CN1693914A

CN1693914A - Transistor Meter

Info

Publication number: CN1693914A
Application number: CN 200510009987
Authority: CN
Inventors: 石广范; 闫广明; 李季刚; 王冠然; 成责果
Original assignee: Heilongjiang University
Current assignee: Heilongjiang University
Priority date: 2005-05-18
Filing date: 2005-05-18
Publication date: 2005-11-09
Anticipated expiration: 2025-05-18
Also published as: CN100370268C

Abstract

A transistor measuring device is an instrument that identifies polarity of each pin of transistor and various parameters. It is composed of a carry computer, a control unit, a measure interface circuit and a direct current power supply with adjustable press. computer and control unit communication interfaces are linked together; One of control unit exportation interfaces is linked with power supply control interface; The other interface of control unit is linked with inputend of interface circuit input; control unit exportation interface is linked with control unit input interface, and power supply output interface is linked with the power supply. control unit provides different voltages to the transistor pins through control unit and people can judge these pins attributes according to whether the PN stanza can transmit electric current. power supply works when people are measuring parameters. computer adopts a normal personal computer and control unit chooses a low cost, small volume chip. Moreover,the situation that computer is linked with control unit through a main line of USB makes the invention more popular.

Description

Transistor measuring instrument

Technical field:

The present invention relates to a kind of instrument of discerning each pin polarity of transistor and measuring the transistor parameters.

Background technology:

The surveying instrument of traditional transistor parameters generally adopts the complicated hardware circuit to realize, causes finished product price height, function singleness, and bulky, usable range and precision are limited.Though also occurred intelligentized transistor measuring instrument device at present, these instruments are many to be core with the special purpose computer and to dispose corresponding special software and the hardware integrated circuit board, because this kind scheme hardware radix is bigger, so volume is still huge, costs an arm and a leg.

Summary of the invention:

The purpose of this invention is to provide a kind of transistor measuring instrument, to overcome the big and defect of high cost of existing transistor measuring instrument device complex structure, volume.The present invention includes host computer 1, control module 2, measure interface circuit 3 and tunable voltage dc power supply 4, the communication port of host computer 1 is connected by the communication port of usb bus with control module 2, an output terminal of control module 2 connects the controlled end of tunable voltage dc power supply 4, another output terminal of control module 2 connects an input end measuring interface circuit 3, the output terminal of measuring interface circuit 3 connects the input end of control module 2, and the output terminal of tunable voltage dc power supply 4 connects the power end of measuring interface circuit 3.When measuring instrument of the present invention is worked, another input end of measuring interface circuit 3 connects tested transistor, according to transistorized PN junction characteristic, be that P knot adds positive voltage and N knot when adding negative voltage, electric current meeting conducting, when N knot add positive voltage, when the P knot adds negative voltage, electric current can conducting, control module 2 applies high-low level at transistorized different pins respectively through measuring interface circuit 3, save P, the N attribute whether conducting just can be differentiated each pin of transistor according to PN, thereby realize differentiating the function of transistor pin polarity.When measuring parameters such as transistorized amplification coefficient, breakdown reverse voltage, reverse leakage current when needs, according to the transistor polarity of having measured, tunable voltage dc power supply 4 is received transistorized respective pin, when changing the output voltage of tunable voltage dc power supply 4 transistorized relevant parameter is changed Input Control Element 2 and just can draw transistorized parameters value.The present invention can also be used to measuring resistance and the voltage stabilizing value of zener diode, the resistance of thermistor etc. of resistance commonly used.Host computer 1 of the present invention adopts universal personal computer to get final product, therefore reduced the cost of this tester, control module 2 selects for use the singlechip chip that cost is low, volume is little to get final product, and use usb bus between host computer 1 and the control module 2, improved versatility of the present invention, the present invention have volume small and exquisite, be easy to carry, easy to install and cheap advantage.

Description of drawings:

Fig. 1 is a structural representation of the present invention, and Fig. 2 is an electrical block diagram of the present invention, and Fig. 3 is the structural representation of embodiment four, and Fig. 4 is the program flow diagram in the host computer in the embodiment four.

Embodiment:

Embodiment one: specify present embodiment below in conjunction with Fig. 1.Present embodiment is made up of host computer 1, control module 2, measurement interface circuit 3 and tunable voltage dc power supply 4, the communication port of host computer 1 is connected by the communication port of usb bus with control module 2, an output terminal of control module 2 connects the controlled end of tunable voltage dc power supply 4, another output terminal of control module 2 connects an input end measuring interface circuit 3, the output terminal of measuring interface circuit 3 connects the input end of control module 2, and the output terminal of tunable voltage dc power supply 4 connects the power end of measuring interface circuit 3.

Embodiment two: specify present embodiment below in conjunction with Fig. 2.The difference of present embodiment and embodiment one is: control module 2 is selected singlechip chip U1 for use, the model of singlechip chip U1 is PIC16C765, the pin 23 of singlechip chip U1 is connected host computer 1 with pin 24 by usb bus, measure interface circuit 3 by the 23 resistance R 23, the 24 resistance R 24, the 25 resistance R 25, a relay J 1, No. two relay J 2, No. three relay J 3, the second diode N2, the 3rd diode N3, the 4th diode N4 and slot J6 form, one end of the 23 resistance R 23 connects the pin 19 of singlechip chip U1, the other end of the 23 resistance R 23 connects the pin 2 of singlechip chip U1 and the normally closed contact of a relay J 1, the end of the solenoid K1 of a relay J 1 connects the negative electrode of the power supply VCC and the second diode N2, the other end of solenoid K1 connects the anode of the second diode N2 and the pin 8 of singlechip chip U1, one end of the 24 resistance R 24 connects the pin 20 of singlechip chip U1, the other end of the 24 resistance R 24 connects the pin 3 of singlechip chip U1 and the normally closed contact of No. two relay J 2, the end of the solenoid K2 of No. two relay J 2 connects the negative electrode of power supply VCC and the 3rd diode N3, the other end of solenoid K2 connects the anode of the 3rd diode N3 and the pin 9 of singlechip chip U1, one end of the 25 resistance R 25 connects the pin 21 of singlechip chip U1, the other end of the 25 resistance R 25 connects the pin 4 of singlechip chip U1 and the normally closed contact of No. three relay J 3, the end of the solenoid K3 of No. three relay J 3 connects the negative electrode of power supply VCC and the 4th diode N4, the other end of solenoid K3 connects the static contact of 10, numbers relay J 1 of pin of the anode of the 4th diode N4 and singlechip chip U1, the static contact of the static contact of No. two relay J 2 and No. three relay J 3 is connected on three pins of slot J6; Tunable voltage dc power supply 4 is by transformer T1, rectification circuit U2, triode Q1, first capacitor C 1, second capacitor C 2, the 5th diode N5, the 30 resistance R 30, the 29 resistance R 29, the 28 resistance R 28, the 4th resistance R 4, the 5th resistance R 5 and the 6th resistance R 6 are formed, one end on the former limit of transformer T1 connects the negative electrode of power supply VCC and the 5th diode N5, the anode of the 5th diode N5 connects an end of the 30 resistance R 30 and the collector of triode Q1, the other end of the 30 resistance R 30 connects the other end on the former limit of transformer T1, the base stage of triode Q1 connects an end of the 29 resistance R 29 and an end of the 28 resistance R 28, the other end of the 29 resistance R 29 connects emitter and the ground connection of triode Q1, the other end of the 28 resistance R 28 connects the pin 17 of singlechip chip U1, the two ends of transformer T1 secondary connect two input ends of rectification circuit U2 respectively, the cathode output end of rectification circuit U2 connects the positive pole of first capacitor C 1, one end of the positive pole of second capacitor C 2 and the 4th resistance R 4, the cathode output end of rectification circuit U2 connects the negative pole of first capacitor C 1, the negative pole of second capacitor C 2 and ground connection, the other end of the 4th resistance R 4 connects the normally opened contact of a relay J 1, the normally opened contact of No. two relay J 2, one end of the normally opened contact of No. three relay J 3 and the 5th resistance R 5, the other end of the 5th resistance R 5 connects the pin 5 of singlechip chip U1 and an end of the 6th resistance R 6, the other end ground connection of resistance R 6.

If in slot J6, insert a crystal diode, realize by control module 2 and the measurement interface circuit transistorized both positive and negative polarity of 3 identifications following steps by way of example with the software in the host computer 1: the pin 8 of (1) singlechip chip U1, pin 9 and pin 10 are general I/O pin, when identification, all be changed to high level (logical one), the pin 19 of singlechip chip U1, pin 20 and pin 21 are general I/O pin, is the pin 2 of singlechip chip U1, pin 3 and pin 4 usefulness software setting A/D conversion input pin, and reference voltage is+5V.(2) allow pin 19 output+5V, pin 20 output 0V, the pin 21 of U1 be changed to input (this pin is a high-impedance state at input state), the A/D transformation result that at this moment reads on the pin 3 is 0V; (3) allow pin 20 output+5V, pin 19 output 0V, the pin 21 of U1 be changed to input (this pin is a high-impedance state at input state) then, at this moment the A/D transformation result of the pin 2 of U1 is 0V, and hence one can see that, between 1,2 pins of slot J6 for opening circuit; (4) allow pin 20 output+5V, pin 21 output 0V, the pin 19 of U1 be changed to input (this pin is a high-impedance state at input state), at this moment the A/D transformation result of pin 4 is 0V; (5) allow pin 21 output+5V, pin 20 output 0V, the pin 19 of singlechip chip U1 be changed to input (this pin is a high-impedance state at input state) then, at this moment the A/D transformation result of pin 3 is not 0V, and hence one can see that, is path between 2,3 pins of slot J6, and unidirectional conducting, be PN junction; (6) allow the pin 21 output+5V of singlechip chip U1, pin 19 export 0V, pin 20 high resistants, at this moment the A/D transformation result of pin 2 is 0V, allows pin 19 output+5V, pin 21 export 0V, pin 20 high resistants then, and at this moment pin 4A/D transformation result is 0V, hence one can see that, between 1,3 pins of slot J6 for opening circuit; So in fact judged the positive and negative electrode of diode.So just the different PN junction characteristic that has separately according to them just can be judged different electron devices.Can also be according to the parameter of the outcome measurement different components of judging, as: the resistance of resistance commonly used, the voltage stabilizing value of zener diode etc.And the triode pin is differentiated identical with diode pin discrimination principles, and triode can be regarded 2 diodes that link together as.The measurement of voltage breakdown is to carry out on the basis that pin is differentiated, and after the collector of triode, emitter, base stage had been determined, the principle that reverse pressurization has snowslide phenomenon according to P, N knot was measured voltage breakdown.Now illustrate: on J6, insert a transistor, the emitter of triode, base stage and collector be pin 19, pin 20 and the pin 21 of corresponding singlechip chip U1 respectively, collector---the base break down voltage when the measurement emitter current is zero: the pin 19 of (1) singlechip chip U1 is changed to input (this pin is a high-impedance state at input state), pin 20 is changed to input (this pin is a high-impedance state at input state), pin 21 output 0V, pin 9 output 0V (relay J 2 of pin 20 correspondences switches to high-pressure side).(2) imported the primary voltage value in 0.1 second and in single-chip microcomputer, carry out an A/D conversion by pin 5 every intervals of singlechip chip U1, obtaining the A/D transforming numerical subtracts each other with numerical value last time, up to subtracting each other the result is 0, promptly reaches the snowslide flex point, and this voltage is this P, N junction breakdown voltage.Emitter---collector---principle of emitter voltage breakdown and test set electrode---the base break down voltage V when base break down voltage and base current are zero when the measurement collector current is zero _CboPrinciple identical.The measurement of reverse leakage current also is to carry out on the basis that pin is differentiated, after knowing the collector, emitter, base stage of triode, reverse pressurization has the principle of snowslide phenomenon according to P, N knot, can measure voltage breakdown, and a period of time before snowslide, P, N economize on electricity stream should be stable, and Nei current value is called as reverse leakage current during this period of time.Just can obtain reverse leakage current with the breakdown reverse voltage that records divided by sample resistance.

Embodiment three: specify present embodiment below in conjunction with Fig. 2.The difference of present embodiment and embodiment two is: it also comprises warning circuit 6, warning circuit 6 is made up of the 3rd resistance R 3, field effect transistor M11 and light emitting diode N1, one end of the 3rd resistance R 3 connects an end of the 5th resistance R 5, the other end of the 3rd resistance R 3 connects the drain electrode of field effect transistor M11, the source ground of field effect transistor M11, the negative electrode of the grid sending and receiving optical diode N1 of field effect transistor M11, the pin 29 of the anode order sheet machine chip U1 of light emitting diode N1.Other composition is identical with embodiment two with annexation.When parameters such as the amplification coefficient of test transistor, breakdown reverse voltage, reverse leakage current, the tunable voltage dc power supply 4 of this testing tool is switched on work, and high voltage direct current is dangerous to the people, so provide warning function by light emitting diode N1 to the people.

Embodiment four: specify present embodiment below in conjunction with Fig. 3 and Fig. 4.The difference of present embodiment and embodiment one is that it also comprises thermistor R20, the 21 resistance R 21, voltage sampling circuit 7, A/D change-over circuit 8 and host computer 1, the termination power VAA of thermistor R20, the other end of thermistor R20 is by the 21 resistance R 21 ground connection, voltage sampling circuit 7 is connected the magnitude of voltage that is used to gather thermistor R20 on the two ends of thermistor R20, the output terminal of voltage sampling circuit 7 connects the input end of A/D change-over circuit 8, and the output terminal of A/D change-over circuit 8 connects the input end of host computer 1; The program in the host computer 1 of operating in comprises the steps: to import the resistance value database (producer provides the resistance value data of this thermistor at each temperature spot to the consumer when buying thermistor) 001 of corresponding each temperature spot of thermistor R20; Host computer 1 is gathered this voltage drop of thermistor R20 constantly by voltage sampling circuit 7 and A/D change-over circuit 8, utilizes the magnitude of voltage of known power supply VAA and the resistance of the 21 resistance R 21 to try to achieve this resistance ￡ 002 of thermistor R20 constantly; From the resistance value database of corresponding each temperature spot of thermistor R20, find above and below resistance ￡ and with immediate adjacent resistance ￡ 1 and adjacent resistance ￡ 2 and the pairing temperature value thereof down of resistance ￡, determine the relative position of resistance ￡ between last adjacent resistance ￡ 1 and following adjacent resistance ￡ 2, utilize Lagrange interpolation formula to try to achieve this temperature value 003 of thermistor R20 constantly then.Present embodiment can provide environment temperature at that time when measuring transistorized parameters, make transistorized measurement more accurate, more complete.Other composition is identical with embodiment one with connected mode.

Claims

1. The transistor measuring instrument is characterized in that it comprises a host computer (1), a control unit (2), a measurement interface circuit (3) and an adjustable voltage DC power supply (4), and the communication port of the host computer (1) is connected via USB The bus is connected to the communication port of the control unit (2), one output end of the control unit (2) is connected to the controlled end of the adjustable voltage DC power supply (4), and the other output end of the control unit (2) is connected to the measurement interface circuit One input terminal of (3), the output terminal of the measurement interface circuit (3) is connected to the input terminal of the control unit (2), and the output terminal of the adjustable voltage DC power supply (4) is connected to the power supply terminal of the measurement interface circuit (3).

2. The transistor measuring instrument according to claim 1, characterized in that the control unit (2) selects a single-chip microcomputer chip (U1), and pins 23 and 24 of the single-chip microcomputer chip (U1) are connected to the host computer (1) through the USB bus.

3. The transistor measuring instrument according to claim 2, characterized in that the measurement interface circuit (3) consists of the twenty-third resistor (R23), the twenty-fourth resistor (R24), the twenty-fifth resistor (R25), Relay No. 1 (J1), Relay No. 2 (J2), Relay No. 3 (J3), Diode 2 (N2), Diode 3 (N3), Diode 4 (N4) and slots (J6), one end of the twenty-third resistor (R23) is connected to the pin 19 of the single-chip microcomputer chip (U1), and the other end of the twenty-third resistor (R23) is connected to the pin 2 of the single-chip microcomputer chip (U1) and the No. 1 relay ( The normally closed contact of J1), one end of the electromagnetic coil (K1) of the No. 1 relay (J1) is connected to the power supply (VCC) and the cathode of the second diode (N2), and the other end of the electromagnetic coil (K1) is connected to the second The anode of the diode (N2) is connected to the pin 8 of the single-chip microcomputer chip (U1), one end of the twenty-fourth resistor (R24) is connected to the pin 20 of the single-chip microcomputer chip (U1), and the other end of the twenty-fourth resistor (R24) is connected to Pin 3 of the single-chip microcomputer chip (U1) and the normally closed contact of the second relay (J2), one end of the electromagnetic coil (K2) of the second relay (J2) is connected to the power supply (VCC) and the third diode (N3) The cathode, the other end of the electromagnetic coil (K2) is connected to the anode of the third diode (N3) and the pin 9 of the single-chip microcomputer chip (U1), and one end of the twenty-fifth resistor (R25) is connected to the pin 21 of the single-chip microcomputer chip (U1) , the other end of the twenty-fifth resistor (R25) is connected to pin 4 of the microcontroller chip (U1) and the normally closed contact of the third relay (J3), and one end of the electromagnetic coil (K3) of the third relay (J3) is connected to the power supply (VCC) and the cathode of the fourth diode (N4), the other end of the electromagnetic coil (K3) is connected to the anode of the fourth diode (N4) and the pin 10 of the single-chip microcomputer chip (U1), and the No. 1 relay (J1) The static contacts of the No. 2 relay (J2) and the No. 3 relay (J3) are respectively connected to the three pins of the slot (J6);

4. The transistor measuring instrument according to claim 3, characterized in that the adjustable voltage DC power supply (4) consists of a transformer (T1), a rectifier circuit (U2), a triode (Q1), a first capacitor (C1), a second Capacitor (C2), fifth diode (N5), thirtieth resistor (R30), twenty-ninth resistor (R29), twenty-eighth resistor (R28), fourth resistor (R4), fifth resistor (R5) and the sixth resistor (R6), one end of the primary side of the transformer (T1) is connected to the power supply (VCC) and the cathode of the fifth diode (N5), and the anode of the fifth diode (N5) is connected to the third One end of the tenth resistor (R30) is connected to the collector of the triode (Q1), the other end of the thirtieth resistor (R30) is connected to the other end of the primary side of the transformer (T1), and the base of the triode (Q1) is connected to the twenty-ninth resistor One end of (R29) and one end of the twenty-eighth resistor (R28), the other end of the twenty-ninth resistor (R29) is connected to the emitter of the triode (Q1) and grounded, and the other end of the twenty-eighth resistor (R28) Connect pin 17 of the single-chip microcomputer chip (U1), the two ends of the secondary side of the transformer (T1) are respectively connected to the two input terminals of the rectification circuit (U2), and the positive output terminal of the rectification circuit (U2) is connected to the positive pole of the first capacitor (C1) , the positive pole of the second capacitor (C2) and one end of the fourth resistor (R4), the negative output terminal of the rectifier circuit (U2) is connected to the negative pole of the first capacitor (C1), the negative pole of the second capacitor (C2) and grounded, the second The other end of the four resistors (R4) is connected to the normally open contact of the No. 1 relay (J1), the normally open contact of the No. 2 relay (J2), the normally open contact of the No. 3 relay (J3) and the fifth resistor (R5). ), the other end of the fifth resistor (R5) is connected to pin 5 of the microcontroller chip (U1) and one end of the sixth resistor (R6), and the other end of the sixth resistor (R6) is grounded.

5. The transistor measuring instrument according to claim 4, characterized in that it also includes a warning circuit (6), and the warning circuit (6) is composed of a third resistor (R3), a field effect transistor (M11) and a light emitting diode (N1) One end of the third resistor (R3) is connected to one end of the fifth resistor (R5), the other end of the third resistor (R3) is connected to the drain of the field effect transistor (M11), and the source of the field effect transistor (M11) is grounded , the gate of the field effect transistor (M11) is connected to the cathode of the light-emitting diode (N1), and the anode of the light-emitting diode (N1) is connected to the pin 29 of the single-chip microcomputer chip (U1).

6. The transistor measuring instrument according to claim 1, characterized in that it also includes a thermistor (R20), a twenty-first resistor (R21), a voltage sampling circuit (7), and an A/D conversion circuit (8) and the upper computer (1), one end of the thermistor (R20) is connected to the power supply (VAA), the other end of the thermistor (R20) is grounded through the twenty-first resistor (R21), and the voltage sampling circuit (7) is connected to the thermal Collect the voltage value of the thermistor (R20) on both ends of the sensitive resistor (R20), the output end of the voltage sampling circuit (7) is connected to the input end of the A/D conversion circuit (8), and the A/D conversion circuit (8) The output end of the upper computer (1) is connected to the input end of the upper computer (1); the program running in the upper computer (1) includes the following steps: input the resistance value database (001) of the thermistor (R20) corresponding to each temperature point; the upper computer (1) ) through the voltage sampling circuit (7) and the A/D conversion circuit (8) to collect the voltage drop of the thermistor (R20) at this moment, using the voltage value of the known power supply (VAA) and the twenty-first resistor (R21) Obtain the resistance value (￡) (002) of the thermistor (R20) at this moment; From the resistance value database of the thermistor (R20) corresponding to each temperature point, find out whether it is higher than or lower than the resistance value (￡ ) and the upper neighbor resistance value (￡1) and lower neighbor resistance value (￡2) and the corresponding temperature value to the resistance value (￡), determine the resistance value (￡) on the upper neighbor resistance value (￡1 ) and the relative position between the lower adjacent resistance value (￡2), and then use the Lagrangian interpolation formula to obtain the temperature value (003) of the thermistor (R20) at this moment.