CN1245295A - Detector for metal object - Google Patents
Detector for metal object Download PDFInfo
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- CN1245295A CN1245295A CN99106773A CN99106773A CN1245295A CN 1245295 A CN1245295 A CN 1245295A CN 99106773 A CN99106773 A CN 99106773A CN 99106773 A CN99106773 A CN 99106773A CN 1245295 A CN1245295 A CN 1245295A
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- mentioned
- sniffer
- circuit
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- time constant
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B67—OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
- B67C—CLEANING, FILLING WITH LIQUIDS OR SEMILIQUIDS, OR EMPTYING, OF BOTTLES, JARS, CANS, CASKS, BARRELS, OR SIMILAR CONTAINERS, NOT OTHERWISE PROVIDED FOR; FUNNELS
- B67C11/00—Funnels, e.g. for liquids
- B67C11/02—Funnels, e.g. for liquids without discharge valves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B67—OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
- B67C—CLEANING, FILLING WITH LIQUIDS OR SEMILIQUIDS, OR EMPTYING, OF BOTTLES, JARS, CANS, CASKS, BARRELS, OR SIMILAR CONTAINERS, NOT OTHERWISE PROVIDED FOR; FUNNELS
- B67C11/00—Funnels, e.g. for liquids
- B67C2011/30—Funnels, e.g. for liquids comprising venting means
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- Geophysics And Detection Of Objects (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The invention provides a kind of apparatus for testing the availability of metal object by using the transient phenomenon of RL series circuit. The structure includes an RL series circuit composed of an inductive coil (L) disposed in the proximity of a DUT (device under test) and a resistor combined with the coil; and a processing circuit (W, T, G) for detecting the transient phenomenon variation generated in accordance with the transient characteristics of the RL series circuit while applying a DC voltage to the RL series circuit and displaying the test result of the DUT.
Description
The present invention relates to be used for the sniffer of use coil that metal is surveyed.
As the method that use coil is in the past surveyed metal, representative method has three kinds.
In the 1st kind of method in the past, pass to alternating current in coil at metal detection.In case inspected object arrives on the coil, the inductance of coil changes, and causes that thus electric current changes and alternating voltage changes.Detect this variation of AC voltage, detect metal.
In the 2nd kind of method in the past, will send coil and receiving coil and be adjacent to be provided with.In the time of on inspected object arrives these coils, the signal of responding on the receiving coil changes.Utilize and detect this signal variation, detect metal.
In the 3rd kind of method in the past, use reference oscillation circuit, detection to reach the detection coil that is connected with oscillatory circuit with this detection with oscillatory circuit.Be detected object and in a single day arrive on the coil, detection changes with oscillation frequency.Compare by oscillation frequency and the benchmark oscillation frequency that this has been changed, detect metal.
In addition, stable for the action that makes detection in above-mentioned method, the situation of having added microcomputer is also arranged.
Above-mentioned any method all be utilize when metal approaching the phenomenon that the inductance of this coil changes when being applied with the coil of alternating current come metal is surveyed.Therefore, need apply alternating current continuously, and must possess the oscillatory circuit that produces interchange usefulness coil.Therefore, exist the many shortcomings of number of elements.
In addition, in the mode in the past, owing to essential the oscillatory circuit of metal object sniffer is driven regularly, therefore, exist the shortcoming more than the power consumption.In addition, because mode power consumption in the past is many, exists and to drive the shortcoming that makes equipment miniaturization with compact battery.
In addition, in the mode in the past,, must make the oscillatory circuit instability in order to improve the detection sensitivity of metal object sniffer.That is, must on constituting, make oscillatory circuit be easy to be subjected to from externalities.Yet, owing to make the oscillatory circuit instability, brought the metal object sniffer action unsettled shortcoming that becomes.For example, the action of the metal object sniffer that is provided with summer to winter become unstable, perhaps opposite, the action of the metal object sniffer that be provided with winter to summer become unstable.That is,, then exist the shortcoming that is easy to be subjected to influences such as environment in case improved the detection sensitivity of metal object sniffer.
In addition, in the mode in the past, when interchange oscillator that the frequency that is produced is comparable to the frequency of metal object sniffer was near the metal object sniffer, the metal object sniffer received from the signal that exchanges oscillator and amplifies.Its result exists the shortcoming that causes the misoperation of metal object sniffer.So, exist produce with the frequency same frequency of metal object sniffer or close frequencies exchange oscillator near, can not use the shortcoming of metal object sniffer.
In addition, because the additional mini computing machine exists the shortcoming that metal object sniffer price uprises for the action stability of keeping the metal object sniffer.
The purpose of this invention is to provide the metal object sniffer that above-mentioned shortcoming is improved.
The purpose of this invention is to provide a kind of metal object sniffer in addition, this device uses has the detection that is connected in series with coil and resistance but do not have the circuit of electric capacity, utilization applies transition (transition) phenomenon of DC voltage when this circuit, and metal object is surveyed.
Sniffer of the present invention has:
The RL series circuit, its formation comprises: check target object detection coil (L), it is provided with to such an extent that can approaching may contain the inspected object of checking target object; Resistance (R), it and above-mentioned coil are connected in series;
Treatment circuit (W, T, G), this treatment circuit is according to the feature of the benchmark transient of above-mentioned RL series circuit, characteristic variations to the transient that produced when above-mentioned RL series circuit has applied DC voltage detects, according to this testing result, the output expression has or not the check result of above-mentioned inspection target object.
In addition, sniffer of the present invention has:
The RL series circuit, its formation comprises: check target object detection coil (L), it is provided with to such an extent that can approaching may contain the inspected object of checking target object; Resistance (R), it and above-mentioned coil are connected in series;
Control module (S) is used for controlling applying DC voltage by power supply (E) to above-mentioned RL series circuit;
Testing circuit (W), this circuit are exported the corresponding detection signal of time constant with above-mentioned RL series circuit according to the transient that has produced when above-mentioned RL series circuit has applied DC voltage;
Treatment circuit (T, G), this circuit is according to the pairing reference signal of constant reference time of above-mentioned detection signal and pre-determined RL series circuit, variation to the time constant of above-mentioned RL series circuit detects, and changes according to this, produces the signal that expression has or not above-mentioned inspection target object.
In addition, in above-mentioned sniffer, above-mentioned control module contains switch element (S), and this unit is connected/cut off the supply of above-mentioned DC voltage at interval with the official hour based on the said reference time constant.
In addition, in above-mentioned sniffer, above-mentioned testing circuit has and generates the pulse have with the corresponding time span of above-mentioned time constant as above-mentioned detection signal, and with the unit (W) of its output.
In addition, in above-mentioned sniffer, above-mentioned treatment circuit has: set time pulse signal generation circuit (T), this circuit produce the basic pulse that has with said reference time constant time corresponding length as the said reference signal; With according to by the above-mentioned pulse of above-mentioned testing circuit output with by the said reference signal of said fixing time pulse signal generation circuit output, produce the unit (G) whether expression has detected the signal of above-mentioned inspection target object.
In addition, in other of the above-mentioned treatment circuit of above-mentioned sniffer constituted, above-mentioned treatment circuit had: the unit of the value of said reference time constant being stored the line output of going forward side by side as the said reference signal; Burst length is measured circuit, and this circuit is to measuring the signal of this burst length length of output expression by the time span of the above-mentioned pulse of above-mentioned testing circuit output; And, produce the unit whether expression has detected the signal of above-mentioned inspection target object according to the time span of above-mentioned pulse and the value of said reference time constant.
In addition, in above-mentioned sniffer, the said reference time constant has identical value with near the time constant that does not have the above-mentioned RL series circuit when this coil produced the material of electromagnetic effect above-mentioned coil, perhaps, has the value more smaller than this time constant.
In addition, in above-mentioned sniffer, above-mentioned inspection target object is a metal.
In addition, in above-mentioned sniffer, the time constant of above-mentioned RL series circuit is derived by the signal waveform of the feature of this RL series circuit transient of expression.
In addition, in above-mentioned sniffer, the signal waveform of representing above-mentioned transient feature is the signal waveform of expression change in voltage.
According to the formation of metal detecting device of the present invention, have the effect that can reduce number of elements, and, have the effect of can qurer making.
In addition, according to the formation of metal detecting device of the present invention,, also has the effect that stably to move even do not use microcomputer etc.
In addition, according to the formation of metal detecting device of the present invention, power consumption reduces, and has and can drive by enough compact batteries, realizes the effect of miniaturization.
In addition, according to the formation of metal detecting device of the present invention, even have produce with the frequency same frequency of this metal object sniffer or close frequencies exchange oscillator near, also can use the effect of this metal object sniffer.
In addition, by the resistance R of the circuit of metal detecting device of the present invention and the part beyond the coil L are constituted with digital circuit, has the effect that can reduce temperature drift.
Fig. 1 is used for figure that principle of the present invention is described.
Fig. 2 is the diagrammatic sketch that the voltage of presentation graphs 1 circuit changed along with the time.(a) variation of voltage between the A-C of presentation graphs 1; (b) variation of voltage between the B-C of presentation graphs 1.
Fig. 3 represents an embodiment of metal object sniffer of the present invention.
Fig. 4 is signal waveform on the each several part of metal detecting device of presentation graphs 3 and the diagrammatic sketch that concerns between the time, the signal waveform when being illustrated in the signal waveform when having metal object on the coil and not having metal object on coil.
Among the present invention, utilize transient to survey the inductance variation of metal detection with coil.And, its testing result is analyzed, and it is transformed to signal exports.
Fig. 1 is used for figure that principle of the present invention is described, shows the RL circuit.Among the figure, L uses coil for surveying; R is a resistance; S is a switch; E is a power supply.These elements are connected in series as shown in Figure 1.A, B, C are the points that expression is measured the voltage of this circuit.In addition, the inductance value of establishing coil L is L (H); The resistance value of resistance R is R (Ω); The magnitude of voltage of power supply E is E (V).
Fig. 2 is the diagrammatic sketch that the voltage of presentation graphs 1 circuit changed along with the time.The variation of voltage between the A-C of Fig. 2 (a) presentation graphs 1; The variation of voltage between the B-C of Fig. 2 (b) presentation graphs 1.
In case the switch S of Fig. 1 circuit is connected, between A-C, apply DC voltage E (V), then the two ends of coil L promptly between the B-C, present the waveform of the expression transient shown in Fig. 2 (b).In this waveform, voltage E (V) reaches (1-0.632) E (V), the time τ (timeconstant) when promptly reaching 0.368E (V), and τ=L/R represents by calculating formula.Calculating formula the width of signal, is the size of timeconstant as can be seen thus, and L is proportional with inductance value.
Object that the magnetic field of coil L is exerted an influence such as metal object are during near this coil L, and the inductance value of coil L changes.Because inductance value changes, and causes that the time constant of RL circuit changes.
On this RL circuit, for example known set time pulse signal generation circuit (generation has the circuit of the pulse of given time length) in the combination.Length by set time pulse that pulse signal generation circuit produces, compare, can detect having or not of metal object with the time constant of being measured (shape by pulse is represented) to this.
In addition, on this RL circuit, the known burst length is measured circuit (circuit that the time span of paired pulses is measured) in the combination.Utilize this burst length to measure circuit time constant is measured, survey having or not of metal object.That is,, detect having or not of metal object by the time constant measured and time constant (for example, not having the time constant of the RL circuit when being detected object) as benchmark are compared.
The calculating formula of this time constant can the application of differential circuit and any one of integrating circuit.Here, the sniffer with the derivative-type circuit that an end of testing circuit can be connected with 0 current potential is described.
Fig. 3 represents an embodiment of metal object sniffer of the present invention.
Among the figure, L uses coil for surveying; R is a resistance.S is a switch, and E is the driving power of coil L and resistance R.The end of coil L is connected with ground, and the other end is connected with an end of resistance R.The other end of resistance R is connected with switch S.Switch S is to being switched on or off to resistance R and coil L electrical power supplied by power supply E.In addition, the inductance value of establishing coil L is L (H); The resistance value of resistance R is R (Ω); The magnitude of voltage of power supply E is E (V).
W is a waveform shaping circuit, and it will be transformed to square wave by the detected signal waveform of coil L.That is, waveform shaping circuit W is based on the detected waveform of coil L, produces the square wave that has length equal time (width) with the voltage of coil L from the time that E (V) changes to 0.368E (V).I is a phase inverter, is connected in the outgoing side of waveform shaping circuit W, with the reversal of poles of the square wave of waveform shaping circuit W output.
T is a time-pulse generator, and it produces the time constant that can predict, is that length is same as near time constant when not having metal object coil L or the pulse of slightly lacking than this time constant length based on calculating formula τ=L/R.The width of this pulse is used as benchmark, judge near coil L, whether there being metal object.
D is the drive signal that is connected with time-pulse generator T with switch S.Switch S and time-pulse generator T drive when drive signal D is supplied to.
G is a gate circuit, and an input end is connected in the outgoing side of time-pulse generator T, and another input end is connected in the outgoing side of phase inverter I.Gate circuit G is to comparing by the signal of time-pulse generator T output with by waveform shaping circuit W output and by the signal of phase inverter I counter-rotating.O is the output signal by gate circuit G output, is that expression is by the signal of time-pulse generator T output and the signal of the difference of the signal of being exported by phase inverter I.
In addition, the arrow among Fig. 3 is represented the flow direction of signal.
Then, the action to metal detecting device shown in Figure 3 describes.
When switch S and time-pulse generator T were supplied to drive signal D, both drove switch S and time-pulse generator T.
In a single day switch S receives drive signal D, just switches to on-state by off-state, with driving power E and resistance R and coil L connection.Therefore, electric current flows to resistance R and coil L from driving power E.At this moment, on resistance R and coil L transient takes place.The waveform of the change in voltage of waveform shaping circuit W his-and-hers watches timberline circle L detects.
Here, have metal object near the coil L and do not existing under the situation of metal object, the time span of detected waveform is that the width of signal is different.
Waveform shaping circuit W rise time length and detected waveform voltage value change to the square wave that time of 0.368E (V) equates from E (V), and with its output.Square wave by waveform shaping circuit W output reverses at phase inverter I, offers gate circuit G.
On the other hand, time-pulse generator T will be both the pulse signal of measured length (identical or than this time constant length weak point slightly) with the time constant that can predict based on calculating formula τ=L/R offer gate circuit G.
In a single day gate circuit G receives the signal supplied by time-pulse generator T, just with by phase inverter I signal supplied compares, and the signal O of difference of the length of these two signals of expression is exported.According to this signal O, judge having or not of metal object.
In addition, in the time can not directly using, can use microcomputer that output signal is handled, or use after utilizing one shot multivibrator etc. that signal time is extended for necessary length because of the time of output signal O is very short.
In addition, survey action, can apply DC voltage periodically resistance R and coil L in order to implement continuously.For this reason, for example, can switch S be connected/cut off with the set cycle.In addition, also can use pulse producer as power supply.Here, for example with the application time of DC voltage, be set under the state that metal object does not exert an influence to coil L, when connecting voltage and supplying with the transient of RL circuit arrive end during (or than its slightly length during), and with the non-application time of DC voltage, be set at cut off the transient of voltage when supplying with arrive end during (or than its slightly length during).
In addition, the part beyond the resistance R of the circuit of metal detecting device of the present invention and the coil L can constitute with digital circuit.
In addition, also computing machine etc. can be made up with metal detecting device of the present invention, make that to survey action more stable.In addition, also can be by using a computer, the operating state of metal detecting device of the present invention is managed.
Claims (16)
1. sniffer has:
The RL series circuit, its formation comprises: check target object detection coil (L), it is provided with to such an extent that can approaching may contain the inspected object of checking target object; Resistance (R), it and above-mentioned coil are connected in series; And
Treatment circuit (W, T, G), it is according to the feature of the benchmark transient of above-mentioned RL series circuit, characteristic variations to the transient that produced when above-mentioned RL series circuit has applied DC voltage detects, according to this testing result, the output expression has or not the check result of above-mentioned inspection target object.
2. sniffer has:
The RL series circuit, its formation comprises: check target object detection coil (L), it is provided with to such an extent that can approaching may contain the inspected object of checking target object; Resistance (R), it and above-mentioned coil are connected in series;
Control module (S) is used for controlling applying DC voltage by power supply (E) to above-mentioned RL series circuit;
Testing circuit (W), it exports the corresponding detection signal of time constant with above-mentioned RL series circuit according to the transient that has produced when above-mentioned RL series circuit has applied DC voltage; And
Treatment circuit (T, G), it is according to the pairing reference signal of constant reference time of above-mentioned detection signal and pre-determined RL series circuit, variation to the time constant of above-mentioned RL series circuit detects, and changes according to this, produces the signal that expression has or not above-mentioned inspection target object.
3. sniffer as claimed in claim 2 is characterized in that, above-mentioned testing circuit has and generates the pulse have with the corresponding time span of above-mentioned time constant as above-mentioned detection signal, and with the unit (W) of its output.
4. sniffer as claimed in claim 3 is characterized in that, above-mentioned treatment circuit has:
Set time pulse signal generation circuit (T), its generation have basic pulse with said reference time constant time corresponding length as the said reference signal; And
According to by the above-mentioned pulse of above-mentioned testing circuit output and the said reference signal of exporting by said fixing time pulse signal generation circuit, produce the unit (G) whether expression has detected the signal of above-mentioned inspection target object.
5. sniffer as claimed in claim 3 is characterized in that, above-mentioned treatment circuit has:
The value of said reference time constant is stored the unit of the line output of going forward side by side as the said reference signal;
Burst length is measured circuit, and it is to measuring the signal of this burst length length of output expression by the time span of the above-mentioned pulse of above-mentioned testing circuit output; And
According to the time span of above-mentioned pulse and the value of said reference time constant, produce the unit whether expression has detected the signal of above-mentioned inspection target object.
6. as each described sniffer among the claim 2 to 5, it is characterized in that, the said reference time constant has identical value with near the time constant that does not have the above-mentioned RL series circuit when this coil produced the material of electromagnetic effect above-mentioned coil, perhaps, have the value more smaller than this time constant.
7. as each described sniffer among the claim 2 to 5, it is characterized in that the time constant of above-mentioned RL series circuit is derived by the signal waveform of the feature of this RL series circuit transient of expression.
8. sniffer as claimed in claim 6 is characterized in that, the time constant of above-mentioned RL series circuit is derived by the signal waveform of the feature of this RL series circuit transient of expression.
9. as each described sniffer among the claim 2 to 5, it is characterized in that above-mentioned control module contains switch element (S), it is connected/cuts off the supply of above-mentioned DC voltage at interval with the official hour based on the said reference time constant.
10. sniffer as claimed in claim 6 is characterized in that, above-mentioned control module contains switch element (S), and it is connected/cut off the supply of above-mentioned DC voltage at interval with the official hour based on the said reference time constant.
11. sniffer as claimed in claim 7 is characterized in that, above-mentioned control module contains switch element (S), and it is connected/cut off the supply of above-mentioned DC voltage at interval with the official hour based on the said reference time constant.
12. sniffer as claimed in claim 8 is characterized in that, above-mentioned control module contains switch element (S), and it is connected/cut off the supply of above-mentioned DC voltage at interval with the official hour based on the said reference time constant.
13. sniffer as claimed in claim 7 is characterized in that, the signal waveform of representing the feature of above-mentioned transient is the signal waveform of expression change in voltage.
14. sniffer as claimed in claim 8 is characterized in that, the signal waveform of representing the feature of above-mentioned transient is the signal waveform of expression change in voltage.
15. sniffer as claimed in claim 11 is characterized in that, the signal waveform of representing the feature of above-mentioned transient is the signal waveform of expression change in voltage.
16. sniffer as claimed in claim 12 is characterized in that, the signal waveform of representing the feature of above-mentioned transient is the signal waveform of expression change in voltage.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP179546/98 | 1998-05-22 | ||
| JP10179546A JPH11337658A (en) | 1998-05-22 | 1998-05-22 | Device for detecting metal object |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1245295A true CN1245295A (en) | 2000-02-23 |
Family
ID=16067648
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN99106773A Pending CN1245295A (en) | 1998-05-22 | 1999-05-21 | Detector for metal object |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH11337658A (en) |
| KR (1) | KR100370484B1 (en) |
| CN (1) | CN1245295A (en) |
| TW (1) | TWI239393B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100414266C (en) * | 2000-11-30 | 2008-08-27 | 罗伯特·博施有限公司 | Device for determining at least one parameter of flowing medium |
| CN102598075A (en) * | 2009-08-03 | 2012-07-18 | 传感电子有限责任公司 | Electronic article surveillance system with metal detection capability and interference detector resulting in adjustment |
| CN101688925B (en) * | 2007-01-15 | 2012-12-26 | 拉皮斯坎系统股份有限公司 | Detector systems |
| US11280898B2 (en) | 2014-03-07 | 2022-03-22 | Rapiscan Systems, Inc. | Radar-based baggage and parcel inspection systems |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102096110A (en) * | 2010-11-19 | 2011-06-15 | 北京交通大学 | Metal detecting device suitable for belt conveying mechanism |
-
1998
- 1998-05-22 JP JP10179546A patent/JPH11337658A/en active Pending
-
1999
- 1999-05-13 TW TW088107806A patent/TWI239393B/en not_active IP Right Cessation
- 1999-05-21 KR KR10-1999-0018420A patent/KR100370484B1/en not_active IP Right Cessation
- 1999-05-21 CN CN99106773A patent/CN1245295A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100414266C (en) * | 2000-11-30 | 2008-08-27 | 罗伯特·博施有限公司 | Device for determining at least one parameter of flowing medium |
| CN101688925B (en) * | 2007-01-15 | 2012-12-26 | 拉皮斯坎系统股份有限公司 | Detector systems |
| US8552722B2 (en) | 2007-01-15 | 2013-10-08 | Rapiscan Systems, Inc. | Detector systems |
| US20140167744A1 (en) * | 2007-01-15 | 2014-06-19 | Rapiscan Systems, Inc. | Detector Systems |
| US9714920B2 (en) * | 2007-01-15 | 2017-07-25 | Rapiscan Systems, Inc. | Detector systems |
| CN102598075A (en) * | 2009-08-03 | 2012-07-18 | 传感电子有限责任公司 | Electronic article surveillance system with metal detection capability and interference detector resulting in adjustment |
| CN102598075B (en) * | 2009-08-03 | 2016-03-30 | 泰科消防及安全有限公司 | For system and method and the security system of electronic article monitoring system |
| US11280898B2 (en) | 2014-03-07 | 2022-03-22 | Rapiscan Systems, Inc. | Radar-based baggage and parcel inspection systems |
Also Published As
| Publication number | Publication date |
|---|---|
| KR19990088474A (en) | 1999-12-27 |
| JPH11337658A (en) | 1999-12-10 |
| KR100370484B1 (en) | 2003-01-29 |
| TWI239393B (en) | 2005-09-11 |
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