A kind of portable intelligent signal generation calibration equipment
Technical field
The utility model relates to a kind of device that is used for the verification commercial unit, especially a kind of portable intelligent signal generation calibration equipment that is applicable to direct current measurement equipment.
Background technology
The calibration equipment of present direct current measurement equipment both domestic and external can satisfy the verification demand of the high precision measuring device of different DC voltages and current class basically.Simultaneously, to the verification of intelligent industrial instrument, a lot of similarly portable intelligent signal generation calibration equipments have also been released; And powerful, it can measure and export the voltage signal of mV level, V level, the current signal of mA level; Even can also export the signal of using always in the multiple industrial measurement and control processes such as frequency signal of Hz level, kHz level; Can select the supplied by AC/DC electricity mode easily for use, in the production and measurement that are applicable to factory, in addition; Also can select the calibration equipment of supplying power for use, to be applicable to the situation of being inconvenient to provide external power source from charged pool.
, the calibration equipment of existing direct current measurement equipment is because the requirement of function and aspect of performance is tens of kilograms the weight and the price of tens thousand of units basically, and this is very improper for the equipment that simple application is only arranged (for example centralized automatic meter-reading terminal).And at common on the market portable intelligent signal generation calibration equipment; Though from function aspects, it has satisfied the verification requirement of simple application equipment such as centralized automatic meter-reading terminal basically, from price; Still obviously higher, basically all more than thousands of units.In addition; Dc voltage and current is set inconvenient, mostly can't realize setting through the mode of PC host computer, and not carry high-precision dc voltage and current acquisition function; Simultaneously; On the checking table of existing centralized automatic meter-reading terminal, available space is less, and existing general calibration equipment commonly used is inconvenient to install or put.
The utility model content
In order to address the above problem, the purpose of the utility model provides a kind of simple in structure, the portable intelligent signal generation calibration equipment that cost is low.
The technical scheme that the utility model adopts is: a kind of portable intelligent signal generation calibration equipment; It is characterized in that: this device comprises checking circuit; Said checking circuit comprises ac power supply circuit and governor circuit; Said governor circuit is connected with communication interface circuit, dc voltage and current Acquisition Circuit and dc voltage and current output circuit respectively, and said ac power supply circuit is respectively governor circuit, communication interface circuit, dc voltage and current Acquisition Circuit and the power supply of dc voltage and current output circuit.
Further, this device also comprises structural member, and said structural member is made up of shell and terminal row, and said checking circuit is installed in the enclosure.
Further, said governor circuit is provided with the synchronous serial Peripheral Interface, and is connected with dc voltage and current Acquisition Circuit and dc voltage and current output circuit respectively through the synchronous serial Peripheral Interface.
Further, said communication interface circuit is the RS485 communication interface circuit.
Further, said governor circuit by Cortex M0 processor with and peripheral circuit form; Said dc voltage and current Acquisition Circuit is made up of modulus conversion chip AD7793 and peripheral circuit thereof; Said dc voltage and current output circuit is made up of analog-digital chip AD5422 and peripheral circuit thereof.
The beneficial effect of the utility model is: the utility model is simple in structure, handled easily, and cost is low, and because the utility model is provided with communication interface circuit, therefore, it can be communicated by letter with host computer, conveniently carries out each item and sets and verification.
In addition, because through the use Industrial Frequency Transformer, so on electric, be to isolate each other between each circuit, thereby prevent in checking procedure, because causing relevant device, accident damages.And dc voltage and current Acquisition Circuit and dc voltage and current output circuit all adopt high-precision chip, can improve the precision of image data and the stability of verification.
Description of drawings
Be described further below in conjunction with the embodiment of accompanying drawing the utility model:
Fig. 1 is the structured flowchart of the utility model.
Embodiment
Can know by Fig. 1; A kind of portable intelligent signal generation calibration equipment; This device comprises checking circuit; Said checking circuit comprises ac power supply circuit and governor circuit, and said governor circuit is connected with communication interface circuit, dc voltage and current Acquisition Circuit and dc voltage and current output circuit respectively, and said ac power supply circuit is respectively governor circuit, communication interface circuit, dc voltage and current Acquisition Circuit and the power supply of dc voltage and current output circuit.
Said ac power supply circuit is used to calibration equipment power supply is provided, it by an Industrial Frequency Transformer that is no less than 4W with and peripheral circuit form.The specified alternating voltage of said Industrial Frequency Transformer input is 220V; The specified alternating current of input is 200mA; And said Industrial Frequency Transformer is exported several kinds of different power supplys: first kind, the AC power of output is 8V/100mA, behind the 5V DC voltage, offers governor circuit through rectifying and voltage-stabilizing then; Second kind, the AC power of output is 8V/30mA, behind the 5V DC voltage, offers communication interface circuit through rectifying and voltage-stabilizing; The third; The power supply of output is two 15V alternating voltages; Then through offering the dc voltage and current output circuit behind the rectifying and voltage-stabilizing one-tenth ± 12V DC voltage, wherein+the 12V DC voltage passes through voltage stabilizing once more, and voltage stabilizing offers the dc voltage and current Acquisition Circuit after becoming the 5V DC voltage; Said pair of 15V alternating voltage winding wants positive supply winding output current to be not less than 80mA, and negative supply winding output current is not less than 50mA.For guaranteeing the good performance of calibration equipment, require the withstand voltage 2000V of the being not less than alternating voltage between each secondary winding (output winding), and the withstand voltage 4000V alternating voltage that is not less than between the input and output.
Said governor circuit, mainly by one cheaply Cortex M0 processor with and basic peripheral circuit form.Said processor is being provided with 1 road UART interface, 1 road SPI interface at least, can using the I/O mouth, the in-chip FLASH that RAM that 4K is above and 16K are above more than 5 on the peripheral hardware.Said governor circuit is in core position in whole device.
Said communication interface circuit, said communication interface circuit are the RS485 communication interface circuits, and it mainly realizes the communication bridge function between governor circuit and host computer, this circuit comprise 1 the tunnel with the RS485 circuit of governor circuit light-coupled isolation.
Said dc voltage and current Acquisition Circuit; It is made up of 4 modulus conversion chip AD7793 of 1 high-precision two-channel 2-4 and peripheral circuit thereof; The SPI interface of this chip through isolating under the control of governor circuit, is accomplished the 0-5V DC voltage neatly; The high precision collecting of 0-20mA DC current makes things convenient for the verification at direct current measurement equipment (for example centralized automatic meter-reading terminal).
Said dc voltage and current output circuit, it is made up of 1 high-precision 16 figure place mould conversion chip AD5422 and peripheral circuit thereof.The SPI interface of this chip through isolating under the control of governor circuit, is exported the 0-5V DC voltage of setting, 0-20mA DC current neatly.
Further as preferred embodiment, this device also comprises structural member, and said structural member is made up of shell and terminal row, and said checking circuit is installed in the enclosure.Said structural member adopts the plastic casing and the terminal row of the single-phase electric energy meter of present standard universal; Such structural member not only can conveniently be installed said checking circuit, can also easily the utility model be installed on the checking table; And make full use of existing mould, thereby reduce cost.
Further as preferred embodiment, said SPI interface is the synchronous serial Peripheral Interface, and said governor circuit is connected with dc voltage and current Acquisition Circuit and dc voltage and current output circuit respectively through the SPI interface.The processor of governor circuit can communicate with the dc voltage and current output circuit with the dc voltage and current Acquisition Circuit respectively through same SPI interface on peripheral hardware and be connected; Also can be through being respectively equipped with and dc voltage and current Acquisition Circuit and the corresponding SPI interface of dc voltage and current output circuit, and then communicate connection.
More than be that preferable enforcement to the utility model specifies; But the utility model is created and is not limited to said embodiment; Those of ordinary skill in the art make all equivalent variations or replacement under the prerequisite of the utility model spirit, also can doing, and distortion that these are equal to or replacement all are included in the application's claim institute restricted portion.