Current and voltage integrated physics teaching sensor

Abstract

The utility model discloses a current and voltage integrated physics teaching sensor comprising a mainboard, an ADC analog-to-digital converter, a switching module and a power supply module, the output end of the mainboard is connected with the input end of the switching module, the output end of the switching module is connected with the input end of the ADC analog-to-digital converter, and the output end of the switching module is connected with the input end of the ADC analog-to-digital converter. The output end of the ADC analog-to-digital converter is connected to the input end of the mainboard, the power supply module is connected with the mainboard and the switching module, and the power supply module is used for providing an operation power supply. According to the utility model, the relay is adopted as a switch switching circuit, and the mainboard is externally connected with the key, so that the mainboard can send a control signal to the relay while switching function menus, and the relay on the switching board is enabled to conduct a corresponding circuit, thereby achieving the purpose that different electric sensors can be switched only by pressing the key for a long time.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, and in particular to an integrated current and voltage physics teaching sensor. Background Technology

[0002] Portable measurement sensors are devices used for data acquisition and analysis in various environments. While they come in various types depending on the measurement requirements, they are essentially devices where a central board continuously replaces external receiving boards to collect data, which is then manually converted into code and processed by the mainboard. However, existing portable measurement sensors have the following shortcomings:

[0003] There are significant drawbacks in sensor switching. Users cannot freely switch between different sensors, making each switching operation extremely inconvenient and often requiring a complex manual switching process, which severely impacts the user experience. Regarding current and voltage measurements, if a sensor needs to switch between current and voltage measurement modes, current technologies either require two independent sensors, which undoubtedly increases product cost and resource consumption, or require users to re-power on and reprogram the device, an overly complex operation. Furthermore, during sensor switching, because the sensor requires DIP switch 2 to be in the ON position, unfamiliar users may accidentally set the sensor to current and forget to toggle the switch, easily leading to errors that could burn out the sampling ADC circuit. As the ADC circuit is a critical component, once it burns out, the entire motherboard loses its basic functionality, rendering the entire sensor unusable. This requires users to be proficient in the operating procedures; otherwise, even a slight mistake could render the entire sensor unusable, causing great inconvenience and economic losses to users, and greatly increasing the consumption of human and material resources. In particular, during the teaching process, students are more likely to encounter the above problems due to their lack of operating skills. The root cause of these problems lies in the fact that the switching schemes used by the relevant products are too complicated. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides an integrated current and voltage physics teaching sensor. By using a relay as a switch, the sensor can be switched to current or voltage measurement mode to prevent users from making mistakes or forgetting the steps, which could lead to the sensor becoming unusable.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] This utility model discloses an integrated current and voltage physics teaching sensor, comprising a motherboard, an ADC analog-to-digital converter, a switching module, and a power supply module. The output terminal of the motherboard is connected to the input terminal of the switching module, the output terminal of the switching module is connected to the input terminal of the ADC analog-to-digital converter, the output terminal of the ADC analog-to-digital converter is connected to the input terminal of the motherboard, and the power supply module is connected to both the motherboard and the switching module, and the power supply module is used to provide operating power.

[0007] In a preferred embodiment of this utility model, the switching module includes a switching circuit, which includes relays K1, K2, and K3. Pin 1 of relay K1 is connected to the anode of switching diode D3 and to the positive terminal of a 3.3V power supply. Pin 4 of relay K1 is connected to the cathode of switching diode D3 and the collector of transistor Q3. The base of transistor Q3 is connected to one end of resistor R8 and one end of resistor R9. The other end of resistor R8 is connected to the emitter of transistor Q3 and to the negative terminal of a 3.3V power supply. The other end of resistor R9 is connected to an I / O port on the motherboard. The relay K1... Pin 5 of relay K1 is connected to one end of resistor R4 and one end of resistor R5, respectively. The other end of resistor R4 is connected to the positive terminal of the 3V power supply. The other end of resistor R5 serves as the GND test terminal and is connected to the negative terminal of the 3V power supply. Pin 3 of relay K1 is normally closed. Pin 2 of relay K1 serves as the A1 test terminal and is connected to pin 5 of relay K2 and pin 5 of relay K3, respectively. Pin 1 of relay K2 is connected to the anode of switching diode D1 and is connected to the positive terminal of the 3.3V power supply. Pin 4 of relay K2 is connected to the cathode of switching diode D1 and the collector of transistor Q1, respectively. The base of transistor Q1 is connected to... One end of resistor R2 and one end of resistor R1 are connected. The other end of resistor R1 is connected to the I / O port of the motherboard. The other end of resistor R2 is connected to the emitter of transistor Q1 and to the negative terminal of the 3.3V power supply. Pin 3 of relay K2 is normally closed. Pin 2 of relay K2 is connected to one end of current-measuring resistor U2. Pin 1 of relay K3 is connected to the anode of switching diode D2 and to the positive terminal of the 3.3V power supply. Pin 4 of relay K3 is connected to the cathode of switching diode D2 and the collector of transistor Q2. The base of transistor Q2 is connected to one end of resistor R3 and one end of resistor R7. The other end of resistor R3 is connected to the I / O port of the motherboard. The other end of resistor R7 is connected to the emitter of transistor Q2 and to the negative terminal of the 3.3V power supply. Pin 3 of relay K3 is normally closed. Pin 2 of relay K3 is connected to one end of resistor R6. The other end of current-measuring resistor U2 is connected to the other end of resistor R6 and serves as the A0 test terminal. The system also includes a power strip U6. The GND test terminal, A0 test terminal, and A1 test terminal are connected to pins 1, 2, and 3 of power strip U6, respectively. Pin 4 of power strip U6 is connected to the positive terminal of the 3V power supply. Pins 1, 5, and 6 of power strip U6 are all connected to the negative terminal of the 3V power supply.

[0008] As a preferred embodiment of this utility model, the switching circuit further includes a preset group, which includes group U1 and group U4. The other end of the resistor R9 is also connected to pin 2 of group U4 and connected to the I / O port of the motherboard. Pin 3 of group U4 is connected to the positive terminal of the 3.3V power supply, and pins 1, 5 and 6 of group U4 are all connected to the negative terminal of the 3.3V power supply. The other ends of the resistor R1 and the other ends of the resistor R3 are also connected to pins 2 and 3 of group U1 respectively and connected to the I / O port of the motherboard. Pin 4 of group U1 is connected to the positive terminal of the 3.3V power supply, and pins 1, 5 and 6 of group U1 are all connected to the negative terminal of the 3.3V power supply.

[0009] By adopting the above technical solution, this utility model has the following beneficial effects:

[0010] 1. This utility model uses a relay as a switching circuit. An external input button can be connected to the motherboard. When the input button is pressed, the motherboard sends a control signal to the relay to activate the corresponding relay. Different activation modes of the relay form different measurement modes, enabling the switching circuit to measure the current or voltage of the external circuit. This achieves the goal of switching between different electrical sensors simply by pressing and holding the button, realizing simultaneous switching of hardware and software without additional operation. This not only improves the user experience but also prevents sensor burnout and scrap due to incorrect operation or forgetting the steps, thus enhancing the safety and reliability of the sensor.

[0011] 2. The addition of a preset group in this utility model allows the switching circuit to be extended to connect to other sensors in order to measure other physical quantities. Attached Figure Description

[0012] Figure 1 This is a functional flowchart of this utility model.

[0013] Figure 2 This is a circuit diagram of the switching circuit of this utility model.

[0014] Figure 3 This is a diagram of the internal structure, schematic diagram, and PCB layout of the relay of this utility model.

[0015] Figure 4 This is the circuit diagram of the ADC analog-to-digital converter of this utility model. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0017] The current-voltage integrated physics teaching sensor of this embodiment includes a motherboard 1, an ADC analog-to-digital converter 2, a switching module 3, and a power supply module 4. The output terminal of the motherboard 1 is connected to the input terminal of the switching module 3, and the output terminal of the switching module 3 is connected to the input terminal of the ADC analog-to-digital converter 2. The output terminal of the ADC analog-to-digital converter 2 is connected to the input terminal of the motherboard 1. The power supply module 4 is connected to both the motherboard 1 and the switching module 3. The power supply module 4 is used to provide operating power, specifically outputting 3.3V control power and 3V startup power to the motherboard 1 and the switching module 4, respectively.

[0018] The switching module 4 includes a switching circuit, which comprises relays K1, K2, K3, and group U6. Specifically, relays K1, K2, and K3 are all 5-pin relays. The 5-pin relay is an existing technology and is briefly described as follows: The relay starting voltage is 3V. Relay pins 1 and 4 are connected to the positive and negative control input voltages. Relay pin 3 is normally closed, relay pin 2 is normally open, and relay pin 5 is a common terminal. When the voltage between relay pins 1 and 4 is 0V, relay pins 3 and 5 are connected. After the control voltage is applied between relay pins 1 and 4, relay pins 2 and 5 are connected.

[0019] Pin 1 of relay K1 is connected to the anode of switching diode D3 and to the positive terminal of a 3.3V power supply. Pin 4 of relay K1 is connected to the cathode of switching diode D3 and the collector of transistor Q3. The base of transistor Q3 is connected to one end of resistor R8 and one end of resistor R9. The other end of resistor R8 is connected to the emitter of transistor Q3 and to the negative terminal of a 3.3V power supply. The other end of resistor R9 is connected to the I / O port of motherboard 1. Pin 5 of relay K1 is connected to one end of resistor R4 and one end of resistor R5. The other end of resistor R4... One end of resistor R5 is connected to the positive terminal of a 3V power supply. The other end of resistor R5 serves as the GND test terminal and is connected to pin 1 of the power supply U6. Pin 3 of relay K1 is normally closed. Pin 2 of relay K1 serves as the A1 test terminal and is connected to pins 5 of relays K2 and K3 respectively, and also to pin 3 of the power supply U6. Pin 1 of relay K2 is connected to the anode of switching diode D1 and to the positive terminal of the 3.3V power supply. Pin 4 of relay K2 is connected to the cathode of switching diode D1 and the collector of transistor Q1 respectively. The base of transistor Q1 is connected to the cathode of switching diode D1 and the collector of transistor Q1 respectively. Do not connect one end of resistor R2 to one end of resistor R1. Connect the other end of resistor R1 to the I / O port of motherboard 1. Connect the other end of resistor R2 to the emitter of transistor Q1 and to the negative terminal of the 3.3V power supply. Pin 3 of relay K2 is normally closed. Pin 2 of relay K2 is connected to one end of current-measuring resistor U2. Pin 1 of relay K3 is connected to the anode of switching diode D2 and to the positive terminal of the 3.3V power supply. Pin 4 of relay K3 is connected to the cathode of switching diode D2 and the collector of transistor Q2. The base of transistor Q2 is connected to... One end of resistor R3 is connected to one end of resistor R7. The other end of resistor R3 is connected to the I / O port of motherboard 1. The other end of resistor R7 is connected to the emitter of transistor Q2 and to the negative terminal of 3.3V power supply. Pin 3 of relay K3 is normally closed. Pin 2 of relay K3 is connected to one end of resistor R6. The other end of current measuring resistor U2 is connected to the other end of resistor R6 and serves as the A0 test terminal, connected to pin 2 of power supply U6. Pin 4 of power supply U6 is connected to the positive terminal of 3V power supply. Pins 1, 5, and 6 of power supply U6 are all connected to the negative terminal of 3V power supply. The aforementioned switching circuit connects the base of the transistor to the I / O port of the motherboard 1. The signal output from the motherboard 1 can control the conduction and cutoff of the transistor, thereby controlling the flow of a larger current and driving the corresponding relay as a switch. When the pin corresponding to the base of the transistor outputs a high level, the transistor conducts, the relay coil is energized, and the relay contacts close. When the output is low, the transistor is cut off, the relay coil is de-energized, and the relay contacts open. A resistor is connected in series between the base and emitter of the transistor to protect the base and prevent the transistor from malfunctioning due to noise signals.

[0020] Preferably, transistors Q1, Q2, and Q3 are all NPN transistors with the commercial model S8050-J3Y, used as the switch to drive the relay; switching diodes D1, D2, and D3 are all diodes with the commercial model 1N4007W, used as freewheeling diodes to protect the transistors from breakdown; resistors R1, R3, and R9 have a resistance of 1KΩ, serving as current-limiting resistors to prevent high voltage surges to the motherboard 1; resistors R2, R4, R5, R7, and R8 have a resistance of 10KΩ, with resistors R2, R7, and R8 serving as pull-down resistors to prevent relay malfunction; resistor R6 has a resistance of 100KΩ; and current-measuring resistor U2 has a resistance of 0.14Ω.

[0021] Relay conduction status and input mode: Relay K1 is on, adding a potential difference of 1.5V between test terminals A0 and A1 for measuring positive and negative voltage; Relay K2 is on, connecting a 0.14Ω current-measuring resistor U2 in parallel between test terminals A0 and A1, allowing test terminals A0 and A1 to be used for current measurement; Relay 3 is on, connecting a 100kΩ resistor R6 in parallel between test terminals A0 and A1 to balance the voltage difference. When the relay combination is conducting, there are three modes: ① When relays K1, K2, and K3 are all off, it is a single-ended input mode, with the A0 test terminal as the positive terminal and the GND test terminal as the negative terminal. This sensor can only measure positive voltage or positive current. ② When relays K1 and K3 are conducting and relay K2 is off, it is a dual-ended input mode, with the A0 test terminal as the positive terminal and the A1 test terminal as the negative terminal. This sensor measures positive and negative voltage. ③ When relays K1 and K2 are conducting and relay K3 is off, it is a current measurement mode, with the A0 test terminal as the positive terminal and the A1 test terminal as the negative terminal. This sensor measures positive and negative current.

[0022] The sensor operation process of this utility model is as follows: An external input button is connected to the main board 1. When the button switch is closed, the main board 1 detects the button action and generates a control signal, which is then output to the switching circuit. The relay in the switching circuit is switched on and off via the control signal to switch between different modes of current and voltage sensors. The A0, A1, and GND test terminals can be connected to external probes via the U6 connector to measure external circuits under test. The generated voltage or current analog signals are output to the ADC analog-to-digital converter 3 for processing and conversion into digital signals before being output to the main board 1 for further processing.

[0023] It should be noted that the ADC analog-to-digital converter 3 utilizes existing technology, specifically the commercially available ADS1120-Q1. A brief explanation follows: The ADS1120-Q1 is a 16-bit ADC with two differential inputs or four single-ended inputs implemented via a flexible input multiplexer (MUX), a low-noise programmable gain amplifier (PGA), two programmable magnetizing current sources, a voltage reference, an oscillator, a low-side switch, and a precision temperature sensor. By selecting the ADS1120 chip as the ADC sampling chip, its integrated features reduce the cost of the sensor system and the number of components in sensor signal measurement applications, enabling high-precision voltage sampling and improving measurement accuracy and reliability.

[0024] Based on the aforementioned scheme, as a preferred embodiment, the switching circuit further includes preset groups, which include groups U1 and U6. The other end of resistor R9 is connected to pin 2 of group U4, which is connected to the positive terminal of a 3.3V power supply. Pin 3 of group U4 is also connected to the positive terminal of a 3.3V power supply. Pins 1, 5, and 6 of group U4 are all connected to the negative terminal of a 3.3V power supply. The other ends of resistors R1 and R3 are connected to pins 2 and 3 of group U1, respectively. Pin 4 of group U1 is connected to the positive terminal of a 3.3V power supply, and pins 1, 5, and 6 of group U1 are all connected to the negative terminal of a 3.3V power supply. The transistor is connected to the motherboard's I / O pins via the preset resistor array, simplifying the circuit's physical layout and design. Furthermore, the preset resistor array can also serve as an expansion interface, allowing the connection of different sensors to measure other physical quantities, such as piezoelectric sensors and ultrasonic sensors, thus expanding measurement capabilities and improving the flexibility of circuit design based on the switching circuit.

[0025] As mentioned earlier, this invention uses a relay as the switching circuit. Through an external input button on the motherboard, the motherboard can send a control signal to the relay while switching function menus, causing the relay in the switching module to conduct the corresponding circuit. This allows for switching between different electrical sensors simply by pressing and holding the button, achieving simultaneous hardware and software switching without additional operation. This not only improves the user experience but also prevents sensor burnout due to incorrect operation or forgetting steps, enhancing sensor safety and reliability. Furthermore, the addition of preset arrays allows the switching circuit to be expanded to connect other components for measuring other physical quantities. This multi-functional design reduces purchase costs, and the use of affordable components further reduces manufacturing costs.

[0026] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A current-voltage integrated physics teaching sensor, characterized in that: The system includes a motherboard (1), an ADC analog-to-digital converter (2), a switching module (3), and a power supply module (4). The output of the motherboard (1) is connected to the input of the switching module (3), the output of the switching module (3) is connected to the input of the ADC analog-to-digital converter (2), the output of the ADC analog-to-digital converter (2) is connected to the input of the motherboard (1), and the power supply module (4) is connected to both the motherboard (1) and the switching module (3). The power supply module (4) is used to provide operating power.

2. The current-voltage integrated physics teaching sensor according to claim 1, characterized in that: The switching module (3) includes a switching circuit, which includes relays K1, K2, and K3. Pin 1 of relay K1 is connected to the anode of switching diode D3 and to the positive terminal of a 3.3V power supply. Pin 4 of relay K1 is connected to the cathode of switching diode D3 and the collector of transistor Q3, respectively. The base of transistor Q3 is connected to one end of resistor R8 and one end of resistor R9, respectively. The other end of resistor R8 is connected to the emitter of transistor Q3 and to the negative terminal of a 3.3V power supply. The other end of resistor R9 is connected to the IO port of the motherboard (1). Pin 5 of relay K1 is connected to... One end of resistor R4 and one end of resistor R5 are connected. The other end of resistor R4 is connected to the positive terminal of the 3V power supply. The other end of resistor R5 serves as the GND test terminal and is connected to the negative terminal of the 3V power supply. Pin 3 of relay K1 is normally closed. Pin 2 of relay K1 serves as the A1 test terminal and is connected to pin 5 of relay K2 and pin 5 of relay K3, respectively. Pin 1 of relay K2 is connected to the anode of switching diode D1 and is connected to the positive terminal of the 3.3V power supply. Pin 4 of relay K2 is connected to the cathode of switching diode D1 and the collector of transistor Q1, respectively. The base of transistor Q1 is connected to one end of resistor R2. One end of resistor R1 is connected to the other end of resistor R1, and the other end of resistor R2 is connected to the IO port of the motherboard (1). The other end of resistor R2 is connected to the emitter of transistor Q1 and to the negative terminal of the 3.3V power supply. Pin 3 of relay K2 is normally closed. Pin 2 of relay K2 is connected to one end of current-measuring resistor U2. Pin 1 of relay K3 is connected to the anode of switching diode D2 and to the positive terminal of the 3.3V power supply. Pin 4 of relay K3 is connected to the cathode of switching diode D2 and the collector of transistor Q2. The base of transistor Q2 is connected to one end of resistor R3 and one end of resistor R7. The other end of 3 is connected to the IO port of the motherboard (1). The other end of the resistor R7 is connected to the emitter of the transistor Q2 and to the negative terminal of the 3.3V power supply. The pin 3 of the relay K3 is normally closed. The pin 2 of the relay K3 is connected to one end of the resistor R6. The other end of the current measuring resistor U2 is connected to the other end of the resistor R6 and serves as the A0 test terminal. It also includes a group U6. The GND test terminal, A0 test terminal and A1 test terminal are connected to the pins 1, 2 and 3 of the group U6, respectively. The pin 4 of the group U6 is connected to the positive terminal of the 3V power supply. The pins 1, 5 and 6 of the group U6 are all connected to the negative terminal of the 3V power supply.

3. The current-voltage integrated physics teaching sensor according to claim 2, characterized in that: The switching circuit also includes a preset group, which includes group U1 and group U4. The other end of the resistor R9 is also connected to pin 2 of group U4 and connected to the IO port of the motherboard (1). Pin 3 of group U4 is connected to the positive terminal of 3.3V power supply. Pins 1, 5 and 6 of group U4 are all connected to the negative terminal of 3.3V power supply. The other end of the resistor R1 and the other end of the resistor R3 are also connected to pins 2 and 3 of group U1 and connected to the IO port of the motherboard (1). Pin 4 of group U1 is connected to the positive terminal of 3.3V power supply. Pins 1, 5 and 6 of group U1 are all connected to the negative terminal of 3.3V power supply.

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