High-precision input voltage detection circuit

Abstract

The utility model discloses a high-precision input voltage detection circuit, the input voltage detection circuit comprises an acquisition unit, a driving unit and a detection unit, the acquisition unit is provided with a power supply connection port used for connecting an input power supply, the driving unit is respectively connected with the acquisition unit and the detection unit, and the detection unit is connected with the power supply connection port. The detection unit is provided with a detection output port used for being connected with the micro-control unit. The acquisition unit is used for acquiring an input voltage of an input power supply and performing voltage reduction processing on the input voltage, the driving unit drives the detection unit in a fixed-length time by taking the acquired input voltage as a reference, and the detection unit outputs detection data through the detection output port according to the driven fixed-length time. After the scheme is adopted, the on-off state of the input power supply can be detected, and the magnitude of the input voltage of the input power supply can be judged.

Description

Technical Field

[0001] This utility model relates to the technical field of input voltage detection circuits, and in particular to a high-precision input voltage detection circuit. Background Technology

[0002] Electrical equipment requires an input power supply during operation and performs various functions under the control of a microcontroller unit (MCU). To ensure safe operation, prevent malfunctions, improve product quality, and comply with regulations, the input voltage of the power supply is typically monitored. The monitoring results are used to help resolve power supply issues such as power on / off switching, voltage instability, and excessive current.

[0003] However, through observation, it was found that the existing input voltage detection circuit can only determine the on / off state of the input power supply by detecting whether there is an input voltage, and cannot accurately detect the magnitude of the input voltage of the input power supply.

[0004] In view of this, the designer has deeply conceived and actively researched and improved the design of the above-mentioned input voltage detection circuit, which has caused many deficiencies and inconveniences due to its imperfections. This led to the development and design of this utility model. Utility Model Content

[0005] The purpose of this invention is to provide a high-precision input voltage detection circuit for determining the magnitude of the input voltage of the input power supply.

[0006] To achieve the above objectives, the solution of this utility model is:

[0007] A high-precision input voltage detection circuit includes a data acquisition unit, a driving unit, and a detection unit. The data acquisition unit has a power connection port for connecting to an input power supply. The driving unit is connected to both the data acquisition unit and the detection unit. The detection unit has a detection output port for connecting to a microcontroller unit. The data acquisition unit acquires the input voltage of the input power supply and performs voltage step-down processing on the input voltage. The driving unit drives the detection unit for a fixed time period using the acquired input voltage as a reference. The detection unit outputs detection data through the detection output port according to the fixed time period of driving.

[0008] Preferably, the acquisition unit includes a step-down module and a shunt module, the driving unit includes a reference module and a driving module, and the detection unit includes a detection power supply module, a high-level module, and a low-level module; the step-down module is connected to a power connection port for connecting to the input power supply; one end of the shunt module and the reference module are respectively connected to the step-down module, and the other end is connected through the driving module; one end of the high-level module and the low-level module are connected through the driving module, and the other end is connected to the detection output port for connecting to the microcontroller unit; the power supply module is connected to the high-level module.

[0009] Preferably, the step-down module includes resistors R1, R2, and R3; the shunt module includes resistors R4 and R5; the reference module includes a controllable precision voltage regulator IC1; the drive module includes an optocoupler U1; the detection power supply module includes a DC power supply; the high-level module includes resistors R6 and R7; the low-level module includes a field-effect transistor Q1, resistors R8 and R9; resistors R3, R2, R1, R4, and R5 are connected in series, with one pin of resistor R5 connected to the anode pin of the LED in optocoupler U1, and the other pin of resistor R3 connected to the anode pin of controllable precision voltage regulator IC1; the cathode pin of controllable precision voltage regulator IC1 is connected to the optocoupler... The cathode pin of the LED in U1 is connected, and its reference pin is connected to the junction of resistors R3 and R2; the junction of resistors R1 and R4 and the anode pin of the controllable precision voltage regulator IC1 are respectively connected to the power supply port; the collector of the phototransistor in the optocoupler U1 is connected to the drain of the field-effect transistor Q1 through resistor R8; the gate of the field-effect transistor Q1 is connected to the emitter of the phototransistor in the optocoupler U1 through resistor R6; the source of the field-effect transistor Q1 is connected to the ground terminal GND, and is also connected to the gate of the field-effect transistor Q1 through resistor R9; the detection output port is connected to the drain of the field-effect transistor Q1 through resistor R7; the anode of the DC power supply DC is connected to the collector of the phototransistor in the optocoupler U1.

[0010] Preferably, the acquisition unit further includes a protection module, which includes a diode D1, and the connection point of the resistors R1 and R4 is connected to the power connection port through the diode D1.

[0011] Preferably, the driving unit further includes a filtering module, which includes a capacitor C1 and a resistor R10; one end of the capacitor C1 is connected to the connection point of resistors R2 and R3, and the other end of the capacitor C1 is connected to the anode pin of the controllable precision voltage regulator IC1; the reference terminal of the controllable precision voltage regulator IC1 is connected to the connection point of resistors R2 and R3 through resistor R10.

[0012] Preferably, the controllable precision voltage regulator IC1 is a TL431 controllable precision voltage regulator.

[0013] Preferably, the optocoupler U1 is a PC817 optocoupler.

[0014] The principle of detecting the input voltage of the input power supply using the above scheme is as follows: when the input power supply is in an open circuit state, the input voltage is 0, the controllable precision voltage regulator IC1 is always in a cutoff state, the optocoupler U1 is always in a cutoff state, and the DC power supply DC always outputs a high-level signal through the high-level module and the detection output port, thereby determining that the input power supply is in an open circuit state.

[0015] When the input power supply is in a closed state and the input voltage is greater than 2.5V, the controllable precision voltage regulator IC1 will have a conduction time, the optocoupler U1 will also have a conduction time, and the DC power supply will output a low-level signal through the low-level module and the detection output port, thereby determining that the input power supply is in a closed state.

[0016] When the input power supply is on and the input voltage is greater than 2.5V, according to the sinusoidal waveform of the input voltage, when the real-time voltage is less than 2.5V, the controllable precision voltage regulator IC1 is always in the off state, the optocoupler U1 is always in the off state, and the DC power supply DC always outputs a high-level signal through the high-level module and the detection output port. When the real-time voltage is greater than 2.5V, the controllable precision voltage regulator IC1 has a conduction time, the optocoupler U1 also has a conduction time, and the DC power supply DC outputs a low-level signal through the low-level module and the detection output port. The relationship between the real-time voltage and the detection time is a square wave signal that alternates between "high level" and "low level". Furthermore, when the input voltage is larger, the duration of the low-level signal output by the detection output port is longer, and the duty cycle of the square wave signal is smaller. Therefore, it can be determined that the smaller the duty cycle of the square wave signal, the larger the input voltage. Attached Figure Description

[0017] Figure 1 This is a circuit diagram of a preferred embodiment of the present invention.

[0018] Explanation of key component symbols:

[0019] In the diagram: 100, acquisition unit; 200, drive unit; 300, detection unit; 400, power connection port; 500, detection output port. Detailed Implementation

[0020] To further explain the technical solution of this utility model, the following detailed description is provided through specific embodiments.

[0021] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and 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, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0022] like Figure 1 As shown, this is a preferred embodiment of a high-precision input voltage detection circuit of the present invention. The input voltage detection circuit includes a data acquisition unit 100, a driving unit 200, and a detection unit 300. The data acquisition unit 100 is provided with a power connection port 400 for connecting to the input power supply. The driving unit 200 is connected to both the data acquisition unit 100 and the detection unit 300. The detection unit 300 is provided with a detection output port 500 for connecting to a microcontroller unit. The data acquisition unit 100 is used to acquire the input voltage of the input power supply and to step down the input voltage. The driving unit 200 drives the detection unit 300 for a certain period of time with the acquired input voltage as a reference. The detection unit 300 outputs detection data through the detection output port 500 according to the certain period of time it is driven.

[0023] The aforementioned acquisition unit 100 includes a step-down module and a shunt module; the drive unit 200 includes a reference module and a drive module; and the detection unit 300 includes a detection power supply module, a high-level module, and a low-level module. The step-down module is connected to the power connection port 400 for connecting to the input power supply. One end of the shunt module and the reference module are respectively connected to the step-down module, and the other end is connected through the drive module. One end of the high-level module and the low-level module are connected through the drive module, and the other end is connected to the detection output port 500 for connecting to the microcontroller unit. The power supply module is connected to the high-level module.

[0024] The aforementioned step-down module includes resistors R1, R2, and R3; the shunt module includes resistors R4 and R5; the reference module includes a controllable precision voltage regulator IC1; the drive module includes an optocoupler U1; the detection power supply module includes a DC power supply; the high-level module includes resistors R6 and R7; the low-level module includes a field-effect transistor Q1, resistors R8 and R9, and resistors R3, R2, R1, R4, and R5 connected in series. The other end of resistor R5 is connected to the anode pin of the LED in optocoupler U1, and the other end of resistor R3 is connected to the anode pin of the controllable precision voltage regulator IC1. The cathode pin of the controllable precision voltage regulator IC1 is connected to the cathode pin of the LED in optocoupler U1. The cathode pin is connected, and its reference pin is connected to the junction of resistors R3 and R2; the junction of resistors R1 and R4 is connected to the anode pin of the controllable precision voltage regulator IC1 and then to the power supply connection port 400; the collector of the phototransistor in the optocoupler U1 is connected to the drain of the field-effect transistor Q1 through resistor R8; the gate of the field-effect transistor Q1 is connected to the emitter of the phototransistor in the optocoupler U1 through resistor R6; the source of the field-effect transistor Q1 is connected to the ground terminal GND, and is also connected to the gate of the field-effect transistor Q1 through resistor R9; the detection output port 500 is connected to the drain of the field-effect transistor Q1 through resistor R7; the anode of the DC power supply DC is connected to the collector of the phototransistor in the optocoupler U1.

[0025] In use, the input voltage detection circuit of this utility model is connected to the input power supply through the power connection port 400 and to the analog-to-digital converter pin of the microcontroller unit (MCU) through the detection output port 500, in order to detect the input voltage of the input power supply.

[0026] In this embodiment, the controllable precision voltage regulator IC1 is a TL431 controllable precision voltage regulator. The optocoupler U1 is a PC817 optocoupler.

[0027] The principle of detecting the input voltage of the input power supply is that when the input power supply is in an open circuit state, the input voltage is 0, the controllable precision voltage regulator IC1 is always in a cutoff state, the optocoupler U1 is always in a cutoff state, and the DC power supply DC always outputs a high-level signal through the high-level module and the detection output port 500, thereby determining that the input power supply is in an open circuit state.

[0028] When the input power supply is in a closed state and the input voltage is greater than 2.5V, the controllable precision voltage regulator IC1 will have a conduction time, the optocoupler U1 will also have a conduction time, and the DC power supply will output a low-level signal through the low-level module and the detection output port 500, thereby determining that the input power supply is in a closed state.

[0029] When the input power supply is on and the input voltage is greater than 2.5V, according to the sinusoidal waveform of the input voltage, when the real-time voltage is less than 2.5V, the controllable precision voltage regulator IC1 is always in the off state, the optocoupler U1 is always in the off state, and the DC power supply DC always outputs a high-level signal through the high-level module and the detection output port 500. When the real-time voltage is greater than 2.5V, the controllable precision voltage regulator IC1 has a conduction time, the optocoupler U1 also has a conduction time, and the DC power supply DC outputs a low-level signal through the low-level module and the detection output port 500. The relationship between the real-time voltage and the detection time is a square wave signal that alternates between "high level - low level". Furthermore, when the input voltage is larger, the duration of the low-level signal output by the detection output port 500 is longer, and the duty cycle of the square wave signal is smaller. Therefore, it can be determined that the smaller the duty cycle of the square wave signal, the larger the input voltage.

[0030] The aforementioned acquisition unit 100 also includes a protection module, which includes a diode D1. The connection point of resistors R1 and R4 is connected to the power connection port 400 through diode D1. In this way, diode D1 can prevent the input power supply polarity from being reversed. If the positive and negative terminals of the input power supply are reversed, diode D1 will block the current from flowing through the circuit, thereby protecting the circuit from damage.

[0031] The aforementioned driving unit 200 also includes a filtering module, which comprises a capacitor C1 and a resistor R10. One pin of capacitor C1 is connected to the junction of resistors R2 and R3, and the other pin is connected to the anode pin of the controllable precision voltage regulator IC1. The reference terminal of the controllable precision voltage regulator IC1 is connected to the junction of resistors R2 and R3 via resistor R10. Thus, capacitor C1 and resistor R10 can form an RC circuit, used as a low-pass filter. When the input signal frequency is high, the capacitive reactance of capacitor C1 is small, and the signal is easily short-circuited through capacitor C1, while low-frequency signals can be output through the path formed by resistor R10 and capacitor C1. Therefore, the RC circuit can effectively filter out high-frequency noise or interference signals while retaining low-frequency signals.

[0032] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the present invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the present invention and its practical applications, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments and various choices and variations of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A high-precision input voltage detection circuit, characterized in that: The input voltage detection circuit comprises a collection unit (100), a driving unit (200) and a detection unit (300), the collection unit (100) is provided with a power connection port (400) for connecting an input power supply, the driving unit (200) is connected with the collection unit (100) and the detection unit (300) respectively, and the detection unit (300) is provided with a detection output port (500) for connecting a micro control unit; the collection unit (100) is used for collecting an input voltage of the input power supply and performing voltage reduction processing on the input voltage, the driving unit (200) drives the detection unit (300) in a fixed length time by taking the collected input voltage as a reference, and the detection unit (300) outputs detection data through the detection output port (500) according to the fixed length time being driven.

2. The high-precision input voltage detection circuit of claim 1, wherein: The collection unit (100) comprises a voltage reduction module and a shunt module, the driving unit (200) comprises a reference module and a driving module, and the detection unit (300) comprises a detection power supply module, a high level module and a low level module. The voltage reduction module is connected with the power connection port (400) and used for connecting the input power supply, one end of the shunt module and the reference module is connected to the voltage reduction module, and the other end is connected through the driving module; one end of the high level module and the low level module is connected through the driving module, and the other end is connected to the detection output port (500) and used for connecting the micro control unit; and the detection power supply module is connected with the high level module.

3. A high-precision input voltage detection circuit according to claim 2, characterized in that: The voltage reduction module comprises resistors R1, R2 and R3, the shunt module comprises resistors R4 and R5, the reference module comprises a controllable precision voltage stabilizer IC1, the driving module comprises a photoelectric coupler U1, the detection power supply module comprises a direct current power supply DC, the high level module comprises resistors R6 and R7, and the low level module comprises a field effect tube Q1, resistors R8 and R9. The resistance R3, resistance R2, resistance R1, resistance R4, resistance R5 are connected in series, the other end pin of the resistance R5 is connected with the anode pin of the light emitting diode in the photoelectric coupler U1, the other end pin of the resistance R3 is connected with the anode pin of the controllable precision voltage regulator IC1; the cathode pin of the controllable precision voltage regulator IC1 is connected with the cathode pin of the light emitting diode in the photoelectric coupler U1, the reference pin thereof is connected with the connection point of the resistance R3 and the resistance R2; the connection point of the resistance R1 and the resistance R4 is connected with the anode pin of the controllable precision voltage regulator IC1 and the power connection port (400) respectively; the collector of the photoelectric triode in the photoelectric coupler U1 is connected with the drain of the field effect tube Q1 through the resistance R8; the gate of the field effect tube Q1 is connected with the emitter of the photoelectric triode in the photoelectric coupler U1 through the resistance R6; the source of the field effect tube Q1 is connected with the ground terminal GND, and is further connected with the gate of the field effect tube Q1 through the resistance R9; the detection output port (500) is connected with the drain of the field effect tube Q1 through the resistance R7; the anode of the direct current power supply DC is connected with the collector of the photoelectric triode in the photoelectric coupler U1.

4. The high-precision input voltage detection circuit of claim 3, wherein: The collection unit (100) further comprises a protection module, the protection module comprises a diode D1, and the connection point of the resistance R1 and the resistance R4 is connected with the power connection port (400) through the diode D1.

5. The high-precision input voltage detection circuit of claim 3, wherein: The driving unit (200) further comprises a filtering module, the filtering module comprises a capacitor C1 and a resistance R10; one end pin of the capacitor C1 is connected with the connection point of the resistance R2 and the resistance R3, and the other end pin thereof is connected with the anode pin of the controllable precision voltage regulator IC1; the reference of the controllable precision voltage regulator IC1 is connected with the connection point of the resistance R2 and the resistance R3 through the resistance R10.

6. The high-precision input voltage detection circuit of claim 3, wherein: The controllable precision voltage regulator IC1 is a TL431 controllable precision voltage regulator.

7. The high-precision input voltage detection circuit of claim 3, wherein: The photoelectric coupler U1 is a PC817 photoelectric coupler.

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