阅读说明：本技术 用于无源二次回路检查表的宽电压范围自动换档电路 (Wide voltage range automatic gear shifting circuit for passive secondary loop checking meter ) 是由 曹磊 杨盛德 白福庆 于 2020-12-15 设计创作，主要内容包括：本发明公开了用于无源二次回路检查表的宽电压范围自动换档电路,包括电阻分压电路、档位切换驱动电路和模数转换电路,电阻分压电路的一侧与档位切换驱动电路电性连接,档位切换驱动电路的一侧与模数转换电路电性连接,电阻分压电路接收电压信号并产生各相应比例的电压值,施加到档位切换驱动电路的各个光电耦合器PhotoMos的场效应管侧,微控制器/数字信号处理器预选通一个最大档位,然后根据读取到的模数转换电路转换的结果计算出目标档位。本发明采用执行器为光电耦合器PhotoMOS,执行速度快,可靠性高,可以根据需要配置档位数量而不影响切换速度,从而扩展/减小电压的动态输入范围,采用软件方式实现自动换档,可以实现大动态范围的电压精确检测计算。(The invention discloses a wide-voltage-range automatic gear shifting circuit for a passive secondary loop check meter, which comprises a resistance voltage dividing circuit, a gear switching driving circuit and an analog-to-digital conversion circuit, wherein one side of the resistance voltage dividing circuit is electrically connected with the gear switching driving circuit, one side of the gear switching driving circuit is electrically connected with the analog-to-digital conversion circuit, the resistance voltage dividing circuit receives a voltage signal and generates voltage values of corresponding proportions, the voltage values are applied to the field effect tube side of each photoelectric coupler PhotoMos of the gear switching driving circuit, a microcontroller/digital signal processor preselects a maximum gear, and then a target gear is calculated according to the read conversion result of the analog-to-digital conversion circuit. The invention adopts the photoelectric coupler PhotoMOS as the actuator, has high execution speed and high reliability, can configure the number of gears according to the requirement without influencing the switching speed, thereby expanding/reducing the dynamic input range of the voltage, realizes automatic gear shifting by adopting a software mode, and can realize the accurate detection and calculation of the voltage with large dynamic range.)

1. The wide-voltage-range automatic gear shifting circuit for the passive secondary circuit checking meter comprises a resistance voltage division circuit (1), a gear switching driving circuit (2) and an analog-to-digital conversion circuit (3), wherein one side of the resistance voltage division circuit (1) is electrically connected with the gear switching driving circuit (2), and one side of the gear switching driving circuit (2) is electrically connected with the analog-to-digital conversion circuit (3).

2. The wide voltage range automatic shift circuit for a passive secondary loop checklist of claim 1, further comprising the steps of:

s1: the resistance voltage dividing circuit (1) receives a voltage signal and generates voltage values of corresponding proportions, the voltage values are applied to the field effect tube side of each photoelectric coupler PhotoMos of the gear switching drive circuit (2), the microcontroller/digital signal processor (202) preselects a maximum gear, then a target gear is calculated according to a read conversion result of the analog-to-digital conversion circuit (3), and a corresponding gear is selected;

s2: the gear switching circuit (2) can be divided into a gear switching drive (201) and a microcontroller/digital signal processor (202), wherein UDA 0-UDAN are respectively connected with signals of voltage dividing resistors of phase A, the value of N depends on the number of gears, and the microcontroller/digital signal processor (202) is used for providing control signals for gear switching;

s3: an analog-to-digital conversion circuit chip of the analog-to-digital conversion circuit (3) can provide 6 pseudo differential signal inputs and can synchronously sample, and data is transmitted to the microcontroller/digital signal processor (202) through the SPI bus to be operated.

3. The wide voltage range automatic shift circuit for a passive secondary loop checklist of claim 2, wherein the resistor divider circuit (1) receives an alternating voltage signal and produces a corresponding proportional voltage at each resistor.

Technical Field

The invention relates to the technical field of electrical measurement, in particular to a wide-voltage-range automatic gear shifting circuit for a passive secondary circuit checking meter.

Background

In an electrical measurement system, a voltage transformer is adopted in traditional voltage detection, primary or secondary taps are switched according to the amplitude of an input signal so as to adapt to the optimal input range of an analog-to-digital converter (ADC) in the system, the voltage transformer is large in size and small in dynamic input range and changes greatly along with the ambient temperature, a technical scheme that a plurality of precise resistors are adopted for voltage division is adopted along with the development of the technology, and an analog switch or a relay is adopted for switching signals close to the input fullness of the ADC according to the change range of the input signal, but the input voltage range of the analog switch is narrow, so that the dynamic input range is small, and the relay occupies a larger space.

Therefore, the above two schemes have the disadvantages of small dynamic range input or large volume, and slow speed of gear switching of the relay.

Disclosure of Invention

It is an object of the present invention to provide a wide voltage range automatic shift circuit for a passive secondary loop look-up table to solve the problems set forth in the background above.

In order to achieve the purpose, the invention provides the following technical scheme: the wide-voltage-range automatic gear shifting circuit for the passive secondary circuit checking meter comprises a resistance voltage division circuit, a gear switching driving circuit and an analog-to-digital conversion circuit, wherein one side of the resistance voltage division circuit is electrically connected with the gear switching driving circuit, and one side of the gear switching driving circuit is electrically connected with the analog-to-digital conversion circuit.

Preferably, the specific operation steps are as follows:

s1: the resistance voltage dividing circuit receives the voltage signal and generates voltage values of corresponding proportions, the voltage values are applied to the field effect tube side of each photoelectric coupler PhotoMos of the gear switching driving circuit, the microcontroller/digital signal processor preselects a maximum gear, then a target gear is calculated according to a read conversion result of the analog-to-digital conversion circuit, and the corresponding gear is selected;

s2: the gear switching circuit can be divided into a gear switching drive part and a microcontroller/digital signal processor part, wherein UDA-UDAN are respectively connected with signals of A-phase divider resistors, the value of N depends on the number of gears, and the microcontroller/digital signal processor is used for providing control signals for gear switching;

s3: the analog-digital conversion circuit chip of the analog-digital conversion circuit can provide 6 paths of pseudo-differential signal input and can synchronously sample, and data is transmitted to the microcontroller/digital signal processor through the SPI bus to be subjected to operation processing.

Preferably, the resistor voltage dividing circuit receives an alternating voltage signal and generates voltages with corresponding proportions at the resistors.

The invention has the technical effects and advantages that:

(1) the resistance voltage dividing circuit converts the input voltage signals into N groups of voltage signals according to the voltage input range and the gear number N, ensures that the rated voltage of each gear voltage is close to the full range of the analog-digital converter analog-digital conversion circuit, the analog-digital conversion circuit converts the input analog voltage signals into digital signals, the converted value is transmitted to a microcontroller/digital signal processor, a gear shift control and drive circuit consists of the microcontroller/digital signal processor and an MOS output photoelectric coupler PhotoMOS, the microcontroller/digital signal processor analyzes according to the data transmitted by the analog-to-digital conversion circuit, if the full scale value is reached, the PhotoMOS is directly driven to the maximum gear, the proper gear is judged to be switched again according to the data of the analog-digital conversion circuit read when the maximum gear is reached, and driving PhotoMOS to switch, the three-phase four-wire three-phase three-wire mode switching circuit is used for switching to a suitable tested object;

(2) the actuator is a photo MOS (photo-electric coupler), the execution speed is high, the reliability is high, the number of gears can be configured according to needs without influencing the switching speed, so that the dynamic input range of voltage is expanded/reduced, automatic gear shifting is realized by adopting a software mode, and the accurate voltage detection and calculation in a large dynamic range can be realized.

Drawings

FIG. 1 is a block diagram of an embodiment of a wide voltage range automatic shift detection circuit according to the present invention.

Fig. 2 is a circuit diagram of the resistor divider circuit according to the present invention.

FIG. 3 is a circuit diagram of the shift control drive circuit of the present invention.

Fig. 4 is a circuit diagram of an analog-to-digital conversion circuit of the present invention.

In the figure: 1. a resistance voltage-dividing circuit; 2. a gear switching drive circuit; 201. gear switching drive; 202. a microcontroller/digital signal processor; 3. an analog-to-digital conversion circuit.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The present invention provides a wide voltage range automatic shift circuit for a passive secondary loop look-up table as shown in figures 1-4,

example (b):

the gear shifting circuit comprises a resistance voltage division circuit 1, a gear shifting driving circuit 2 and an analog-to-digital conversion circuit 3, wherein one side of the resistance voltage division circuit 1 is electrically connected with the gear shifting driving circuit 2, and one side of the gear shifting driving circuit 2 is electrically connected with the analog-to-digital conversion circuit 3;

the resistance voltage division circuit 1 receives the voltage signal and generates voltage values of corresponding proportions, the voltage values are applied to the field effect tube side of each photoelectric coupler PhotoMos of the gear switching drive circuit 2, the microcontroller/digital signal processor 202 preselects a maximum gear, then a target gear is calculated according to the read conversion result of the analog-to-digital conversion circuit 3, and the corresponding gear is gated;

the resistor divider circuit 1 receives the alternating voltage signal, generates voltages with corresponding proportions on each resistor, for example, the voltage divided on the resistor R100 is the voltage divided on the resistor R101, and so on, the voltage generated on the xth resistor is the voltage, and here, the number of the divider resistors and the corresponding resistance value need to be determined according to the input range and the dynamic technical index of the selected analog-to-digital conversion circuit 3;

the gear switching circuit 2 can be divided into a gear switching driver 201 and a microcontroller/digital signal processor 202, wherein UDA 0-UDAN are respectively connected with signals of voltage dividing resistors of phase A, the value of N depends on the number of gears, and the microcontroller/digital signal processor 202 is used for providing control signals for gear switching;

the analog-to-digital conversion circuit chip of the analog-to-digital conversion circuit 3 can provide 6 pseudo-differential signal inputs, and can synchronously sample, and data is transmitted to the microcontroller/digital signal processor 202 through the SPI bus to be processed.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.