CN2442278Y

CN2442278Y - Voltage current power detector

Info

Publication number: CN2442278Y
Application number: CN 00239384
Authority: CN
Inventors: 周伶
Original assignee: Electrotechnical Branch Of Qingtian Industry Co Ltd Guangzhou
Current assignee: Electrotechnical Branch Of Qingtian Industry Co Ltd Guangzhou
Priority date: 2000-09-07
Filing date: 2000-09-07
Publication date: 2001-08-08
Anticipated expiration: 2010-09-07

Abstract

The utility model relates to a voltage-current-power tester, which is used for monitoring the electrical parameters of household appliances and electric apparatus with similar usage, and is composed of a single-chip microcomputer system, a display interface circuit, a keyboard interface circuit, a communicating interface circuit, a data test changeover circuit, an automatic timing control circuit, an automatic range switching circuit, a pattern dot matrix liquid crystal module, a keyboard input circuit, a test software, etc. The tester of the utility model adopts a large-screen liquid crystal display and the complete Chinese display of a test main menu and a setting submenu, and can carry out the automatic timing of tested data to realize RS232 multi-machine communication. The utility model has the advantages of reliable operation, high testing precision, convenient operation and low cost performance ratio, and is suitable for unit set use or detecting automatic assembly line through coming out of factory.

Description

The electric current and voltage power measuring

The utility model relates to a kind of household electrical appliance and similar applications electrical equipment electrical quantity (voltage, electric current, active power, power factor) test instrumentation, belongs to electrical instrument measurement mechanism technical field.

It is reported that the instrument kind of test electrical voltage, electric current, power, power factor is a lot of at present both at home and abroad, this type of instrument that domestic and international leading firm is produced, almost adopt charactron to show entirely, when instrument function more for a long time, panel button is various, complicated operation, not directly perceived.And existing most of instrument design is that separate unit uses, and point-to-point RS232 communication only is provided, but the RS232 serial line interface of easy multi computer communication can not directly be provided, and this makes troubles for closely simple multi computer communication.

The utility model purpose is to overcome above-mentioned shortcoming, provides a kind of function stronger, and intuitive display is easy to operate, RS232 serial ports multi computer communication, adjustment automatically, intelligent voltage, electric current, power, power factor tester that accuracy is high.

The purpose of this utility model is to realize like this.By instrument chassis, have the instrument face plate and the back plate of input-output unit, be fixed on the single-chip microcomputer plate (S-33) in the instrument chassis, become and send plate (S-34), transformer board (S-31) is vertically mounted on the display key plate compositions such as (S-32) behind the instrument face plate.Plate is equipped with supply socket after the instrument, calibrating terminal, RS232 serial line interface socket.The single-chip microcomputer plate is equipped with the A/D change-over circuit, Single Chip Microcomputer (SCM) system, keyboard interface circuit, display interface circuit, communication interface circuit.Communication interface circuit on the single-chip microcomputer plate is equipped with photoelectric isolating circuit, special-purpose level transferring chip and diode VD3.The change of tester send plate that voltage transformer (VT) is housed, current transformer, programmable amplifier, electric current and voltage power test circuit, adjustment control circuit automatically.The display key plate is equipped with keyboard interface circuit, display interface circuit, 240 * 64 graphic dot matrix Liquid Crystal Modules and 6 operation push-buttons.Transformer board is equipped with power transformer and electric source filter circuit, is the single-chip microcomputer plate, becomes to send plate and display key plate that power supply is provided.During test, model machine links to each other with the calibrating terminal of back on the plate, and tested voltage and electric current send voltage, current transformer isolated variable on the plate by change, export programmable amplifier and electric current and voltage power test circuit to through multi-way switch.Automatic aiming boss circuit adopts temperature to float the low precision voltage regulator of coefficient and wire-wound resistor is made reference source, is connected to the input of multi-way switch.The output of electric current and voltage power test circuit is connected to the A/D change-over circuit on the single-chip microcomputer plate.Digital signal after the A/D change-over circuit will be changed sends Single Chip Microcomputer (SCM) system to, and Single Chip Microcomputer (SCM) system is made up of single-chip microcomputer and peripheral interface circuit thereof.Single-chip microcomputer reads and handles the A/D output signal, will test master menu by display interface circuit and be presented on the LCDs.Single-chip microcomputer is judged the size of electric current, by automatic range control signal controlling programmable amplifier, carries out corresponding range and switches.The automatic adjustment signal of single-chip microcomputer timed sending is realized automatic adjusting function to multi-way switch.During adjustment, multi-way switch is connected automatic aiming boss circuit and test circuit, and during test, multi-way switch is connected voltage current transformer output and test circuit.Communication interface circuit on the single-chip microcomputer plate links to each other with the RS232 serial line interface socket of back on the plate, and the RS232 communication port of standard is provided, can be directly and host computer carry out the data transmission.Various parameters (warning limit value, system's setting, communications parameter etc.) required in the instrument use can be provided with by keyboard operation.The instrument keyboard links to each other with Single Chip Microcomputer (SCM) system through keyboard interface circuit.When being provided with, show submenu respectively to be set and cursor is set.

The utlity model has following advantage:

1, adopted the core of the AT89C55 single-chip microcomputer of band flash memory, be equipped with band Programmable Watchdog E EPROM functional chip again, simplified instrument structure, strengthened the antijamming capability of instrument as instrument.2, adopt MAX202 level transferring chip and diode VD3, eliminate the influence of multi-disc MAX202 parallel connection, satisfy the requirement of multi computer communication its output terminal level.3, adopt big screen LCD, Chinesizing menu, intuitive display.4, adopt keyboard to carry out feature operation and parameter setting, on liquid crystal display, show various status informations and parameter setting information simultaneously.5, each parameter classification is provided with, and differentiated control simplifies the operation.6, can set electric current and voltage power upper and lower limit alarming value.6, range can be changed automatically.7, instrument adjustment automatically.8, to the important parameter password locking.9, have self-checking function, can judge whether transmission circuit or single chip circuit have fault, be convenient to debugging and maintenance.

Fig. 1 is structural representation of the present utility model (vertical view).

Fig. 2 is a principle of work block diagram of the present utility model.

Fig. 3 is a transmission circuit schematic diagram of the present utility model.

Fig. 4 is a single chip circuit schematic diagram of the present utility model.

Fig. 5 is a communicating circuit schematic diagram of the present utility model.

Fig. 6 is display keyboard circuit theory diagrams of the present utility model.

Fig. 7 is a panel layout of the present utility model.

Fig. 8 is a back of the present utility model plate arrangenent diagram.

Fig. 9 is that test master menu of the present utility model shows synoptic diagram.

Figure 10 is that warning limit value setup menu of the present utility model shows synoptic diagram.

Below in conjunction with accompanying drawing preferred embodiment of the present utility model is described.

With reference to Fig. 1, instrument adopts 320 * 330 * 100 (mm) standard PC case.Wherein to send plate, S-33 be the single-chip microcomputer plate to S-34 in order to become, and S-31 is a transformer board, and S-32 is the display key plate.LCD MODULE and 6 input button is fixed on the S-32 plate and attached to behind the film face-plate.On the back plate supply socket is housed, calibrating terminal and RS232 serial line interface socket.Various interface on the plate of on each wiring board and back is connected by lead.Among Fig. 2, the supply voltage of tested model machine (D2, D3 input) send the conversion of the voltage transformer (VT) summation current transformer on the plate with load current (D1, D5 input) through change, switch respectively and circuit for testing voltage with multi-way switch through automatic adjustment control again, power test circuit and programmable amplifier link to each other, and the output of programmable amplifier is as the input of electric current and power test circuit.Automatically during adjustment, multi-way switch is connected automatic aiming boss circuit and circuit for testing voltage and programmable amplifier; During test, multi-way switch is connected mutual inductor output and circuit for testing voltage and programmable amplifier.By the automatic range control signal controlling programmable amplifier that single-chip microcomputer sends, make it when the high and low shift range, have different enlargement factors, satisfy the test accuracy requirement.Voltage, electric current, the output of power test circuit are connected to the A/D converter circuit input end respectively, and the output of A/D change-over circuit links to each other with single-chip microcomputer, Single Chip Microcomputer (SCM) system timing acquiring A/D translation data go forward side by side line data processing and data presentation.The RS232 serial communication signals links to each other with single-chip microcomputer by the communication interface circuit, and LCD MODULE links to each other with single-chip microcomputer by display interface circuit, and keyboard signal links to each other with single-chip microcomputer by keyboard interface circuit.Among Fig. 3; voltage and current signal is connected to multi-way switch IC1 (4052) input X3, Y3 through voltage transformer (VT) TV and current transformer TA; be connected to X1, Y1, X2, the Y2 of IC1 respectively by accurate stabilivolt VD1 (LM336) and R16～automatic aiming boss circuit that R19 precision wire-wound resistor dividing potential drop is formed, ground voltage is connected to X0, the Y0 of IC1.MB, MA are automatic adjustment control signal.During automatic zero set (AZS), X0, Y0 and IC1 output X, Y connect, and when calibrating automatically, X1, Y1 or X2, Y2 and IC1 output X, Y connect, and X3, Y3 and IC1 output X, Y connect during test.IC1 output X is connected to programmable amplifier.Programmable amplifier is made up of operational amplifier IC2 (0P07), analog switch IC3 (4051) and resistance R 3～R7.Programmable amplifier is exported an end and is connected to rms value converter IC4 (AD536) by R8, forms current testing circuit, and the other end is connected to the current input terminal 18 of power chip IC6 (VI-2) after resistance R 9, R10 dividing potential drop.Electric current programmable amplifier when high and low shift has different enlargement factors, and MLC is the range control end.IC1 output Y one end links to each other with rms value converter IC5 (AD536) by R13, forms circuit for testing voltage, and the other end is connected to IC6 (VI-2) voltage input end 5 after R11, R12 dividing potential drop.V-IN, I-IN, P-IN are respectively voltage, electric current, power test circuit output end, link to each other with A/D on the single-chip microcomputer plate.Among Fig. 4, send I-IN, V-IN, the P-IN signal of plate output to be connected to 12 bits serial A/D conversion chip IC7 (TLC2543) input end by change, accurate stabilivolt VD2 (LM336) output is connected to IC7 Voltage Reference end VREF, and A/D output links to each other with single-chip microcomputer IC10 (AT89C55) every IC8 (TLP521-4) through light.By the single chip computer AT 89C55 that has the 20K flash memory (IC10), extend out data-carrier store 6264 (IC14), I/0 extended chip 8255 (IC15), X25045 chip IC 9 with 512 byte EEPROM Programmable Watchdog functions, the Single Chip Microcomputer (SCM) system that data latches 74LS373 (IC12) and code translator 74LS138 (IC13) are constituted is a core of the present utility model, it is the output data of circle collection A/D regularly, handle and show, according to the conversion of data processed result control range, regularly carry out the automatic adjustment of test result, and monitor keyboard state at any time, carry out function corresponding operation and parameter setting.IC11 (74LS00) and Single Chip Microcomputer (SCM) system part control signal are formed LCD interface, link to each other with LCD MODULE on the display key plate.The RXD of IC10, TXD end links to each other with communication interface, realizes corresponding communication level conversion.Fig. 5 is the communication interface circuit on the single-chip microcomputer plate, adopts IC17 (MAX202) to realize the conversion of Transistor-Transistor Logic level and 232 level, influences each other for avoiding instrument and computing machine, adopts light every IC16 (TLP521-4) between Single Chip Microcomputer (SCM) system and IC17.For realizing multi computer communication, at IC17 output terminal T1OUT series diode VD3, it can eliminate the influence of multi-disc MAX202 parallel connection to T1OUT end level, satisfies the requirement of multi computer communication.Every IC16 and single-chip microcomputer TXD, RXD's communicating circuit input end links to each other by light, and the output terminal lead-in wire is connected to the RS232 serial line interface on the plate after the instrument.Among Fig. 6, the display keyboard circuit is by 240 * 64 graphic dot matrix LCD MODULE and display interface circuits, and 6 are touched keyswitch SB0 (reset key), SB1 (key is set), SB2 (

Key), SB3 ( Key), SB4 (| key), SB5 (latching key) and keyboard interface circuit are formed, and display interface and keyboard interface link to each other with the corresponding interface on the single-chip microcomputer plate.Fig. 7 is the utility model panel layout, and the panel left side is the LCDs of a 128mm * 36mm (long * wide), shows test data, data is set, information such as instrument running status.2 row's 6 buttons (3 of every rows) are being arranged on panel the right, and be respectively key is set,

Key (increase key), Key (minimizing key), | key (key moves to right), latch key, reset key.Can realize the data setting, data latching, instrument function such as reset.The panel lower right is a power switch.Fig. 8 is a back plate arrangenent diagram, comprises supply socket, fuse holder, 9 cores, 232 standard interface sockets, D1～D5 output wiring terminal.Each link of the utility model testing process all is that thoughtful in an Analysis of Nested Design, powerful software commander finishes down.The instrument operation divides test and two processes is set, carry out system initialization after powering on, enter test process then, real-time monitor input terminal also shows test master menu (as Fig. 9) on LCDs, test master menu content comprises instrument operation indication (menu upper left side round dot), voltage, electric current, power, the power factor test data, defective indication is (after being instructed in each test data, U represents that this item number is defective according to the upper limit, L represents that this item number is defective according to lower limit), (the menu lower right comprises and latching the indication of Meter Test state, report to the police, the self check three state).Instrument adopts open user interface, can various parameters (systematic parameter, each test item bound alarming value, communications parameter, correction factor etc.) be set according to the test needs, by

Key,

Key, | key operation and screen cursor indication, carry out the parameter setting.Figure 10 is a warning limit value setup menu, and the cursor prompting user of glimmering on the display screen is provided with this parameter.When setting option more for a long time, for simplifying setting operation, each setting option is carried out differentiated control, progressive operation.Formulate the standard communications protocol during instrument design and offered user's use, made things convenient for the user to realize multi computer communication.

Claims

1, a kind of electric current and voltage power measuring that is used to test household electrical appliance and similar applications electrical equipment electrical quantity, it is by instrument chassis, the instrument face plate and the back plate that have input-output unit, plate is sent in the change that is fixed in the instrument chassis, the single-chip microcomputer plate, transformer board is fixed on the compositions such as display key plate behind the instrument face plate.It is characterized in that the single-chip microcomputer plate is equipped with the A/D change-over circuit, Single Chip Microcomputer (SCM) system, keyboard interface circuit, display interface circuit, the communication interface circuit, the output of electric current and voltage power test circuit is connected to A/D change-over circuit input end respectively, the output of A/D change-over circuit links to each other with single-chip microcomputer, keyboard interface circuit, display interface circuit, the output of communication interface circuit links to each other with the single-chip microcomputer input end respectively.

2, tester according to claim 1 is characterized in that the communication interface circuit on the single-chip microcomputer plate is equipped with photoelectric isolating circuit, special-purpose level transferring chip and diode VD3.Every IC16 and single-chip microcomputer TXD, RXD's communicating circuit input end links to each other by light, and the output terminal lead-in wire is connected to the RS232 serial line interface on the plate after the instrument.

3, according to claim 1,2 described testers, the change that it is characterized in that tester send plate that voltage transformer (VT) is housed, current transformer, programmable amplifier, electric current and voltage power test circuit, adjustment control circuit automatically, Automatic Range-changing Circuit, the mutual inductor input end links to each other with the calibrating terminal of back on the plate, and its output terminal links to each other with programmable amplifier and electric current and voltage power test circuit with multi-way switch through adjustment automatically, and is connected to the A/D change-over circuit on the single-chip microcomputer plate.Automatically adjustment control signal and range control signal are connected to single-chip microcomputer output.

4, according to claim 1,2,3 described testers, it is characterized in that the display key plate is equipped with keyboard interface circuit, display interface circuit, 240 * 64 graphic dot matrix Liquid Crystal Modules and 6 operation push-buttons, its keyboard interface circuit, display interface circuit are connected to the corresponding interface on the single-chip microcomputer plate respectively.