Sampling voltage-dividing constant-voltage protection circuit

Abstract

The utility model relates to the technical field of voltage sampling circuit design, in particular to a sampling voltage-dividing constant-voltage protection circuit which comprises a resistance voltage-dividing circuit which comprises a Schottky diode DI1, a voltage-dividing unit, a grounding capacitor C1 and a voltage-regulating resistor RI7. The Schottky diode DI1, the voltage dividing unit, the grounding capacitor C1 and the voltage regulating resistor RI7 are connected with an ADC pin SICIN of the single-chip microcomputer. The input end of the voltage dividing unit is connected with an ATS upper port voltage, one end of the voltage regulating resistor RI7 is connected with a + 1.65 V1 voltage, and one end of the Schottky diode DI1 is connected with a + 3.3 VA1 voltage. By adopting the protection circuit structure, complex electronic components such as an operational amplifier are omitted, the circuit design is simplified, and the cost is reduced. Meanwhile, the sampling precision can be ensured, and the low-cost and low-voltage acquisition of the voltage of the upper port of the ATS is effectively realized, and the voltage can be identified by the ADC port of the single-chip microcomputer.

Description

Technical Field

[0001] The utility model relates to the technical field of voltage sampling circuit design, in particular to a sampling voltage-dividing constant-voltage protection circuit. Background Art

[0002] The main working principle of dual power supply product control is to collect the voltage of the ATS upper port and add certain conditions to judge, such as loss of voltage, undervoltage, overvoltage, and phase failure to control the conversion of ATS, to ensure that the product can be converted when the power supply voltage is abnormal, and to ensure the continuity of power supply. Therefore, voltage sampling is an important part of ATS, and the accuracy of sampling must be guaranteed to accurately identify the abnormality of the upper port.

[0003] In the application field of ATS products, the upper port voltage connected to the products is high voltage ≥220V, but the sampling chips generally used are mostly single-chip microcomputers for direct sampling or metering chips for sampling. The input voltage of these chips is weak current, so it is necessary to convert the upper port voltage into weak current that the chip can identify. Generally, the common high-voltage voltage divider circuits are mostly completed with operational amplifiers, but this method generally requires a more complex peripheral circuit and is more expensive. Summary of the invention

[0004] The utility model aims to solve the technical problem that the high voltage voltage divider circuits mentioned above are mostly completed by operational amplifiers, which are complex and costly.

[0005] In order to solve the above technical problems, the utility model provides a sampling voltage-dividing constant voltage protection circuit, comprising: a resistor voltage-dividing circuit, the resistor voltage-dividing circuit comprising a Schottky diode DI1, a voltage-dividing unit, a grounding capacitor C1 and a voltage-regulating resistor RI7, the Schottky diode DI1, the voltage-dividing unit, the grounding capacitor C1 and the voltage-regulating resistor RI7 are all connected to the ADC pin SIC_IN of the single-chip computer;

[0006] The input end of the voltage dividing unit is connected to the ATS upper port voltage, one end of the voltage regulating resistor RI7 is connected to the +1.65V1 voltage, and one end of the Schottky diode DI1 is connected to the +3.3VA1 voltage.

[0007] Preferably, the voltage dividing unit comprises 6 high-voltage voltage dividing resistors connected in series.

[0008] Preferably, the resistance value of each of the high-voltage voltage-dividing resistors is 1 MΩ.

[0009] Preferably, the resistance of the voltage regulating resistor RI7 does not exceed 22.5 KΩ.

[0010] Preferably, the sampling voltage-dividing constant voltage protection circuit further includes a power supply voltage stabilizing circuit, and the power supply voltage stabilizing circuit includes a filter capacitor CK1, a magnetic bead LK1, a voltage stabilizing capacitor CK2, a voltage-dividing resistor RK1 and a voltage-dividing resistor RK3 and a grounding capacitor CK5;

[0011] +3.3V voltage is grounded through filter capacitor CK1, one end of magnetic bead LK1 is connected to filter capacitor CK1, and the other end outputs +3.3VA1 voltage and is grounded through voltage stabilizing capacitor CK2;

[0012] The other end of the magnetic bead LK1 is connected in series with the voltage divider resistor RK1 and the voltage divider resistor RK3 and then grounded. The voltage divider resistor RK1, the voltage divider resistor RK3 and the grounding capacitor CK5 are all connected as +1.65V1 to output to the voltage regulating resistor RI7.

[0013] Preferably, there are multiple resistor voltage divider circuits, and each resistor voltage divider circuit corresponds to N, A, B, and C of the ATS upper port voltage respectively.

[0014] Beneficial effects:

[0015] In order to reduce costs and ensure the accuracy of sampling, this application uses resistors for voltage division and is equipped with a power supply voltage stabilization circuit to assist the microcontroller in sampling. The high-voltage sampling resistor is connected to the microcontroller ADC port, and the real-time voltage value is calculated through a differential algorithm inside the microcontroller. Generally, the selection of resistors needs to consider the actual test withstand voltage and the voltage that can be recognized by the microcontroller ADC port.

[0016] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiment of the utility model with the accompanying drawings. The specific implementation method of the utility model is given in detail by the following embodiments and their drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0018] Figure 1 It is a resistance voltage division circuit diagram of the sampling voltage division constant voltage protection circuit of the utility model;

[0019] Figure 2 The utility model is a power supply voltage stabilizing circuit diagram of a sampling voltage-dividing constant voltage protection circuit. DETAILED DESCRIPTION

[0020] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become clearer according to the following description and claims. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0021] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0023] In order to reduce the cost brought by the operational amplifiers mostly used in traditional high-voltage voltage divider circuits and ensure the sampling accuracy, resistors are used for voltage division, and a voltage stabilization circuit is used to assist the microcontroller in sampling. The high-voltage sampling resistor is connected to the ADC port of the microcontroller, and the real-time voltage value is calculated by the differential algorithm inside the microcontroller. Generally, the selection of resistors needs to consider the actual test withstand voltage and the voltage that can be recognized by the ADC port of the microcontroller.

[0024] like Figure 1As shown, the embodiment of the utility model provides a sampling voltage-dividing constant voltage protection circuit, including: a resistor voltage-dividing circuit, the resistor voltage-dividing circuit includes a Schottky diode DI1, a voltage-dividing unit, a grounding capacitor C1 and a voltage-regulating resistor RI7, the Schottky diode DI1, the voltage-dividing unit, the grounding capacitor C1 and the voltage-regulating resistor RI7 are all connected to the ADC pin SIC_IN of the single-chip microcomputer; the input end of the voltage-dividing unit is connected to the ATS upper port voltage, one end of the voltage-regulating resistor RI7 is connected to the +1.65V1 voltage, and one end of the Schottky diode DI1 is connected to the +3.3VA1 voltage. The use of this protection circuit structure eliminates complex electronic components such as operational amplifiers, which not only simplifies the circuit design, but also reduces costs. And it can also ensure sampling accuracy, effectively realizing low-cost voltage acquisition of the ATS upper port voltage and being recognized by the ADC port of the single-chip microcomputer.

[0025] In a specific scenario, the ATS includes N, A, B, and C of the main upper port and the backup upper port. Each channel needs to be equipped with a separate sampling voltage-dividing constant voltage protection circuit. Therefore, this embodiment only explains one of the C terminals, and the same applies to other channels. The signal coming out of the C terminal is divided by the resistor voltage-dividing circuit to ensure that the output voltage can be recognized by the single-chip microcomputer. Then it is connected to the ADC pin of the single-chip microcomputer, and the final judgment voltage is displayed after internal conversion. A resistor voltage-dividing circuit consists of 6 series-connected high-voltage voltage-dividing resistors RI1~RI6, a grounding capacitor C1, a voltage-regulating resistor RI7, and a Schottky diode DI1. Taking phase C as an example, one end of the high-voltage voltage-dividing resistor RI1 is connected to the C-phase pin S1_C as the input end, and the voltage-regulating resistor RI7 is connected to the 1.65V1 power supply, and the high-voltage voltage-dividing resistor RI6, capacitor C1, and voltage-regulating resistor RI7 are all connected to one end of the Schottky diode DI1, and the other end of the Schottky diode DI1 is connected to the +3.3VA1 power supply. The capacitor CI1 to ground is a filter capacitor. Schottky diode DI1 is set to protect the microcontroller pin, limiting the voltage at this point to between 0 and 3.3V to ensure that the microcontroller will not be damaged when the voltage fluctuates.

[0026] The preferred solution is Figure 2As shown, because the voltage at the ATS port is AC, but the single-chip microcomputer can only collect voltages between 0 and 3.3, it is necessary to raise the voltage after high-voltage division to 1 / 2 of 3.3V and stabilize the voltage, so as to ensure that the voltage collected by the single-chip microcomputer is complete. The power supply voltage stabilization circuit includes filter capacitor CK1, magnetic bead LK1, voltage stabilizing capacitor CK2, voltage divider resistor RK1 and voltage divider resistor RK3 and grounding capacitor CK5. The +3.3V voltage is grounded through the filter capacitor CK1, one end of the magnetic bead LK1 is connected to the filter capacitor CK1, and the other end outputs a +3.3VA1 voltage and is grounded through the voltage stabilizing capacitor CK2. The other end of the magnetic bead LK1 is connected in series with the voltage divider resistor RK1 and the voltage divider resistor RK3 in turn and then grounded, and the voltage divider resistor RK1, the voltage divider resistor RK3 and the grounding capacitor CK5 are all connected as +1.65V1 output to the voltage regulating resistor RI7.

[0027] To facilitate understanding of the above scheme, an example is given to illustrate the above scheme. Among them, the voltage divider resistor of each phase is composed of 7 resistors, such as the output pin S1_C of the C phase in the three-phase (the other N, A and B are connected in a similar way to the C phase), RI1~RI6 are high-voltage voltage divider resistors, RI7 is used to adjust the voltage of the ADC sampling pin, because the microcontroller cannot recognize negative voltage, so the reference voltage needs to be raised to a positive voltage after the AC is divided by the resistor. Therefore, after the current end resistance is basically determined, the voltage of the microcontroller pin can be adjusted through RI7, and the S1C_IN pin is the ADC pin of the microcontroller. Because a certain overvoltage range needs to be considered when designing ATS, when adjusting the resistance value of RI7, it is necessary to ensure that the voltage division on RI7 does not exceed the lift-off voltage under overvoltage conditions, that is, ≤1.65V, and leave a certain margin; the selection of the resistance value and number of RI1~RI6 needs to refer to the level of EMC tests, such as surge, impact test, creepage distance, electrical clearance, etc. The number of resistors is determined according to the level of the test. The resistance value (R11~R16) selected here is 1MΩ, and the voltage at the sampling point is calculated as:

[0028] 230*120% / (6M+R)*R=1.03V, this value does not exceed 3.3-1.65=1.65V, that is, the higher the better within 1.65V. Here R is the resistance value of R17, R≤22.5KΩ. Figure 2 The 1.65V1 is obtained by dividing the +3.3V voltage by the power supply voltage regulator circuit, thereby providing a 1.65V voltage bias for the voltage regulating resistor RI7 in the resistor voltage divider circuit.

[0029] Other phases also have their own independent but structurally identical voltage-dividing and voltage-stabilizing circuits and power-supply voltage-stabilizing circuits, which ensure that their respective bias voltages do not interfere with each other. First, filter capacitor CK1 is used in the power-supply voltage-stabilizing circuit to filter the 3.3V voltage from the DC / DC by CK1, and then the interference is filtered by magnetic beads LK1, which can filter out most high-frequency interference and reduce 3.3V fluctuations. After the interference is filtered by magnetic beads LK1, the voltage-stabilizing capacitor CK2 is used to stabilize the voltage, and then the voltage is equalized using the circuit diagram above to ensure the stability of the 1.65V voltage.

[0030] This solution utilizes the Gaia voltage-divider microcontroller sampling circuit composed of resistors, capacitors and Schottky diodes, and the bias voltage-divider stabilizing circuit composed of resistors, capacitors and magnetic beads. Together with the ADC sampling of the microcontroller, it can sample and judge the AC power in real time. The sampling accuracy can be maintained at 3%. It can judge abnormal conditions such as loss of voltage, undervoltage, overvoltage, and phase failure at the upper port, and accurately issue conversion commands, greatly reducing the situation of no action or inaction caused by inaccurate sampling. This solution has a simple peripheral circuit, low cost, but strong reliability.

[0031] The above description is only a preferred embodiment of the utility model and does not impose any form of limitation on the utility model. Any ordinary technician in the industry can smoothly implement the utility model as shown in the drawings of the specification and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the utility model using the technical content disclosed above are all equivalent embodiments of the utility model. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the utility model are still within the protection scope of the technical solution of the utility model.

Claims

1. A sampling voltage-dividing constant voltage protection circuit, characterized in that: include: A resistor voltage divider circuit, wherein the resistor voltage divider circuit comprises a Schottky diode DI1, a voltage divider unit, a grounding capacitor C1 and a voltage regulating resistor RI7, wherein the Schottky diode DI1, the voltage divider unit, the grounding capacitor C1 and the voltage regulating resistor RI7 are all connected to the ADC pin SIC_IN of the single-chip microcomputer; The input end of the voltage dividing unit is connected to the ATS upper port voltage, one end of the voltage regulating resistor RI7 is connected to the +1.65V1 voltage, and one end of the Schottky diode DI1 is connected to the +3.3VA1 voltage.

2. The sampling voltage-dividing constant voltage protection circuit according to claim 1, characterized in that: The voltage dividing unit includes 6 high-voltage voltage dividing resistors connected in series.

3. The sampling voltage-dividing constant voltage protection circuit according to claim 2, characterized in that: The resistance value of each high-voltage voltage-dividing resistor is 1 MΩ.

4. The sampling voltage-dividing constant voltage protection circuit according to claim 1, characterized in that: The resistance of the voltage regulating resistor RI7 does not exceed 22.5KΩ.

5. The sampling voltage-dividing constant voltage protection circuit according to claim 1, characterized in that: The sampling voltage-dividing constant voltage protection circuit also includes a power supply voltage stabilizing circuit, which includes a filter capacitor CK1, a magnetic bead LK1, a voltage stabilizing capacitor CK2, a voltage-dividing resistor RK1 and a voltage-dividing resistor RK3 and a grounding capacitor CK5; +3.3V voltage is grounded through filter capacitor CK1, one end of magnetic bead LK1 is connected to filter capacitor CK1, and the other end outputs +3.3VA1 voltage and is grounded through voltage stabilizing capacitor CK2; The other end of the magnetic bead LK1 is connected in series with the voltage divider resistor RK1 and the voltage divider resistor RK3 and then grounded. The voltage divider resistor RK1, the voltage divider resistor RK3 and the grounding capacitor CK5 are all connected as +1.65V1 to output to the voltage regulating resistor RI7.

6. The sampling voltage-dividing constant voltage protection circuit according to claim 1, characterized in that: There are multiple resistor voltage divider circuits, and each resistor voltage divider circuit corresponds to N, A, B, and C of the ATS upper port voltage.

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