CN101315395B

CN101315395B - Intelligent multifunctional measuring apparatus and method thereof

Info

Publication number: CN101315395B
Application number: CN2007101067032A
Authority: CN
Inventors: 黎俊良
Original assignee: Cyrustek Co
Current assignee: Cyrustek Co
Priority date: 2007-05-28
Filing date: 2007-05-28
Publication date: 2011-06-15
Anticipated expiration: 2027-05-28
Also published as: CN101315395A

Abstract

The invention provides a measuring device with the function of automatically determining the varieties of objects to be measured. The measuring device comprises a controlling unit, a switching unit, a detection unit and a measuring unit, wherein the controlling unit is used for providing a plurality of scanning information in sequence; the switching unit is composed of a plurality of test circuits, is connected with the controlling unit, executes the switching action according to the scanning information, and is used for connecting the test circuits with input ends; the detection unit is connected with the switching unit and performs the comparison to the voltage of the input ends in sequence through a comparison circuit, and compared results are returned to the controlling unit, so that the varieties of the objects to be measured are determined through the controlling unit according to the comparison results; and the measuring unit is connected with the controlling unit and selects a corresponding measuring circuit for the measurement of the objects to be measured according to the determined results of the controlling unit, and measured results are displayed on a display device.

Description

Intelligent multifunction measuring set and measuring method thereof

Technical field

The present invention relates to a kind of multi-functional determinand proving installation and the method for test thereof, and be particularly related to and a kind ofly need not selector switch and can have the measurement mechanism of automatic judgement determinand kind and the method for test thereof, for example a kind of universal electric meter (Multi-meter) of automatic judgement determinand kind.

Background technology

Function universal electric meter (Automatic function selectingmulti-meter) all can show measured value with digital form with the result who measures more than the various automatic tests at present, for example show D. C. value or interchange value, resistance value or capacitance, diode or circuit pathways test result etc.Though also some universal electric meter declares to have intelligent autorun, it is that functional select switch on artificial adjustment universal electric meter is to the position of determinand that right its is referred to as intelligent autorun, when for example determinand is resistance, then before measuring, need earlier the position (or be called gear) of the functional select switch adjustment on the universal electric meter (or being called switching) to measuring resistance, use the probe of input end that the resistance that will test is measured then, the universal electric meter of the intelligent autorun of this moment can automatically select suitable resistance value to measure, and does not need the tester oneself will be from high value (for example: 100M ohm) test step by step until suitable resistance value is arranged; By for example in the time will carrying out open test to determinand, also as long as with the gear of the functional select switch on the universal electric meter to open test, universal electric meter test and show that determinand is open circuit or short circuit automatically then.

The universal electric meter of above-mentioned prior art is at U.S. Patent number the 4th, 556,986,4,588,983,5742221 and 6646562, wherein in the U.S. Patent number the 6646562nd, just clearly disclosing its universal electric meter can be when measuring voltage, need not manually to select direct current or alternating voltage function, also do not need manually to select suitable scope; For example during measuring resistance, it does not need earlier the circuit under test decapacitation again; For example having impressed voltage to be present in determinand again and can't measure the time, then can jump out of an ohm function automatically, and suitable selection and display voltage value, is that direct current or exchange all can be tested automatically simultaneously.

Though present universal electric meter can be operated simply, but during to actual will the detection to the circuit of a complexity, it still needs to judge earlier why kind of determinand, by after manually the functional select switch on the universal electric meter being adjusted to suitable gear, can measure desired result then by the autorun on the universal electric meter.So process can reduce the benefit and the inconvenience of work, especially when selecting when wrong the doubt time of generation; Or after finishing using, the resistance measurement gear is not left in the functional select switch adjustment on the universal electric meter, and make running down of battery on the universal electric meter etc.

In view of the prior art universal electric meter on the operation convenience and on the power saving performance at battery consumption, still have the space of improvement.

Summary of the invention

In above-mentioned background of invention, in order to solve above-mentioned universal electric meter, the invention provides one and detect flow process fast on the operation convenience and the problem on the power saving performance at battery consumption, can detect circuit unit kind commonly used with interior at 50ms.When what determinand input end do not take over, controller can be judged into open-circuit condition with input end, and can not enter measurement pattern this moment, but carried out the detecting flow process repeatedly, and measurement mechanism then is in idle state, so can reach purpose of power saving.Therefore, a fundamental purpose of the present invention is to provide a kind of device with automatic judgement determinand kind,, need to carry out suitable measurement when the operation in order to the universal electric meter that solves above-mentioned tradition to after the kind of switching determinand by functional select switch.

Another fundamental purpose of the present invention is to provide a kind of measurement mechanism with automatic judgement determinand kind, make the present invention's measurement mechanism can judge the kind of determinand automatically, so do not need the functions of use selector switch on the present invention's the measurement mechanism by a plurality of circuit configurations.

Another fundamental purpose of the present invention is providing a kind of measurement mechanism with automatic judgement determinand kind, whether it can go out input end by Auto-Sensing has determinand and decision according to this whether will enter test procedure, so the present invention's measurement mechanism can reach the requirement of power saving.

According to above-mentioned purpose, the present invention at first proposes a kind of device of automatic judgement determinand kind, comprising: a control module that is used for providing in regular turn a plurality of scanning informations; A switch unit of forming by a plurality of test circuit, it is connected with control module and carries out change action in regular turn according to a plurality of scanning informations, in order in regular turn a plurality of test circuits are connected with this input end; A detecting unit, it is connected with switch unit and in regular turn the voltage of input end is compared by a comparator circuit, and will be than returning to control module than the result, so that control module is judged the kind of determinand according to this comparative result

The present invention then proposes a kind of measurement mechanism with automatic judgement determinand kind, comprising: a control module that is used for providing in regular turn a plurality of scanning informations; A switch unit of forming by a plurality of test circuit, it is connected with control module and carries out change action in regular turn according to a plurality of scanning informations, in order to should be connected with this input end by a plurality of test circuits in regular turn; A detecting unit, it is connected with switch unit and in regular turn the voltage of input end is compared by a comparator circuit, and will be than returning to control module than the result, so that control module is judged the kind of determinand according to this comparative result; And a measuring unit, is connected with control module and determinand is measured according to the corresponding metering circuit of judged result selection of control module, and will measure the results are shown in display device.

The present invention then reintroduces a kind of intelligent multi-functional universal electric meter, be provided with display device, in order to show the numerical value of a plurality of measurement patterns and measurement, and converting switch device, in order to a plurality of switching preference patterns to be provided, to carry out the measurement of signal specific or particular test, and pair of input terminals, a plurality of measurement patterns comprise autoscan judgment model (SCAN) at least, can judge classification automatically with this this determinand that input terminal is connected, and after the classification of finishing this determinand is judged, can optionally carry out numerical measuring to this determinand automatically.

The present invention then reintroduces a kind of measuring method of intelligent multi-functional universal electric meter, comprising: carry out scanning sequence, control module provides a plurality of scanning informations in regular turn; Carry out changeover program, the switch unit of being made up of a plurality of test circuit configurations to carry out change action in regular turn according to a plurality of scanning informations, in order in regular turn a plurality of test circuit configurations are connected with the determinand that input end links to each other; Carry out comparison program, in regular turn the voltage of determinand is compared, to produce comparative result by the comparator circuit in the detecting unit; Carry out determining program, judge the kind of this determinand by control module according to comparative result; And when judging input end, promptly continue to carry out this scanning sequence, otherwise promptly carry out process of measurement for open circuit, according to the corresponding metering circuit of judged result selection of control module determinand is measured, and will measure the results are shown in display device.

Description of drawings

Fig. 1 is the function block diagram of the present invention's circuit;

Fig. 2 is the schematic flow sheet of the present invention's detecting and measurement;

Fig. 3 A to Fig. 3 B is the synoptic diagram that the present invention judges the positive bias circuit configurations of diode;

Fig. 4 A to Fig. 4 B is the synoptic diagram that the present invention judges the negative bias circuit configuration of diode;

Fig. 5 is the synoptic diagram of charging circuit configuration of the present invention's judgement capacitor;

Fig. 6 is the synoptic diagram of discharge circuit configuration of the present invention's judgement capacitor;

Fig. 7 is the synoptic diagram of the present invention's the electrical circuit configurations of judgement open circuit;

Fig. 8 A to Fig. 8 D is the present invention's the judgement capacitor and the waveform synoptic diagram of resistance;

Fig. 9 is the measurement mechanism of the automatic judgement determinand of having of the present invention kind;

Figure 10 A and Figure 10 B, promptly table 1 (A) and table 1 (B) be the present invention different determinands respectively between the voltage region of input end with and corresponding digital judgement table.

The main element description of symbols

1 universal electric meter

2 display device

3 change-over switches

3A active signal measurement pattern

3B cpm signal measurement pattern

The 3C shutdown mode

4 additional function keys

5 input terminals

10 control modules

20 switch units

30 detecting units

40 A/D conversion circuits

50 data processing circuits

60 display device

70 short circuit detecting units

80 hummers

90 gear control circuits

The VDD positive voltage

The VSS negative voltage

Embodiment

The present invention is a kind of device of automatic judgement determinand kind in this direction of inquiring into, particularly a kind of measurement mechanism with automatic judgement determinand kind.In order to understand the present invention up hill and dale, the detailed determining step and the composition of decision circuitry thereof will be proposed in following description.Apparently, execution of the present invention is not defined in the specific details that the technician had the knack of of the measurement mechanism of automatic judgement determinand kind.On the other hand, the measurement mechanism of well-known automatic judgement determinand kind or measuring process etc. are not described in the details, with the restriction of avoiding causing the present invention unnecessary.Preferred embodiment meeting of the present invention is described in detail as follows, yet except these were described in detail, the present invention can also implement in other embodiments widely, and scope of the present invention do not limited, and it is as the criterion with claim.

Please refer to Fig. 1, the circuit function block scheme of the measurement mechanism of automatic judgement determinand kind of the present invention comprises that control module (CONTROLLER) 10, switch unit (SWITCH) 20, detecting unit (TYPE DETECTOR) 30, A/D conversion circuit (A/D CONVERTER) 40, data processing circuit (DATA PROCESSING CIRCUIT) 50, display device (DISPLAY) 60, short circuit detecting unit (SHORT DETECTOR) 70, hummer (BUZZER) 80 and gear control circuit (RANGE CONTROL CIRCUIT) 90 or the like form.

At first, as shown in Figure 1, the present invention's the device of judging the determinand kind automatically provides a plurality of scanning informations in regular turn by a control module 10; Then these a plurality of scanning informations are sent to switch unit 20, a scanning information was carried out change action in regular turn more than switch unit 20 then can provide according to control module 10, in order in regular turn a plurality of test circuits are connected with input end; For example when control module 10 provided the sweep signal of a diode, it can provide the positive bias sweep signal (P_DIO_CHK) of a diode earlier, then, then provided the negative bias sweep signal (N_DIO_CHK) of a diode again.

When switch unit 20 received the P_DIO_CHK signal that control module 10 transmitted, switch unit 20 can be carried out a change action, so that input end and Fig. 3 A are connected with circuit configurations among Fig. 3 B.At this moment, the end points T2 in the circuit configurations is connected to positive bias VDD, for example: VDD=3V, end points T3 then is connected to earth point (GND), and end points T2 also can be connected with the comparer (not shown) in the detecting unit 30 simultaneously, in order to the current potential of detecting input end, wherein R1 is a big resistance, R _PTCBe a divider resistance, and R1 R _PTC, in a preferred embodiment, R _PTCThermistor can be used for holding circuit.When input end with after Fig. 3 A is connected, at this moment, if input end connects one forward during the diode of (forward connection), as shown in Figure 3A, the current potential of end points T2 (being VT2) will be by the conducting current potential of strangulation (clamping) at diode, for example: VT2=0.7V.The current potential of VT2 will be to drop within the scope of " 0V " and "+Vr " this moment, wherein+and Vr is a current potential less than positive bias VDD.At this moment, if when the diode of input end is connected into oppositely (reverse connection), shown in Fig. 3 B, because diode can not be switched on, VT2 current potential at this moment is R _PTCWith the result after the R1 dividing potential drop, therefore work as divider resistance and be designed to R1〉R _PTCThe time, then the current potential of VT2 will all be bordering on positive bias VDD.

This scanning result is as shown in the diode row of Figure 10 A (table 1 (A)), and Figure 10 B (table 1 (B)) is the digital watch after corresponding figures 10A (table 1 (the A)) conversion.Therefore, can find out clearly that the scanning result of the P_DIO_CHK positive bias sweep signal that control module 10 provided is " 01 " (diode is connected into forward) and " 10 " (diode is connected into oppositely) by Figure 10 B (table 1 (B)).

Then, control module 10 can then provide the negative bias sweep signal (N_DIO_CHK) of a diode, and at this moment, switch unit 20 can be carried out a change action, so that input end and Fig. 4 A are connected with circuit configurations among Fig. 4 B.Therefore, when input end was connected with Fig. 4 A, then the result according to Fig. 3 can learn that the current potential of VT2 will approach negative bias VSS; And when input end with after Fig. 4 B is connected, then the current potential of VT2 will drop on 0V between-the Vr.This scanning result can clearly be found out by Figure 10 B (table 1 (B)), and the scanning result of the N_DIO_CHK negative bias sweep signal that control module 10 provided reaches " 10 " for " 01 ".

At this moment, the comprehensive result who has passed through P_DIO_CHK and two sweep signals of N_DIO_CHK is: the scanning result when diode is connected into forward is " 0101 "; The scanning result that is connected into when reverse when diode is " 1010 ".Clearly, Figure 10 B (table 1 (B)) listed it " 0101 " (forward connection) is that P_DIO_CHK and two sweep signals of N_DIO_CHK finish the comprehensive result of back with " 1010 " (reverse connection).Be stressed that at this, why the present invention will use above-mentioned circuit to the measurement of diode, be because for the user, when measuring, do not know the polarity of diode probably, therefore, the present invention is divided into the circuit of judging diode in deterministic process: (a) determinand is connected into forward state and (b) if determinand is connected into reverse state.By above-mentioned process, clearly, it is to be connected into forward or oppositely, its last scanning result all can determine that it is diode by the Digital Logic of table 1 that the present invention can ignore determinand.

In addition, the scope of the VT2 current potential that P_DIO_CHK on Figure 10 A (table 1 (A)) and N_DIO_CHK signal are measured, through after the comparison of comparer, the output result of comparer will be lockable (latching) when P_DIO_CHK and N_DIO_CHK signal ended, and change into Digital Logic (digital logic), wherein Figure 10 B (table 1 (B)) is the result that Figure 10 A (table 1 (A)) changes into Digital Logic.To emphasize at this, the present invention's Digital Logic is built among the control module 10 in being, after detecting unit 30 sends back control module 10 with the Digital Logic of determinand, after the action (Look-up Table) of tabling look-up, for example, when Digital Logic is " 0101 " or " 1010 ", then can judge determinand immediately is diode.Will will emphasize more that at this action of tabling look-up is just can carry out after all scanning processes finish, first talking about the action of tabling look-up at this is for the relation of scanning result and Digital Logic table is described.

After above-mentioned P_DIO_CHK and these two sweep signals of N_DIO_CHK, little electric capacity among table 1 (B) Figure 10 B (table 1 (B)) is identical with the Digital Logic of big resistance, simultaneously big electric capacity is also identical with the Digital Logic of small resistor, therefore, under current state, table look-up and to determine that it is a diode, and resistance and electric capacity still must be differentiated by following scanning motion.

Then, control module 10 can be sent the measuring-signal of an electric capacity comprising the signal (CAP_CHK1) of a charging and the signal (CAP_CHK2) of a discharge.When switch unit 20 received CAP_CHK1 that control module 10 transmitted or CAP_CHK2 signal, switch unit 20 can be carried out a change action, so that input end is connected with circuit configurations among Fig. 5 and Fig. 6.

Fig. 5 is the charging circuit configuration of an electric capacity, the CAP_CHK1 that is transmitted when control module 10 is connected input end through switch unit 20 with Fig. 5, at this moment, end points T2 is connected to negative voltage VSS, and end points T1 is connected with comparer in the detecting unit 30, with the current potential of detecting input end; In addition, end points T3 is suspension joint (floating).And the CAP_CHK2 that is transmitted when control module 10 is connected input end through switch unit 20 with Fig. 6, and at this moment, end points T1 is connected to GND, and end points T2 then is connected with comparer in the detecting unit 30, and to detect the current potential of input end, end points T3 is floating.Clearly, during the CAP_CHK1 signal, the determinand that is positioned at input end passes through R _PTCAnd negative voltage VSS charge (charge); And during the CAP_CHK2 signal, the determinand that is positioned at input end can be by R2 towards GND discharge (dis-charge).

Then, please refer to figure A-Fig. 8 D, change situation according to the electric capacity of the shown difference size of the circuit configurations of Fig. 5 of the present invention and Fig. 6 and the voltage and the time of resistance, wherein the determinand of Fig. 8 A is little electric capacity, the determinand of Fig. 8 B is big electric capacity, the determinand of 8C figure is big resistance, and the determinand of Fig. 8 D is a small resistor.In the present embodiment, the resistance value of R2 is much larger than R _PTC

Please refer to shown in Fig. 8 A and Fig. 8 B, the present invention's electric capacity is judged oscillogram, and its longitudinal axis is input voltage (V _INP), and transverse axis is a time shaft, and wherein Fig. 8 A is a waveform synoptic diagram of judging little electric capacity, figure B then is a waveform synoptic diagram of judging big electric capacity.When the current potential of input end meets following two benchmark (criteria), then determine that it is electric capacity, promptly first: before the CAP_CHK1 signal ended, the absolute value of the current potential of input end, | VINP| must be greater than | Vr1|, and second: in the CAP_CHK2 signal begins during this whole section of time (pre-determined time) to a setting, | V _INP| must be always greater than | Vr2|.Clearly, can find out that no matter the determinand of input end is big electric capacity or little electric capacity, all can meet above-mentioned two benchmark by Fig. 8 A and Fig. 8 B.

If when determinand is resistance, it also measures the resistance value of determinand by the circuit configurations of Fig. 5 and Fig. 6, and this moment, the resistance value of determinand will be by determinand and R _PTCDividing potential drop determine.Therefore, shown in Fig. 8 C, during the CAP_CHK1 signal, V _INPCurrent potential will reach rapidly one very accurate near the position of VSS, so can meet " absolute value of input end current potential | V _INP| must be greater than | Vr1| " first benchmark; And when entering the CAP_CHK2 signal, V _INPThe position that also can reach GND rapidly is accurate, at this moment, the time of a setting (pre-determined time) before, | V _INP| just less than | Vr2|, thus its fail to meet " the CAP_CHK2 signal begin during to the time of a setting (pre-determinedtime) this whole section in it | V _INP| must be always greater than | Vr2| " second benchmark.In addition, shown in Fig. 8 D, when being input as small resistor, before the CAP_CHK1 signal ended, | V _INP| not greater than | Vr1|, thus fail to meet first benchmark, and when entering the CAP_CHK2 signal, V _INPThe position that reaches GND again rapidly is accurate, so also fail to meet second benchmark.So, when being input as resistance, can not meet above two benchmark simultaneously.

At last, after the scanning of finishing the electric capacity judgement, control module 10 can transmit an open circuit sweep signal (OPEN_CHK) again, and this moment, switch unit 20 was connected input end with Fig. 7, and wherein Fig. 7 is the circuit configurations of OPEN_CHK, its end points T3 is connected to reference potential (Vref), end points T1 then is connected with comparer in the detecting unit 30, and with the current potential of detecting input end, and end points T2 is floating, wherein, R1 is a big resistance.When input end is open, the voltage of end points T1 (VT1) will equal reference potential (Vref).In addition, if when being input as one greatly to the time above the resistance of measurement range, this kind situation also classifies as open-circuit condition (open circuit), this moment, the voltage (VT1) of end points T1 also can be very near reference potential (Vref), therefore, can open-circuit condition and resistance be differentiated out by VT1 in the circuit configurations of Fig. 7 and the relation of Verf.

By above-mentioned in sense mode (detect mode), control module 10 can produce five sweep signals of P_DIO_CHK, N_DIO_CHK, CAP_CHK1, CAP_CHK2, OPEN_CHK etc. in regular turn in each detecting cycle (cycle) after, after treating that these five sweep signals all finish, carry out the action of tabling look-up this moment, so that be that diode, electric capacity, resistance or open distinguish with determinand.This judgment mode is as follows:

1. earlier with the scanning result of P_DIO_CHK and N_DIO_CHK, earlier diode (Diode) is picked out by tabling look-up;

2. when being not diode as if determinand, then, again electric capacity is picked out by the scanning result of CAP_CHK1 and CAP_CHK2;

3. if determinand is not a diode neither electric capacity the time, whether judges the input end open circuit by OPEN_CHK at last, otherwise enter resistance measurement, and judge that with this determinand is a resistance.

And the sweep signal of an above-mentioned cycle can be controlled in the 50ms, that is to say, therefore the present invention's measurement mechanism can reach fast and purpose of power saving at 50ms with the interior kind of judging determinand automatically.If when the judged result of sense mode is OPEN, represent that promptly input end does not have any determinand, this moment, control module 10 will carry out the scanning of sense mode repeatedly, just be in sense mode always, when determinand is connected input end, to be judged out rapidly, then enter measurement pattern.Before advancing measurement pattern, A/D conversion circuit 40 can remain on the pattern that does not start (POWER DOWN).Therefore, when input does not all have determinand, can be in a battery saving mode.

In addition, in the present embodiment, when sense mode when carrying out, short circuit detecting unit 70 (SHORT DETECTOR) also can be activated simultaneously, when short circuit detecting unit 70 detects the current potential of input end when very low, representing this moment input end is Low ESR, and short circuit this moment detecting unit 70 can feed signals interrupt (interrupt) control modules 10, allow hummer 80 (BUZZER) pipe simultaneously, and enter the measurement pattern of continuity (continuity).For example, when carrying out resistance measurement, when short circuit detecting unit 70 detects short circuit, will directly jump out sense mode and enter measurement pattern immediately, output resistance also shows resistance values by display unit 60 then.

When sense mode has been judged determinand for which kind of assembly, enter measurement pattern (measure mode) immediately, that will measure then the results are shown in display device 60.To emphasize at this, the present invention's unique point is in the function of existing universal electric meter, add the decision circuitry of a determinand, and judge the classification of determinand automatically by this decision circuitry after, for example tell diode, electric capacity, resistance or open, utilize known metering circuit that determinand is measured immediately, can be the 4th wherein with known metering circuit, 556,986,4, disclosed metering circuit on 588,983 and No. 6646562 United States Patent (USP)s is not limited this present invention.

When sense mode has been judged determinand for behind which kind of assembly, immediately by a measuring unit, determinand is measured, and wherein the present invention's measuring unit is made up of A/D conversion circuit 40, data processing circuit 50 and a gear control circuit 90 (RANGE CONTROL CIRCUIT).When entering measurement pattern, the analog signal conversion that A/D conversion circuit 40 begins input end is a digital signal, after process data processing circuit 50 converts numerical value to afterwards, exports measurement result to display device 60.Gear control circuit 90 then before entering sense mode, is judged the scope of wanting handover measurement according to the numerical value of data processing circuit 50 conversions next time.Repeating detecting and the action of measuring then always.

Then, please refer to Fig. 2, the present invention's the process flow diagram of judging the measurement mechanism of determinand kind automatically.As shown in Figure 2, before measuring, can be introduced into sense mode, to differentiate the kind of determinand.This moment, control module 10 produced P_DIO_CHK in regular turn, N_DIO_CHK, CAP_CHK1, CAP_CHK2, five sweep signals such as OPEN_CHK, as scanning sequence 100 to 500, switch unit 20 is carried out changeover program according to these sweep signals then, to switch different circuit configurations to input end, and then carry out a comparison program by the comparer in the detecting unit 30, the input end current potential size of the circuit configurations that this program is more different, and behind the end cycle to be detected, after detecting unit 30 sends back control module 10 with the Digital Logic of determinand, carry out a determining program, this determining program is the judgement 700 of carrying out diode in regular turn, the judgement 800 of electric capacity, or the judgement 900 of open circuit, when the judged result of open circuit is " non-open circuit ", judge that then determinand is a resistance.

In addition, the present invention's embodiment is when carrying out determining program, and the order of its judgement is in regular turn: diode, electric capacity, resistance or open.If after judging the kind of determinand, then enter measurement pattern.If judge when input end is OPEN, then do not enter measurement pattern, and continue to carry out the detecting of next cycle.Same, in the present invention's measuring method, it also can carry out short circuit detection process 600 simultaneously when carrying out changeover program, as the detecting result of short circuit detection process 600 during for short circuit, promptly directly carry out the measurement of resistance value and will measure the results are shown in display device 60.In addition, can judge determinand because of determining program is big electric capacity/big resistance or little electric capacity/small resistor, therefore can select suitable measurement range to measure automatically, therefore can reach fast and purpose of power saving.

Then please continue with reference to Fig. 9 the schematic appearance of the present invention's intelligent multifunction universal electric meter.As shown in Figure 9, the present invention's the universal electric meter operation instructions with autoscan function is as follows: universal electric meter 1 is provided with display device 2, can show present affiliated measurement function and measure numerical value, wherein the SCAN representative is in autoscan intelligent decision pattern at present, and the AUTO representative is in general automatic trip stop measurement pattern at present, then represents as for MANU to be in general manual static stall measurement pattern at present; Universal electric meter 1 also is provided with a change-over switch 3 and is used for switching active signal, for example measurement pattern 3B of voltage measurement mode 3 A or passive component (for example resistance/diode/open short circuit), an or current measurement mode 3 C; Also be provided with a plurality of additional function keys 4 in addition on the universal electric meter 1, comprise measurement pattern function key (SEL), particular measurement numerical value function key (RANGE) and frequency measurement function key (VAHz); Universal electric meter 1 and be provided with pair of input terminals 5 in addition, can further be provided with test probe socket or probe (not shown) on it, wherein measurement pattern function key (SEL) also can be used as off switch, when the user pins the SEL key and reaches more than 2 seconds, then ammeter can cut out.

In a plurality of measurement patterns that the present invention's the universal electric meter with autoscan function 1 is had, at least comprise an autoscan judgment model (SCAN) decided at the higher level but not officially announced, it can judge the classification whether input end has determinand and can judge the determinand that is connected with input terminal 5 automatically at any time automatically, and after the classification of finishing determinand is judged, can optionally carry out numerical measuring to determinand automatically, the explanation in above-mentioned of circuit that it is detailed and deterministic process does not repeat them here.Next other operating function of universal electric meter 1 will be described.

When universal electric meter 1 switches to following time of active signal measurement pattern 3A, just carry out the measurement pattern of voltage (V) or electric current (A), but universal electric meter 1 autoscan is judged input signal characteristics and is automatically switched to interchange (AC) or direct current (DC) measurement pattern, it is 10M Ω that measuring process also can keep input impedance, to keep the security of measuring process.In addition, under the active signal measurement pattern, it also can use the SEL key in the additional function key 4, then can be switched to automatic trip stop measurement pattern (AUTO) by autoscan measurement pattern (SCAN) decided at the higher level but not officially announced to carry out AC measurment or direct current measurement pattern automatically.After switching to the alternating current-direct current pattern, can utilize additional function key RANGE to switch to manual static stall measurement pattern (MANU) again.For example, when on the DC voltage little alternating voltage being arranged, if we are chosen in when measuring under autoscan measurement pattern (SCAN) or the automatic trip stop measurement pattern (AUTO), clearly, universal electric meter 1 can show the value of reading of DC voltage on display device 2.If want to measure be little ac voltage signal on the DC voltage time, then can directly select AC measurment pattern (AC) by the SEL key in the additional function key 4, at this moment, universal electric meter 1 will show the value of reading of little ac voltage signal on display device 2.In addition, the additional function key of available VAHz selects to switch to the frequency measurement pattern under the active measurement pattern.

When universal electric meter 1 switches under the passive component measurement pattern 3B, universal electric meter 1 can be under autoscan judgment model (SCAN) decided at the higher level but not officially announced, autoscan is judged the input module characteristic, selects to enter resistance/diode/continuity measurement pattern automatically, to save control action and time.Certainly, under the passive component measurement pattern, also can use additional function key SEL, universal electric meter 1 is switched to general resistance, electric capacity, diode or continuity measurement pattern in regular turn by autoscan measurement pattern (SCAN) decided at the higher level but not officially announced.Same, also can switch to manual static stall measurement pattern (MANU) again with additional function key RANGE.

Be stressed that at this universal electric meter 1 of the present invention is when operation, the autoscan measurement pattern (SCAN) that enters promptly decided at the higher level but not officially announced in order to the kind of automatic judgement determinand, does not therefore need the selector switch of determinand; And change-over switch 3 and additional function key 4 etc. by the user with manual selection, therefore it only can select specific function is tested, and does not influence the reaching of autoscan arbitration functions of universal electric meter 1.In addition, the present invention's universal electric meter 1 can also affix have the value of reading demonstration maintenance (HOLD), (MAX/MIN) computing of the minimax value of reading or startup backlight function keys such as (BLT), but also can fully phase out these function key amount of allowing universal electric meters 1 simple to operateization of trying one's best, only need there be change-over switch to get final product, as shown in Figure 9 as active signal measurement or passive component measurement switching.

Apparently, according to the description among the top embodiment, the present invention has many corrections and difference.Therefore need be understood in the scope of its additional claim, except above-mentioned detailed description, the present invention can also implement widely in other embodiments.Above-mentioned is the present invention's preferred embodiment only, is not the claim in order to qualification the present invention; All other do not break away from the equivalence of being finished under the disclosed spirit and changes or modification, all should be included in the claim.

Claims

1. device of automatically judging the determinand kind comprises:

Control module provides a plurality of scanning informations in regular turn;

Switch unit, be made up of a plurality of test circuits, its first end connects with the input end that is connected with determinand, and its second end is connected with this control module, and carry out change action in regular turn according to these a plurality of scanning informations, in order to should be connected with this input end by a plurality of test circuits in regular turn; And

Detecting unit, its first end is connected with the 3rd end of this switch unit, and in regular turn the voltage of this input end is compared by comparator circuit, and comparative result is returned to this control module by second end;

Wherein the comparative result passed back according to this detecting unit of this control module is judged the kind of determinand.

2. device according to claim 1 is characterized in that also comprising the short circuit detecting unit, and its first end is connected with the 3rd end of this switch unit, and its second end then is connected to this control module.

3. device according to claim 2 is characterized in that this short circuit detecting unit further is connected with boom unit.

4. device according to claim 1 is characterized in that a plurality of scanning informations that this control module provides are diode in regular turn, is electric capacity secondly, is open test secondly again.

5. measurement mechanism of automatically judging the determinand kind comprises:

Control module provides a plurality of scanning informations in regular turn;

Switch unit, be made up of a plurality of test circuits, its first end connects with the input end that is connected with determinand, and its second end is connected with this control module, and carry out change action in regular turn according to these a plurality of scanning informations, in order to should be connected with this input end by a plurality of test circuits in regular turn;

Detecting unit, its first end is connected with the 3rd end of this switch unit, and in regular turn the voltage of this input end is compared by comparator circuit, and comparative result is returned to this control module by second end, so that this control module is judged the kind of determinand according to this comparative result; And

Measuring unit is connected with this control module and selects corresponding metering circuit that this determinand is measured according to the judged result of this control module, and measurement result is shown in display device.

6. the measuring method of an intelligent multi-functional universal electric meter comprises:

Carry out scanning sequence, control module provides a plurality of scanning informations in regular turn;

Carry out changeover program, come to carry out change action in regular turn, in order in regular turn a plurality of test circuit configurations are connected with the determinand that links to each other with input end according to these a plurality of scanning informations by switch unit;

Carry out comparison program, in regular turn the voltage of this determinand is compared, to produce comparative result by the comparator circuit in the detecting unit; And

Carry out determining program, judge the kind of this determinand by this control module according to this comparative result;

Wherein when judging this input end, promptly continue to carry out this scanning sequence, otherwise promptly carry out process of measurement for open circuit.