CA1159925A - Motion sensing system - Google Patents
Motion sensing systemInfo
- Publication number
- CA1159925A CA1159925A CA000403767A CA403767A CA1159925A CA 1159925 A CA1159925 A CA 1159925A CA 000403767 A CA000403767 A CA 000403767A CA 403767 A CA403767 A CA 403767A CA 1159925 A CA1159925 A CA 1159925A
- Authority
- CA
- Canada
- Prior art keywords
- tuned circuit
- motion
- oscillations
- amplitude
- oscillator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P13/00—Indicating or recording presence, absence, or direction, of movement
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/02—Mechanical actuation
- G08B13/14—Mechanical actuation by lifting or attempted removal of hand-portable articles
- G08B13/1436—Mechanical actuation by lifting or attempted removal of hand-portable articles with motion detection
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S73/00—Measuring and testing
- Y10S73/01—Vibration
Abstract
ABSTRACT
A motion sensing system having an oscillator with a tuned circuit. The amplitude of oscillation is varied by varying the coupling of a member to the oscillator tuned circuit responsive to motion. The amplitude of oscillation is monitored and a signal is generated when the amplitude exceeds a predetermined value.
A motion sensing system having an oscillator with a tuned circuit. The amplitude of oscillation is varied by varying the coupling of a member to the oscillator tuned circuit responsive to motion. The amplitude of oscillation is monitored and a signal is generated when the amplitude exceeds a predetermined value.
Description
A-3~724/AJT
~ t599~
MOTION SENSING SYSTEM
This invention relates generally to a motion sensing system and more particularly such a system useful in alarm appli-cations.
In patent 4,205,300 there is described a vehicle anti-theft alarm system. The system includes a plurality of position sensitive switches for sensing motion of the vehicle. Each of said switches has an individual initial state dependent upon the position of the supporting surface for the vehicle and is arranged to change its state from its initial state in response to motion. The switches are respectively either opened or closed in their initial sta'e depending upon the orientation of the vehicle surface and position of the switch. Some of said switches being open in the initial state and others being closed in the initial state.
Switches individually selectively change from the initial state in response to movement of the vehicle. Circuit means are responsive to said switches individually being selec-tively changed from the initial state in response to move-ment of the vehicle for operating an inhibiting or alarmcircuit.
The syst~m is particularly advantageous because it does not require specific orientation of the motion detector. The motion detector can be mounted at any orientation and it is only movement which serves to provide a signal when one or more of the plurality of switches changes its state.
~ ., 1 ~9~25 Mercury switches disposed at different orientations in a switch assembly are described in one embodiment of the patent.
In patent 3,074,049 there is described an alarm system in which a motion sensitive switch is adjustably mounted on a vehicle in a position to be tilted when the vehicle is shaken or tilted. The switch must be acurately positioned so that it is in its open condition to set to alarm. Motion of the vehicle closes the switch and provides the requisite alarm. The requirement of first having to position the switch to set the alarm is a serious drawback of this system.
It is an object of the present invention to provide an improved motion sensing system.
It is another object of the present invention to provide a motion sensing system which can be oriented in any position and which provides an output signal when the system is moved or tilted.
The foregoing and other objects of the invention are achieved by a motion sensing system including a tuned electrical circuit which is driven to oscillate at a frequency de-termined by the circuit components of the oscillator. A
motion responsive means is coupled to the tuned circuit and serves to modulate the amplitude of the oscillations re-sponsive to motion. Means are connected to receive theoscillator signal and provide an output signal when ampli-tude modulation exceeds a predetermined amount. The output signal is used to operate an associated alarm, inhibit or other circuit means.
The foregoing will be more clearly understood from the following description read in connection with the accom-panying drawing.
1 1 5992~
Fi~ure 1 is a block diagram of a motion sensing system in accordance with the present invention;
Fi<~ure 2 shows typical signals on the tuned circuit shown in Figure l;
Figure 3 is a detailed circuit diagram of the system shown in Figure 1.
Referring to Figure 1 the motion sensing system is seen to include a tuned circuit comprising an inductance 11 and a capacitance 12. An amplifier 13 is connected to the tuned circuit to supply power to cause the circuit to oscillate at a predetermined frequency dependent upon the values of the inductance and capacitance. The amplifier circuit, as will be presently described, is a current limited amplifier circuit so that it operates as a current source to supply substantially constant power to the oscillator circuit so that the circuit normally operates at a predetermined amp-litude.
A mercury drop 14 disposed in a glass tube 16 is mounted along the axis of the coil forming the inductor 11. Motion of the tube will cause the mercury drop to move along the tube in and out of the center of the coil where the magnetic field is the strongest. This action introduces variable losses in the tuned circuit and changes the amplitude of the voltages across the tuned circuit. It is clear that
~ t599~
MOTION SENSING SYSTEM
This invention relates generally to a motion sensing system and more particularly such a system useful in alarm appli-cations.
In patent 4,205,300 there is described a vehicle anti-theft alarm system. The system includes a plurality of position sensitive switches for sensing motion of the vehicle. Each of said switches has an individual initial state dependent upon the position of the supporting surface for the vehicle and is arranged to change its state from its initial state in response to motion. The switches are respectively either opened or closed in their initial sta'e depending upon the orientation of the vehicle surface and position of the switch. Some of said switches being open in the initial state and others being closed in the initial state.
Switches individually selectively change from the initial state in response to movement of the vehicle. Circuit means are responsive to said switches individually being selec-tively changed from the initial state in response to move-ment of the vehicle for operating an inhibiting or alarmcircuit.
The syst~m is particularly advantageous because it does not require specific orientation of the motion detector. The motion detector can be mounted at any orientation and it is only movement which serves to provide a signal when one or more of the plurality of switches changes its state.
~ ., 1 ~9~25 Mercury switches disposed at different orientations in a switch assembly are described in one embodiment of the patent.
In patent 3,074,049 there is described an alarm system in which a motion sensitive switch is adjustably mounted on a vehicle in a position to be tilted when the vehicle is shaken or tilted. The switch must be acurately positioned so that it is in its open condition to set to alarm. Motion of the vehicle closes the switch and provides the requisite alarm. The requirement of first having to position the switch to set the alarm is a serious drawback of this system.
It is an object of the present invention to provide an improved motion sensing system.
It is another object of the present invention to provide a motion sensing system which can be oriented in any position and which provides an output signal when the system is moved or tilted.
The foregoing and other objects of the invention are achieved by a motion sensing system including a tuned electrical circuit which is driven to oscillate at a frequency de-termined by the circuit components of the oscillator. A
motion responsive means is coupled to the tuned circuit and serves to modulate the amplitude of the oscillations re-sponsive to motion. Means are connected to receive theoscillator signal and provide an output signal when ampli-tude modulation exceeds a predetermined amount. The output signal is used to operate an associated alarm, inhibit or other circuit means.
The foregoing will be more clearly understood from the following description read in connection with the accom-panying drawing.
1 1 5992~
Fi~ure 1 is a block diagram of a motion sensing system in accordance with the present invention;
Fi<~ure 2 shows typical signals on the tuned circuit shown in Figure l;
Figure 3 is a detailed circuit diagram of the system shown in Figure 1.
Referring to Figure 1 the motion sensing system is seen to include a tuned circuit comprising an inductance 11 and a capacitance 12. An amplifier 13 is connected to the tuned circuit to supply power to cause the circuit to oscillate at a predetermined frequency dependent upon the values of the inductance and capacitance. The amplifier circuit, as will be presently described, is a current limited amplifier circuit so that it operates as a current source to supply substantially constant power to the oscillator circuit so that the circuit normally operates at a predetermined amp-litude.
A mercury drop 14 disposed in a glass tube 16 is mounted along the axis of the coil forming the inductor 11. Motion of the tube will cause the mercury drop to move along the tube in and out of the center of the coil where the magnetic field is the strongest. This action introduces variable losses in the tuned circuit and changes the amplitude of the voltages across the tuned circuit. It is clear that
2~ other movable elements may be used in place of the mercury drop. For example a metal slug mounted on weak springs could be used. Any motion sensitive member which introduces losses to the tuned circuit will suffice. This is illustrated in Figure 2 wherein the normal oscillating amplitude is shown at 17, the oscillations 18 indicated a positioning of the mercury drop to introduce heavy losses and therefore decrease the amplidtude of oscillations whereas the sections 19 shows an increase in amplitude o~ oscillations which occurs when the mercury drop is at its extreme position. Thus, during 1 l~g9~5 normal quiescent operation the oscillations will have one value such as value 17 while with motion the mercury drop will move along the tube 16 and provide both decreased amplitude oscillations such as shown 18 and increased amp-litude oscillations such as shown at 19.
An envelope detector 21 is connected to the oscillator viathe emitter follower 22 so that the envelope detector does not load the tuned circuit. The envelope detector receives the amplitude modulated oscillation and provides a varying direct current (DC) output signal and is capacitively coupled to the DC amplifier 23. The output of the amplifier 23 is a variable voltage which corresponds to the motion of the mercury drop. The varying output voltage from the amplifier 23 is supplied to a level detector 24 which can comprise a pair of comparatos set to high and low limits to accomodate for the swing of the output voltage of the amplifier as indicated by the regions 18 and 19 of Figure 2. When the voltage is outside of this window the circuit considers that motion has occurred and will provide an output signal on the line 26.
The signal can then be employed to drive a suitable alarm 27 such as a horn, lights, etc. or drive an inhibit circuit. If the motion sensing system is used in a vehicle it may drive an anti-theft system such as shown in Patent 4,205,300.
Figure 3 is a detail circuit diagram of one embodiment of the present invention which was constructed and satisfac-torily operated to provide output voltages at 31 which were +12 volts for no motion and 0 volts when the motion detector sensed motion. The component values used in the system are shown on the drawing, Figure 3. The amplifiers UlA, UlB
were LF353. Dual operational amplifiers and U2A, V2B were LM393 compara~ors.
Operational amplifier UlA and associated components form amplifier 13 for driving the tuned circuit comprising the inductor 11 and capacitor 12. The output from the operational amplifier is shown fed to the tuned circuit through resistor Rl to sustain oscillations. The resistor Rl is slelected to 1 1 ~9g?~
--5--make the amplifier look like a current source. The voltage across the coil, being fed by current source decreases as the mercury drop moves closer to the center of the coil when the losses of the tuned circuit is at maximum as illustrated at 18, Figure 2. Although the oscillating frequency of the circuit is not critical in this example it was selected to be about 160 KHz for the convenience of using a reasonable sized component in the associated circuits.
The amplifier UlA operates at its maximum output to provide the constant drive to the circuit.
The transistor 32 is connected as an emitter follower to reduce loading of the tuned circuit and also acts as the envelope detector which provides an output signal having an amplitude corresponding to the envelope of the oscillator signal, Figure 2, for the DC amplifier 23 including UlB
and associated components. The output of this amplifier i5 a slow varying DC voltage about 100 times larger than the output of the envelope detector. The capacitor Cl and resistor 33 provide a feedback circuit for the amplifier 23 so that it does not respond to detector ripple or other interference which might be picked up by the high impedance of the envelope detector. The gain of the amplifier can be adjusted with potentiometer 34.
The output from the amplifier 23 is applied to the level detector 24. The level detector which comprises dual comparators U2A and U2B is connected as a window detector.
In the present example when the voltage output goes below 4.62V or above 7.38V the output comparators are driven to ground potential. In such condition the output line 31 is grounded. This is used to trigger an associated circuit such as an intrusion alarm, light or other associated alarm system.
Thus, it is seen that there has been provided a simple motion detector which operates independently of the quiescent position of the alarm motion detector (mercury drop) and which provides an output when there is motion.
An envelope detector 21 is connected to the oscillator viathe emitter follower 22 so that the envelope detector does not load the tuned circuit. The envelope detector receives the amplitude modulated oscillation and provides a varying direct current (DC) output signal and is capacitively coupled to the DC amplifier 23. The output of the amplifier 23 is a variable voltage which corresponds to the motion of the mercury drop. The varying output voltage from the amplifier 23 is supplied to a level detector 24 which can comprise a pair of comparatos set to high and low limits to accomodate for the swing of the output voltage of the amplifier as indicated by the regions 18 and 19 of Figure 2. When the voltage is outside of this window the circuit considers that motion has occurred and will provide an output signal on the line 26.
The signal can then be employed to drive a suitable alarm 27 such as a horn, lights, etc. or drive an inhibit circuit. If the motion sensing system is used in a vehicle it may drive an anti-theft system such as shown in Patent 4,205,300.
Figure 3 is a detail circuit diagram of one embodiment of the present invention which was constructed and satisfac-torily operated to provide output voltages at 31 which were +12 volts for no motion and 0 volts when the motion detector sensed motion. The component values used in the system are shown on the drawing, Figure 3. The amplifiers UlA, UlB
were LF353. Dual operational amplifiers and U2A, V2B were LM393 compara~ors.
Operational amplifier UlA and associated components form amplifier 13 for driving the tuned circuit comprising the inductor 11 and capacitor 12. The output from the operational amplifier is shown fed to the tuned circuit through resistor Rl to sustain oscillations. The resistor Rl is slelected to 1 1 ~9g?~
--5--make the amplifier look like a current source. The voltage across the coil, being fed by current source decreases as the mercury drop moves closer to the center of the coil when the losses of the tuned circuit is at maximum as illustrated at 18, Figure 2. Although the oscillating frequency of the circuit is not critical in this example it was selected to be about 160 KHz for the convenience of using a reasonable sized component in the associated circuits.
The amplifier UlA operates at its maximum output to provide the constant drive to the circuit.
The transistor 32 is connected as an emitter follower to reduce loading of the tuned circuit and also acts as the envelope detector which provides an output signal having an amplitude corresponding to the envelope of the oscillator signal, Figure 2, for the DC amplifier 23 including UlB
and associated components. The output of this amplifier i5 a slow varying DC voltage about 100 times larger than the output of the envelope detector. The capacitor Cl and resistor 33 provide a feedback circuit for the amplifier 23 so that it does not respond to detector ripple or other interference which might be picked up by the high impedance of the envelope detector. The gain of the amplifier can be adjusted with potentiometer 34.
The output from the amplifier 23 is applied to the level detector 24. The level detector which comprises dual comparators U2A and U2B is connected as a window detector.
In the present example when the voltage output goes below 4.62V or above 7.38V the output comparators are driven to ground potential. In such condition the output line 31 is grounded. This is used to trigger an associated circuit such as an intrusion alarm, light or other associated alarm system.
Thus, it is seen that there has been provided a simple motion detector which operates independently of the quiescent position of the alarm motion detector (mercury drop) and which provides an output when there is motion.
Claims (7)
1. Apparatus for detecting motion of an object on which it is placed comprising:
an oscillator including a tuned circuit providing oscillations, motion responsive means in said apparatus coupled to said tuned circuit and serving to move and modulate the amplitude of the oscillations of said oscillator responsive to motion of the object, and means connected to said oscillator to receive the oscillations and provide an output signal when the amplitude modulation of the oscillations exceeds a predetermined amount.
an oscillator including a tuned circuit providing oscillations, motion responsive means in said apparatus coupled to said tuned circuit and serving to move and modulate the amplitude of the oscillations of said oscillator responsive to motion of the object, and means connected to said oscillator to receive the oscillations and provide an output signal when the amplitude modulation of the oscillations exceeds a predetermined amount.
2. An apparatus as in Claim 1 in which said oscillator includes a current limited amplifier connected to said tuned circuit.
3. An apparatus as in Claim 1 in which said tuned circuit includes an inductance and said motion responsive means is coupled to said inductance to introduce losses into said tuned circuit.
4. An apparatus as in Claim 2 in which said tuned circuit includes an inductance and said motion responsive means is coupled to said inductance to introduce losses into said tuned circuit.
5. An apparatus for detecting motion of an object on which it is placed comprising:
an oscillator including a tuned circuit providing output oscillations, motion responsive means in said apparatus coupled to said tuned circuit to move and modulate the amplitude of the oscillations responsive to motion of the object, an envelope detector connected to said oscillator to receive the oscillations and provide an output signal whose amplitude is representative of the amplitude of the oscillations, means for receiving said output signal and provide an alarm signal when the amplitude of said output signal falls outside a predetermined upper or lower level.
an oscillator including a tuned circuit providing output oscillations, motion responsive means in said apparatus coupled to said tuned circuit to move and modulate the amplitude of the oscillations responsive to motion of the object, an envelope detector connected to said oscillator to receive the oscillations and provide an output signal whose amplitude is representative of the amplitude of the oscillations, means for receiving said output signal and provide an alarm signal when the amplitude of said output signal falls outside a predetermined upper or lower level.
6. An apparatus as in Claim 5 in which said oscillator includes a current limited amplified connected to said tuned circuit.
7. An apparatus as in Claim 6 in which said tuned circuit includes an inductance and said motion responsive means is coupled to said inductance to introduce losses into said tuned circuit.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/268,569 US4414541A (en) | 1981-05-29 | 1981-05-29 | Motion sensing system |
US268,569 | 1981-05-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1159925A true CA1159925A (en) | 1984-01-03 |
Family
ID=23023574
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000403767A Expired CA1159925A (en) | 1981-05-29 | 1982-05-26 | Motion sensing system |
Country Status (4)
Country | Link |
---|---|
US (1) | US4414541A (en) |
JP (1) | JPS5829089A (en) |
CA (1) | CA1159925A (en) |
DE (1) | DE3220068A1 (en) |
Families Citing this family (37)
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US4492952A (en) * | 1982-04-12 | 1985-01-08 | Atlas Electronics International | Automotive driving condition alarm system |
IT1192486B (en) * | 1982-07-27 | 1988-04-13 | Pierluigi Floris | SYSTEM FOR TRANSFORMING THE MOVEMENTS OF A MASS OF MERCURY INTO ELECTRICAL SIGNALS, FOR MEASURING EQUIPMENT AND OTHER |
US5224385A (en) * | 1982-07-27 | 1993-07-06 | Floris Pierluigi | Method for obtaining electrical signals correlated with the position of a mass of mercury in instruments and the like |
DE3318275C2 (en) * | 1983-05-17 | 1992-05-07 | f + g megamos Sicherheitselektronik GmbH, 5250 Engelskirchen | Method for monitoring the inclination of a motor vehicle |
US4678992A (en) * | 1983-07-12 | 1987-07-07 | Hi-Tech Systems, Corp. | Electronic metal detector |
US4598260A (en) * | 1984-04-18 | 1986-07-01 | Transducer Limited Partnership | Eddy current proximeter |
US4673854A (en) * | 1984-08-01 | 1987-06-16 | Southern Railway Company | Electronic cross-level detection system |
US4956606A (en) * | 1984-10-17 | 1990-09-11 | Mine Safety Appliances Company | Non-contact inductive distance measuring system with temperature compensation |
DE3438120A1 (en) * | 1984-10-18 | 1986-04-24 | Gebhard Balluff Fabrik feinmechanischer Erzeugnisse GmbH & Co, 7303 Neuhausen | INTERFERENCE FIELD DETECTOR |
US4684928A (en) * | 1984-12-03 | 1987-08-04 | Alpine Electronics Inc. | Motion sensor unit |
US4742338A (en) * | 1985-05-17 | 1988-05-03 | Gec Avionics Limited | Intruder alarm system |
US4796013A (en) * | 1985-10-18 | 1989-01-03 | Aisin Seiki Kabushiki Kaisha | Capacitive occupancy detector apparatus |
US4831279A (en) * | 1986-09-29 | 1989-05-16 | Nartron Corporation | Capacity responsive control circuit |
US5117217A (en) * | 1987-01-21 | 1992-05-26 | Electronic Security Products Of California | Alarm system for sensing and vocally warning a person to step back from a protected object |
US5315285A (en) * | 1987-01-21 | 1994-05-24 | Electronic Security Products Of California, Inc. | Alarm system for sensing and vocally warning a person approaching a protected object |
US4755806A (en) * | 1987-03-09 | 1988-07-05 | Villarreal Juan M | Movement sensor |
US4866417A (en) * | 1987-04-24 | 1989-09-12 | Specific Cruise Systems, Inc. | Automobile intruder alarm system |
US5079538A (en) * | 1987-04-24 | 1992-01-07 | Specific Cruise Systems, Inc. | Automobile intruder alarm system |
US4899133A (en) * | 1988-02-08 | 1990-02-06 | Detex Corporation | Programmable movement analyzer with a plurality of mercury switches |
DE3825298A1 (en) * | 1988-07-26 | 1990-02-01 | Rolf Neusel | Method and arrangement of a sensor for multidimensional movement and vibration, preferably in the case of low signal strength |
US5081406A (en) * | 1990-06-26 | 1992-01-14 | Saf-T-Margin, Inc. | Proximity responsive capacitance sensitive method, system, and associated electrical circuitry for use in controlling mechanical and electro-mechanical equipment |
DE4320188A1 (en) * | 1993-06-18 | 1994-12-22 | Marian Siegmueller | Method for securing a motor vehicle against being driven away without authorisation |
DE4335773C2 (en) * | 1993-10-20 | 2000-07-27 | Mader Elektronik Und Telekommu | motion detector |
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US5654688A (en) * | 1995-04-14 | 1997-08-05 | Omega Research And Development, Inc. | Vehicle security system having enhanced remote transmitter security |
US6140938A (en) | 1995-04-14 | 2000-10-31 | Flick; Kenneth E. | Remote control system suitable for a vehicle and having remote transmitter verification |
US5663704A (en) * | 1995-04-14 | 1997-09-02 | Kenneth E. Flick | Vehicle security system having enhanced door locking features |
US5612669A (en) * | 1995-04-14 | 1997-03-18 | Kenneth E. Flick | Vehicle security system having enhanced false alarm compensation |
US7737820B2 (en) * | 1995-04-14 | 2010-06-15 | Omega Patents, L.L.C. | Remote control system for an access door having remote transmitter verification |
US5729191A (en) * | 1995-04-14 | 1998-03-17 | Kenneth E. Flick | Vehicle security system having enhanced control features |
US6480095B1 (en) | 1995-04-14 | 2002-11-12 | Omega Patents, L.L.C. | Vehicle control system including multi-digit control switch and associated methods |
US5654686A (en) * | 1995-07-26 | 1997-08-05 | Prince Corporation | Electronic vehicle theft detection system employing a magnetic field sensor |
IL135730A (en) * | 2000-04-18 | 2004-05-12 | Visonic Ltd | Displacement sensing system |
US6682371B2 (en) | 2000-07-06 | 2004-01-27 | Louis P. Steinhauser | Outboard motor position responsive system |
US6447347B1 (en) | 2000-07-06 | 2002-09-10 | Louis P. Steinhauser | Trolling motor position responsive system |
US20100090816A1 (en) * | 2008-08-08 | 2010-04-15 | Dick Hirsch | Computer Screen Blanking Systems |
EP2497670B1 (en) * | 2011-03-11 | 2015-07-01 | Johnson Controls Automotive Electronics GmbH | Method and apparatus for monitoring the alertness of the driver of a vehicle |
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US3074049A (en) * | 1963-01-15 | Alarm system for motor vehicles | ||
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US2154260A (en) * | 1934-05-12 | 1939-04-11 | Westinghouse Electric & Mfg Co | Electronic metering system |
US3602806A (en) * | 1969-02-12 | 1971-08-31 | Jan A Czekajewski | Selective activity meter for laboratory animals |
US3658052A (en) * | 1970-06-16 | 1972-04-25 | American Electronic Lab | Breathing activity monitoring and alarm device |
US3747012A (en) * | 1972-09-21 | 1973-07-17 | R Buck | Contactless oscillator-type proximity sensor with adjustable hysteresis |
US4164075A (en) * | 1974-01-07 | 1979-08-14 | Capitol Records, Inc. | Phonograph record eccentricity tester |
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FR2336278A1 (en) * | 1975-12-23 | 1977-07-22 | Maillot Jean | ELECTROMAGNETIC DEVICE FOR VIBRATION DETECTOR, ESPECIALLY FOR ANTI-THEFT |
FR2336750A1 (en) * | 1975-12-23 | 1977-07-22 | Maillot Jean | DETECTOR DEVICE, AND IN PARTICULAR ANTI-THEFT DEVICE |
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US4053849A (en) * | 1976-10-01 | 1977-10-11 | Systron Donner Corporation | Oscillation means for generating a differential AC signal proportional to movement of a conducting member |
JPS5435147U (en) * | 1977-08-12 | 1979-03-07 | ||
FR2420119A1 (en) * | 1978-03-17 | 1979-10-12 | Telemecanique Electrique | INDUCTIVE PROXIMITY SENSOR PROVIDING AN OUTPUT SIGNAL PROPORTIONAL TO THE DISTANCE |
US4286261A (en) * | 1978-09-01 | 1981-08-25 | The United States Of America As Represented By The Secretary Of The Army | Apparatus for discriminating between strain and magnetic stimuli in magnetic cored solenoid type transducer line sensors |
DE2852246C2 (en) * | 1978-12-02 | 1984-01-26 | Securiton AG, 3052 Zollikofen, Bern | Electrical device for protecting movable objects |
-
1981
- 1981-05-29 US US06/268,569 patent/US4414541A/en not_active Expired - Lifetime
-
1982
- 1982-05-26 CA CA000403767A patent/CA1159925A/en not_active Expired
- 1982-05-27 JP JP57090472A patent/JPS5829089A/en active Granted
- 1982-05-27 DE DE19823220068 patent/DE3220068A1/en active Granted
Also Published As
Publication number | Publication date |
---|---|
DE3220068A1 (en) | 1982-12-23 |
US4414541A (en) | 1983-11-08 |
JPH0418359B2 (en) | 1992-03-27 |
DE3220068C2 (en) | 1992-01-16 |
JPS5829089A (en) | 1983-02-21 |
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