A kind of insulation resistance test system
The present invention relates to a kind of megger test technology, refer more particularly to a kind of multilayer board insulation resistance automatic checkout system.
Electrical safety is the basic demand of instrument operate as normal, when using printed board, need test the electric conductivity of printed board; Present existing method of testing is illustrated in figures 1 and 2, utilizes an insulation resistance meter and one group of programmed switch, each measured object is received insulation resistance meter respectively measure; But the shortcoming of above-mentioned measuring method has: 1, testing efficiency is low, because national standard requires in the megger test process, must apply 60 seconds DC voltage earlier; Just begin to measure leakage current, therefore, 1 measured object of every test; Just need 1 minute at least, and the test point of pcb board is often many, at least tens.Even hundreds of, so test the needs several hrs one time, and according to the requirement of PCB test, normally 30 minutes just must test once, therefore when number of test points few, testing efficiency will be serious low.2, the accuracy requirement of programmed switch is high, but because testing efficiency is low, and when more test point, existing equipment satisfies the requirement of test, so more equipment is tested, can cause testing cost high like this.
Publication number is the Chinese patent of CN101470145A; Disclose a kind of insulation resistance test system, having comprised: computing machine, be used to send the control module of test parameter and test command, be used for based on test parameter and test command from affiliated computing machine; Send voltage control signal and test control signal; And test loop, receive said voltage control signal and test control signal, will convert the high direct voltage signal from the dc low-voltage signal of power supply into according to said voltage control signal; And change the test macro range according to test control signal, measurement insulation resistance is also exported measurement result.This method of testing can accurately be measured the resistance of single insulating trip, but in the face of need measure a plurality of pcb board simultaneously the time, but being lower than 50V in the face of test voltage is lower than small voltage, insulation resistance is greater than 10
11During Ω, often be difficult to satisfy real Testing requirement.
Summary of the invention
Forbidden in order to overcome to measure when existing test system and test efficient is hanged down with little test voltage, the present invention provides a kind of testing efficiency high and high-precision insulation testing system, comprising:
Industrial PC, said industrial PC are used for test request and send program control instruction;
Said programme-controlled dc power sends test voltage according to test request;
Programme-controlled dc power, said programme-controlled dc power receives program control instruction, and sends test voltage by program control command request;
Ups power, said ups power are that test macro provides stable power;
Little reometer, said little reometer is used for testing the little electric current that flows through specimen;
Little rheotrope, said little rheotrope is used for the opening and closing in test macro loop;
Test macro control box, said test macro control box are the sending controling unit of program control instruction.
Optimized technical scheme of the present invention is, is provided with the operational system Control Software in the said industrial PC, and said operational system Control Software is handled and analyzed the data of test.
Optimized technical scheme is to be provided with instrumentation tap in the said test macro control box.
Optimized technical scheme is, said test macro also comprises the environmental testing case, and said environmental testing case is used to provide the test environment of specimen.
Optimized technical scheme is, said test macro also comprises external interface, and said external interface is arranged in the system, and can be connected with specimen.
Optimized technical scheme is, is provided with copper bar in the plug-in box of said external interface, and said copper bar is a test lead grounded shield copper bar, to be used to guaranteeing that shells of all test bayonet nut connectors (BNC) link to each other with screen layer, raising system interference free performance.
Optimized technical scheme is, said plug-in box is articulated in the both sides of rack through the both sides bolt, to make things convenient for cabling, wiring.
Optimized technical scheme is, said programme-controlled dc power, little rheotrope, little reometer, specimen constitute some test loops, and said test loop is a TCH test channel.
Optimized technical scheme is that said test loop adopts positive and negative electrode to separate cabling.
Preferably, the circuit on the said test loop is provided with electromagnetic interference resistant device, earth magnetism countermeasure set.
Preferably, said specimen is a printed circuit board, and said printed circuit board is the positive source connection strap.
Preferably, said little rheotrope adopts a main control system, and 8 test integrated circuit boards insert pattern, and every integrated circuit board in said 8 test integrated circuit boards is controlled 16 passages, and industrial PC is opened through the instruction control passage, makes up every test loop.
Preferably, said ups power also is provided with system alarming device, and the acting as of said system alarming device when external world's power supply sudden power, preserved test data being used for, and prevents unexpected power down loss of data.
Technique effect of the present invention is:
1), improves testing efficiency: adopt the unified pressurization of dividing into groups; The mode of pointwise test leakage current effectively improves test speed, and test speed is the highest can to reach 1 point/1 second; In equivalent time, enlarge test point, a cover system max cap. of the present invention can reach 256 test points.
2), improve measuring accuracy: A, the present invention adopts positive and negative electrode to separate the cabling design for test loop, and adopts high insulation protection material, makes insulation characterisitic between the test loop considerably beyond the resistance of measured object, effectively reduces test error.B, the present invention adopt anti-electromagnetic interference (EMI), earth magnetism jamming countermeasure on the line, effectively reduce and disturb the extra interference electric current that is brought.C, the present invention can accomplish in test capacity to be 256 test point, add under the test voltage of 5V, guarantee that when 0.1T Ω measuring accuracy is less than 10%.
3), strengthen reliability:
The utilization industrial PC is as control center, and testing software is as core, and TCH test channel and test loop are controlled in unification, and whole test process realizes automatically working.
Description of drawings:
Fig. 1 is the frame diagram of existing measuring technology;
Fig. 2 is the synoptic diagram of existing voltage tester technology
Fig. 3 is the circuit diagram of existing measuring technology;
Fig. 4 is a test circuit schematic diagram of the present invention;
Fig. 5 is a test macro frame diagram of the present invention;
Fig. 6 is the process flow diagram of test macro of the present invention
Fig. 7 is single test loop schematic diagram;
Fig. 8 is a multi-channel circuit test loop schematic diagram.
10 '-insulation resistance meter; 20 '-programmed switch; 30 '-measured object; The 10-UPS power supply; The 20-industrial PC; The little reometer of 30-; The 40-programme-controlled dc power; The little rheotrope of 50-; 60-environmental testing case; The 70-specimen; The 100-display; 60 '-plug-in testing cassete.
For embodiment of the present invention better is described, the present invention is done detailed explanation below in conjunction with accompanying drawing.
Shown in Figure 4 is measuring technology schematic diagram of the present invention, and wherein R 1, R2 are measured resistance, and K 1, K2, K3, K4 are little rheotrope, and I is little reometer 30;, its principle of work is: under normal circumstances, K2 and K4 are closed, and K1 and K3 break off; Programme-controlled dc power 40 applies direct supply for measured object Rx (R1 or R2), and when arriving 60 seconds, K1 is closed, K2; K3 breaks off,, K4 is closed, little reometer I 30 measures the electric current that flows through R1, calculates the insulating resistance value of R1; K2 is closed then, and K1 breaks off and the K3 closure, and K4 breaks off, and the electric current of R2 is flow through in little reometer I measurement, calculates the insulating resistance value of R2; This method of testing is compared with existing method of testing, through switch, and K1, K2, K3, K4 can measure more sample 70, improves efficiency of measurement.
Fig. 5 is structural framing figure of the present invention; In this figure; Ups power 10 external external power sources; It is connected with industrial PC 20 through asynchronous transmission standard interface (RS232), and lasting, stable power is provided for industrial PC 20, and said industrial PC 20 is connected with little reometer 30, programme-controlled dc power 40, little rheotrope 50 through gpib interface, asynchronous transmission standard interface (RS232), asynchronous transmission standard interface (RS232) respectively.Said industrial PC 20 is a core controller of the present invention, and its inside is equipped with system controlling software, is used for analysis and processing to measurement data, and distributes electric current and voltage for each executive component, and controls the closed and disconnected of little current switch 50.
Said little reometer 30 is the Weak current signals that are used for measuring test loop; As shown in Figure 3, said test loop connects programme-controlled dc power 40, little rheotrope 50, little reometer 30, sample pcb board 70 successively by lead and constitutes, and said lead adopts the lead of 17 core band screen layers; Wherein, The measured object pcb board is arranged in the environmental testing case 60, and programme-controlled dc power 40, little rheotrope 50, little reometer 30 be arranged in the rack, and wherein the rack outside is provided with plug-in box 60; Plug-in box 60 conveniently is articulated in the both sides of rack through rack both sides bolt, makes things convenient for cabling, wiring.A test loop is a TCH test channel, and according to the designed channel of little rheotrope 50, said test loop can constitute the TCH test channel of 16 of N, and wherein N is a natural number, and preferential embodiment of the present invention is that said TCH test channel is 256 roads.
With reference to shown in Figure 5; Shown in little rheotrope 50 be respectively programme-controlled dc power 40, little reometer 30, industrial PC 20, ups power in rack inside through lead and link to each other 10; It also links to each other through the measured object pcb board of outer knot box 60 and environmental testing case 70, and said programme-controlled dc power 40 also links to each other with industrial PC 20 through asynchronous transmission standard interface (RS232) except linking to each other with little rheotrope 50; Link to each other with little reometer 30 with ups power through lead; Said industrial PC 20 is the core of test macro, and its inside is equipped with testing system software, and said system software is that system can analyze and handle test result; And send instruction and give programme-controlled dc power 40 and little rheotrope 50, realize the conversion of test loop and TCH test channel.
According to Ohm law, R=U/I is that programme-controlled dc power is applied to the voltage on the measured object according to said U, and said I is the numerical value on little reometer, through the calculating of system software, can judge the resistance of measured object, sees whether the measured object pcb board leaks electricity.
With reference to shown in Figure 6; The also available plug-in testing cassete 60' of said environmental testing case 60 replaces; Said industrial PC 20 links to each other with display 100, and said test result is input to display 100 through industrial PC and expresses intuitively, makes things convenient for tester's observation and adjustment detecting information.Said ups power 10 is respectively and connects programme-controlled dc power 40, and test macro control box, little rheotrope 50 link to each other, and said ups power 10 is returned programme-controlled dc power 50 and with industrial PC 20 uninterrupted, continuous power supply is provided.
Fig. 7 is the synoptic diagram of single channel test loop; Can observe out the circuit theory of test loop in the figure clearly; Specimen 70 is connected between programme-controlled dc power 40 and the little rheotrope 50 through lead, and so-called little rheotrope 50 is respectively K switch 1, K switch 2, K switch 1 by three switch in parallel; Open K2, can calculate the resistance value of measured object according to Ohm law.
Shown in the measuring principle of Fig. 7 be that Fig. 6 is similar, just do not carry out repeated description here.
With reference to shown in Figure 5, shown in RS232, GBIP is respectively plug-in testing cassete interface, shown in plug-in test interface be arranged in the plug-in testing cassete.
With reference to shown in Figure 8; Said little rheotrope adopts an industrial PC control, shown in display is set on the industrial PC, can clearly come out through said display 100 to The measured results show; Shown in industrial PC be provided with 8 test integrated circuit boards and insert patterns; Every integrated circuit board is controlled 16 passages, and industrial PC makes up test loop through the action of instruction control passage.
With reference to Fig. 4,5,6,7,8 described little rheotropes are foundation and the switchings that are used for TCH test channel.Ups power: the power supply of assurance system, when external world's power supply sudden power, system alarm is preserved test data, prevents unexpected power down loss of data.Yellow copper sheet in the plug-in testing cassete is a test lead grounded shield copper bar, guarantees that all test b NC shells link to each other with screen layer, improves system's interference free performance.Red PCB is the positive source connection strap, and 16 passage positive sources all link together through a pcb board, and Installation and Debugging are convenient.Plug-in box can be articulated in the both sides of rack easily through the both sides bolt, makes things convenient for client's cabling, wiring.Plug-in box is connected to the rack rear portion through the lead of 17 core band screen layers, through using 17 core aviation plugs to be connected with rack, constitutes test loop.Plug-in box can be articulated in the both sides of rack easily through the both sides bolt, makes things convenient for client's cabling, wiring.Plug-in box is connected to the rack rear portion through the lead of 17 core band screen layers, through using 17 core aviation plugs to be connected with rack, constitutes test loop.Wherein adopt independently UPS electric power system, make test macro can guarantee the reliability of test data, can guarantee that testing tool does not damage when sudden power, test data is not lost.Can break off bias voltage in the moment that puncturing appears in the TCH test channel point-to-point transmission, the protection testing apparatus.Native system can divide into groups hyperchannel to test according to the test request of specimen different size, can make test macro in one or more test casings, load different test voltages and bias voltage respectively simultaneously.TCH test channel can expand according to customer requirement, maximum extendible 256 passages.
The present invention adopts complete Chinese hommization human-computer interaction interface, improves the test display efficiency.Native system adopts the testing current method, and antijamming capability is strong, and measuring accuracy is high:
Fig. 1, Fig. 2 and Fig. 3 are electric current and the voltage tester principle and the synoptic diagram of prior art, give measured resistance RX when power supply and apply test voltage; Produce 1 electric current I in the loop; Voltage table is measured the voltage on the sample resistance R, I=V1/ R, known sample resistance with record voltage; Calculate electric current I in the loop, again RX=V/I; Shortcoming is that test is inaccurate, because sample resistance can divide to walk part of V 1 with total voltage V, the voltage that is obtained on the measured resistance R can't reach the desired test voltage of insulation resistance standard.The test macro control box is responsible for programmable power supply is divided into groups; Maximum configurable 6 groups of programmable power supplys, the instruction action that high resistant test control box is sent through accepting industrial computer, the testing current integrated circuit board and the reometer that configure in the gating software; Make up the test loop passage, for test is prepared.