DE3013770C2 - - Google Patents
Info
- Publication number
- DE3013770C2 DE3013770C2 DE3013770A DE3013770A DE3013770C2 DE 3013770 C2 DE3013770 C2 DE 3013770C2 DE 3013770 A DE3013770 A DE 3013770A DE 3013770 A DE3013770 A DE 3013770A DE 3013770 C2 DE3013770 C2 DE 3013770C2
- Authority
- DE
- Germany
- Prior art keywords
- tongue
- fet structure
- resonant
- output signal
- frequency
- 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
- 238000002485 combustion reaction Methods 0.000 claims description 9
- 230000010287 polarization Effects 0.000 claims description 3
- 238000013016 damping Methods 0.000 claims description 2
- 230000005669 field effect Effects 0.000 claims description 2
- 239000003990 capacitor Substances 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/12—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by alteration of electrical resistance
- G01P15/124—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by alteration of electrical resistance by semiconductor devices comprising at least one PN junction, e.g. transistors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L23/00—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid
- G01L23/22—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines
- G01L23/221—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines for detecting or indicating knocks in internal combustion engines
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/125—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by capacitive pick-up
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P2015/0805—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration
- G01P2015/0822—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass
- G01P2015/0825—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass for one single degree of freedom of movement of the mass
- G01P2015/0828—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass for one single degree of freedom of movement of the mass the mass being of the paddle type being suspended at one of its longitudinal ends
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
- Measuring Fluid Pressure (AREA)
Description
Die Erfindung betrifft einen Sensor nach dem Oberbegriff des Patent anspruchs 1.The invention relates to a sensor according to the preamble of the patent claim 1.
Es ist bekannt, daß bei Brennkraftmaschinen unter bestimmten Ar beitsbedingungen ein sogenanntes Klopfen auftritt. Hierunter versteht man tonfrequente Schwingungen des komprimierten Kraftstoff-Luft-Gemisches, die durch eine Stoßwelle ausgelöst werden. Während dieser Schwingungen ist der Wärmeübergang an Kolben und Zylinderwänden der Brennkraftmaschine stark überhöht. Dies bedingt eine schädliche thermische Überlastung dieser Flächen, so daß das Klopfen grundsätzlich zu vermeiden ist. Da man jedoch andererseits bestrebt ist, den bestehenden Arbeitsbereich der Brennkraftmaschine möglichst weitgehend auszunützen, besteht Interesse an einem Sensor, der das Klopfen frühzeitig und sicher anzeigt.It is known that in internal combustion engines under certain Ar conditions known as knocking occurs. Below one understands sound-frequency vibrations of the compressed Air-fuel mixture triggered by a shock wave will. During these vibrations, the heat is transferred to the piston and cylinder walls of the internal combustion engine greatly increased. This causes a damaging thermal overload of these areas, so that knocking should be avoided. However, since one on the other hand, the existing work area of the To utilize the internal combustion engine as much as possible exists Interested in a sensor that detects knocking early and safely displays.
Bekannte Sensoren zu diesem Zweck sind piezoelektrische Druckindikatoren, die in eine besondere Bohrung im Zylinderkopf einer Brennkraftmaschine eingeschraubt werden und mit dem Innenraum des Zylinders der Brennkraftmaschine in Verbindung stehen. Eine der artige Befestigungsart ist jedoch außerordentlich aufwendig und teuer.Known sensors for this purpose are piezoelectric Pressure indicators in a special hole in the cylinder head be screwed into an internal combustion engine and with the interior of the cylinder of the internal combustion engine are connected. One of the type of attachment is extremely complex and expensive.
Aus dem Buch von Hans R. Camenzind, "Circuit Design for Integrated Electronics", Addision-Wesley Publishing Company, 1968, ist ein Resonanzelement bekannt, das aus einer resonanzfähigen Zunge besteht, die über einem Kanal einer FET-Struktur angeordnet ist. From the book by Hans R. Camenzind, "Circuit Design for Integrated Electronics ", Addision-Wesley Publishing Company, 1968, is a Resonance element known from a resonant tongue exists, which is arranged over a channel of an FET structure.
Aus der DE-OS 28 01 969 ist des weiteren bereits ein Sensor nach dem Oberbegriff des Patentanspruchs 1 bekannt, bei dem das Resonanz element als piezoelektrisches Element ausgebildet ist. Das elektrische Ausgangssignal wird hierbei an zwei metallischen Belägen abgenommen, die an den beiden freien Flächen der resonanzfähigen Zunge des piezoelektrischen Elements angebracht sind. Dieser be kannte Sensor hat jedoch den Nachteil, daß er als diskretes Bau element ausgebildet ist und nicht Bestandteil einer monolitisch integrierten Schaltung sein kann. Ein weiterer Nachteil besteht darin, daß das elektrische Ausgangssignal des piezoelektrischen Elements nicht mit einer weiteren Frequenz modulierbar ist, so daß eine Auswertung des Ausgangssignals im Trägerfrequenzverfahren bei dem bekannten Sensor nicht möglich ist.From DE-OS 28 01 969 is also a sensor according to the The preamble of claim 1 is known, in which the resonance element is designed as a piezoelectric element. The electrical output signal is here on two metallic pads removed that on the two free surfaces of the resonant Tongue of the piezoelectric element are attached. This be Known sensor has the disadvantage that it is a discrete construction element is formed and not part of a monolithic integrated circuit can be. Another disadvantage is in that the electrical output signal of the piezoelectric Elements cannot be modulated with another frequency, so that an evaluation of the output signal using the carrier frequency method the known sensor is not possible.
Aus der US-PS 34 13 573 ist des weiteren bereits ein als Feldeffektransistor-Resonator ausgebildetes Resonanzelement bekannt, bei dem ein resonanzfähiges, als Stab ausgebildetes Glied über einem Kanal einer FET-Struktur angeodnet ist. Das elektrische Ausgangssignal der FET-Struktur ist hierbei über eine zusätzliche Elektrode modulierbar, die sich außerhalb der FET-Struktur befindet und auf das resonanzfähige Glied einwirkt.From US-PS 34 13 573 is also already a Field effect transistor resonator designed resonance element is known in which a resonant member designed as a rod is arranged over a channel of an FET structure. The electrical The output signal of the FET structure is an additional one Modular electrode that is located outside the FET structure and acts on the resonable member.
In der DE-Patentanmeldung P 28 29 246 wurde des weiteren eine Ein
richtung zur Erfassung der beim Klopfen einer Brennkraftmaschine
auftretenden Schwingungen vorgeschlagen, bei der ein
piezoelektrischer Biegeschwinger als Resonanzelement dient. Auch
dieser Sensor hat den Nachteil, daß er als diskretes Bauelement aus
gebildet ist und nicht Bestandteil einer monolitisch integrierten
Schaltung sein kann.
In DE patent application P 28 29 246, a device for detecting the vibrations occurring when knocking an internal combustion engine was further proposed, in which a piezoelectric bending oscillator serves as a resonance element. This sensor also has the disadvantage that it is formed as a discrete component and cannot be part of a monolithically integrated circuit.
Der Erfindung liegt die Aufgabe zugrunde, einen Sensor nach dem Oberbegriff des Patentanspruchs 1 derart auszubilden, daß er Be standteil einer monolitisch integrierten Schaltung sein kann, und gleichzeitig Mittel vorzusehen, durch die das elektrische Ausgangs signal des Resonanzelements mit einer Frequenz modulierbar ist, die wesentlich höher als die Klopffrequenz liegt.The invention has for its object a sensor according to The preamble of claim 1 form such that he Be can be part of a monolithically integrated circuit, and at the same time to provide means through which the electrical output Signal of the resonance element can be modulated with a frequency that is significantly higher than the knock frequency.
Erfindungsgemäß ist diese Aufgabe durch die kennzeichnenden Merkmale des Patentanspruchs 1 gelöst. Weitere Vorteile der Erfindung ergeben sich aus dem Unteranspruch 2.According to the invention, this object is achieved by the characteristic features of claim 1 solved. Further advantages of the invention result themselves from subclaim 2.
Ein Ausführungsbeispiel eines erfindungsgemäßen Sensors wird anhand von Figuren in der nachfolgenden Beschreibung näher erläutert. Es zeigtAn embodiment of a sensor according to the invention is based on of figures explained in more detail in the following description. It shows
Fig. 1 eine perspektivische Ansicht eines Resonanzelementes; Fig. 1 is a perspective view of a resonance element;
Fig. 2 eine Draufsicht der in Fig. 1 dargestellten Anordnung. Fig. 2 is a plan view of the arrangement shown in Fig. 1.
Bei dem in Fig. 1 dargestellten Resonanzelement ist auf einem Substrat 10 vermittels eines Fußteiles 11 eine resonanzfähige Zunge 12 befestigt, die über einem Kanal 13, der ein Gate einer FET-Struktur bildet, angeordnet ist. In the resonance element shown in FIG. 1, a resonant tongue 12 is fastened on a substrate 10 by means of a foot part 11 and is arranged above a channel 13 , which forms a gate of an FET structure.
Die FET-Struktur 14 weist weiterhin eine Source-Elektrode 15 und eine Drain-Elektrode 16 auf. Unter dem freien Ende der Zunge 12 ist eine Elektrodenplatte 17 angeordnet, die mit einer Spannungsquelle 18 verbunden ist. Die Drain-Elektrode 16 ist weiterhin an eine Gleichspannungsquelle 19 und über einen Koppelkondensator 20 an eine Klemme 21 angeschlossen.The FET structure 14 also has a source electrode 15 and a drain electrode 16 . An electrode plate 17 , which is connected to a voltage source 18 , is arranged under the free end of the tongue 12 . The drain electrode 16 is also connected to a direct voltage source 19 and to a terminal 21 via a coupling capacitor 20 .
Die in Fig. 1 dargestellte Anordnung bildet ein resonantes System, wobei die Resonanzfrequenz der Zunge 12 in bekannter Weise von ihrer Länge, Breite, von der Dichte des verwendeten Materiales und vom Elastizitätsmodul des Materiales abhängt. Wird die Anordnung ent sprechend Fig. 1 nun mit einem schwingungsfähigen Teil der Brenn kraftmaschine verbunden und ist die Resonanzfrequenz der Zunge 12 so eingestellt, daß sie der Klopffrequenz der jeweiligen Brennkraft maschine entspricht, entsteht beim Klopfen der Brennkraftmaschine eine resonante Schwingung der Zunge 12. Diese Resonanzerscheinung wirkt sich über den Kanal 13 auf die FET-Struktur aus, die im Takt der Schwingungsbewegung der Zunge 12 moduliert wird. Das Resonanz signal ließe sich nun bereits über den Koppelkondensator 20 und die Klemme 21 abgreifen und weiterverarbeiten.The arrangement shown in FIG. 1 forms a resonant system, the resonance frequency of the tongue 12 depending in a known manner on its length, width, on the density of the material used and on the modulus of elasticity of the material. If the arrangement is accordingly Fig. 1 now with a vibratory portion of the engine is connected and the resonant frequency of the tongue 12 is adjusted so that it corresponds to the knock frequency of the respective internal combustion engine, when knocking of the internal combustion engine results in a resonant vibration of the tongue 12. This resonance phenomenon affects the FET structure via the channel 13 , which is modulated in time with the oscillating movement of the tongue 12 . The resonance signal could now be tapped and further processed via the coupling capacitor 20 and the terminal 21 .
Nach Fig. 2 ist jedoch vorgesehen, daß die FET-Struktur 14 eine weitere Gate-Elektrode 22 aufweist, die von einem Hochfrequenz generator 23 gespeist wird. Durch Einspeisung des Hochfrequenz signales aus dem Hochfrequenzgenerator 23 ist eine Messung der Resonanz im Trägerfrequenzverfahren möglich, wenn die Frequenz des Hochfrequenzgenerators 23 wesentlich höher liegt als die Resonanz frequenz der Zunge 12. Auf diese Weise ist es möglich, bereits am Meßort den Meßwert in einen Frequenzbereich umzusetzen, der frei von den im Kraftfahrzeug üblichen Störsignalen ist. FIG. 2 is provided, however, that the FET structure 14 has a further gate electrode 22, which is powered by a high frequency generator 23. By feeding the high frequency signal from the high frequency generator 23, a measurement of the resonance frequency in the carrier process is possible when the frequency of the high frequency generator 23 is considerably higher than the resonance frequency of the tongue 12th In this way, it is possible to convert the measured value into a frequency range that is free of the interference signals that are customary in motor vehicles.
Will man die Resonanz der Zunge 12 in definierter Weise bedämpfen, kann man sich hierzu der Elektrodenplatte 17 bedienen. Über die Spannungsquelle 18 wird hierzu eine Polarisationsspannung zwischen die Zunge 12 und die Elektrodenplatte 17 gelegt, so daß sich zwischen dem freien Ende der Zunge 12 und der Elektrodenplatte 17 ein elektrisches Feld ausbildet. Die durch Anlegung einer konstanten Polarisationsspannung auftretende Kraft zwischen dem freien Ende der Zunge 12 und der Elektrodenplatte 17 bewirkt dabei die gewünschte Dämpfung der Zunge 12.If you want to dampen the resonance of the tongue 12 in a defined manner, the electrode plate 17 can be used for this. For this purpose, a polarization voltage is applied between the tongue 12 and the electrode plate 17 via the voltage source 18 , so that an electric field is formed between the free end of the tongue 12 and the electrode plate 17 . The force occurring between the free end of the tongue 12 and the electrode plate 17 by applying a constant polarization voltage brings about the desired damping of the tongue 12 .
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19803013770 DE3013770A1 (en) | 1980-04-10 | 1980-04-10 | Knock vibration detector for IC engines - has externally attached FET resonator with damping polarisation voltage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19803013770 DE3013770A1 (en) | 1980-04-10 | 1980-04-10 | Knock vibration detector for IC engines - has externally attached FET resonator with damping polarisation voltage |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| DE3013770A1 DE3013770A1 (en) | 1981-10-29 |
| DE3013770C2 true DE3013770C2 (en) | 1989-11-30 |
Family
ID=6099656
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE19803013770 Granted DE3013770A1 (en) | 1980-04-10 | 1980-04-10 | Knock vibration detector for IC engines - has externally attached FET resonator with damping polarisation voltage |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE3013770A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2578323B1 (en) * | 1985-03-01 | 1987-11-20 | Metravib Sa | INTEGRATED SENSOR OF MECHANICAL QUANTITIES WITH CAPACITIVE EFFECT AND MANUFACTURING METHOD. |
| DE3515349A1 (en) * | 1985-04-27 | 1986-10-30 | Messerschmitt-Bölkow-Blohm GmbH, 8012 Ottobrunn | ELECTRICAL TRANSMITTER FOR MEASURING MECHANICAL SIZES |
| FR2599833B1 (en) * | 1986-06-10 | 1992-02-14 | Metravib Sa | INTEGRATED MECHANICAL SENSOR ON SILICON AND MANUFACTURING METHOD |
| US5070843A (en) * | 1989-05-15 | 1991-12-10 | Mitsubishi Denki Kabushiki Kaisha | Ignition timing control apparatus of internal-combustion engine |
| EP0826967A1 (en) * | 1996-09-02 | 1998-03-04 | STMicroelectronics S.r.l. | Semiconductor acceleration sensor |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3413573A (en) * | 1965-06-18 | 1968-11-26 | Westinghouse Electric Corp | Microelectronic frequency selective apparatus with vibratory member and means responsive thereto |
| DE2801969C2 (en) * | 1978-01-18 | 1982-11-04 | Robert Bosch Gmbh, 7000 Stuttgart | Sensor for vibrations |
| DE2829246A1 (en) * | 1978-07-04 | 1980-01-17 | Bosch Gmbh Robert | IC engine knocking oscillation detector - has piezoelectric oscillator connected to pulse width modulator |
-
1980
- 1980-04-10 DE DE19803013770 patent/DE3013770A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE3013770A1 (en) | 1981-10-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE4118793C2 (en) | Device for determining and / or monitoring a predetermined fill level in a container | |
| EP0449023B1 (en) | Device for determining and/or monitoring a predetermined filling level in a container | |
| DE2801969C2 (en) | Sensor for vibrations | |
| EP0925617B1 (en) | Transition from a waveguide to a strip transmission line | |
| DE3878473T3 (en) | Liquid converter. | |
| EP0734532B1 (en) | Rotation speed sensor | |
| DE3828591C2 (en) | Injection valve for internal combustion engines | |
| DE3930314A1 (en) | PIEZOELECTRIC SENSOR FOR MONITORING A KINETIC MOTION SIZE | |
| DE2906407C2 (en) | Piezoelectric transducer element for installation in pressure, force or acceleration sensors | |
| DE1572996B2 (en) | Monolithic, electromechanical oscillator | |
| DE112004002297T5 (en) | Pressure sensor device | |
| DE3026114A1 (en) | DEVICE FOR VIBRATION ISOLATION OF THE DRIVER'S CAB | |
| DE69930652T2 (en) | MONOLITHIC MINIATURE ACCELERATION SENSOR | |
| EP0140066A1 (en) | Device for detecting forces, tensions or accelerations at machines, apparatuses or the like | |
| DE3013770C2 (en) | ||
| EP0769683A2 (en) | System for monitoring a predetermined level of a fluid in a container | |
| DE3844354A1 (en) | MEASURING DEVICE FOR MEASURING THE MASS OF A FLOWING MEDIUM | |
| DE4201360C2 (en) | Level measuring device | |
| DE3201755C2 (en) | Piezoelectric knock sensor for internal combustion engines | |
| DE10058986A1 (en) | Impact sound sensor device for use in a motor vehicle has an oscillating weight to operate with a piezo element and a printed circuit board. | |
| DE4401313B4 (en) | Piezoelectric, resonant knock sensor for an internal combustion engine | |
| DE2241542A1 (en) | DEVICE WITH CAVITY RESONATORS | |
| DE10255609A1 (en) | Vibrating gyroscope and electronic device using the same | |
| DE3808481A1 (en) | Device for the determination of a specific level in a container | |
| DE19639075A1 (en) | Fastening device for a sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 8110 | Request for examination paragraph 44 | ||
| D2 | Grant after examination | ||
| 8364 | No opposition during term of opposition | ||
| 8339 | Ceased/non-payment of the annual fee |