existing MCU chip, and the current comparison judgment process of the controller unit has been disclosed in the prior art, which can be executed according to the existing logic program, and the embodiment does not protect the controller unit itself and the judgment logic process of the controller unit.

[0052] Further, at the grounding point, TVS diode D8 and TVS diode D9 are also provided, which are connected in parallel between the grounding point and the non-inverting input terminal of the non-inverting amplifier, to realize input protection and improve the safety of the circuit.

[0053] In the design of the circuit in this embodiment, it is assumed that the maximum output voltage of the non-inverting amplifier is 3.3V, and the gain is 17.078431, so the maximum voltage value of the input terminal (i.e., GND_Current_detection) of the non-inverting amplifier under the maximum output voltage can be calculated as:

[0054] The maximum input voltage = 3.3V / 17.078431 ≈ 0.193V.

[0055] Using Ohm's law V = I x R, the maximum current I passing through the resistor R14 can be calculated as:

[0056] I = V / R = 0.193V / 0.02Ω ≈ 9.65A;

[0057] The actual power consumption P of the resistor R14 when passing through the current of 9.6A:

[0058] P = I 2 x R = 9.6A x 9.6A x 0.02Ω = 1.8432W.

[0059] Comparing the rated power consumption (5W) of the resistor R14 with the actual power consumption (1.8432W). Since 1.8432W is much smaller than 5W, it indicates that the resistor R14 has sufficient margin in design to handle this current and will not be damaged due to overheating, ensuring the safety and reliability of the circuit.

[0060] Embodiment Two

[0061] The present embodiment provides a pest situation forecasting instrument, which comprises a cleaning motor and the motor current detection circuit of embodiment one. The motor current detection circuit of embodiment one identifies the driving current size of the driving cleaning motor, and when the current is greater than the preset current threshold, the cleaning motor is controlled to stop working, thereby avoiding the continuous working of the cleaning motor under the condition of excessive current, which causes the circuit board line to be burned out, and playing a protection role.

[0062] The circuit structure and operation principle of the pest situation forecasting instrument in the embodiment of the utility model can be referred to the corresponding description in the above-mentioned embodiment one, which will not be repeated here.

[0063] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples, without contradiction.

[0064] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0065] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of various changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An electric motor current detection circuit, characterized by comprising: It comprises: at least two drive circuits; at least two relays, each of which is connected with its corresponding drive circuit, and one output end of each of the relays is connected with a target motor, and the other output end is provided with a grounding point for current detection; a resistor R14, the grounding point is grounded through the resistor R14, and the current output by the grounding point flows through the resistor R14 to generate a detection voltage; a non-inverting amplifier, the output end of the non-inverting amplifier is connected with a specified detection port; the detection voltage is input into the non-inverting amplifier for amplification and output to the specified detection port through the output end of the non-inverting amplifier.

2. The motor current sensing circuit of claim 1, wherein, The drive circuit comprises a resistor R514, a resistor R510, a resistor R515, and a triode Q504, the base of the triode Q504 is connected with the drive circuit through the resistor R510, the resistor R514 and the resistor R515 are connected between the base and the emitter of the triode Q504, and the emitter of the triode Q504 is grounded; the collector of the triode Q504 is connected with the relay.

3. The motor current sensing circuit of claim 1, wherein, The relay comprises a first relay and a second relay, the first relay is connected with the positive electrode of the target motor, the second relay is connected with the negative electrode of the target motor, and the first relay and the second relay are used for controlling the working state of the target motor, and the working state comprises pausing movement, positive rotation and reverse rotation.

4. The motor current sensing circuit of claim 1, wherein, It further comprises: a gain circuit composed of a resistor R4 and a resistor R5, which is connected with the reverse input end of the non-inverting amplifier.

5. The motor current sensing circuit of claim 1, wherein, It further comprises: a controller unit connected with the specified detection port, which is used for receiving an amplified voltage amplified by the non-inverting amplifier.

6. The motor current sensing circuit of claim 5, wherein, Each of the drive circuits has a corresponding signal source port, and the signal source port is connected with the controller unit.

7. The motor current sensing circuit of claim 1, wherein, The current detection circuit further comprises a TVS diode D8 and a TVS diode D9, which are connected in parallel between the grounding point and the non-inverting input end of the non-inverting amplifier.

8. A pest forecasting device, characterized by comprising: It comprises: a cleaning motor; the motor current detection circuit according to any one of claims 1-7, which is connected with the cleaning motor.

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