摘要:
A liquid container hydrostatic level gauge, in particular a fuel tank level indicator, which operates with a differential pressure sensor, a zero point calibration related to the height of the fuel is performed upon the beginning of measurement, in order to dispense with a requirement for temperature independence and long-term stability of the zero point of the differential pressure sensor. A meter tube is disposed in the container interior, extending from above the maximum liquid level to as far as the container bottom with an opening for receiving fuel within the tank. The differential pressure sensor is connected by one meter input to the upper end of the meter tube and by its other meter input is exposed to the air pressure acting upon the surface of the liquid. An air pump is connected to the upper end of the meter tube between the upper level of the fuel and the input to the pressure sensor. At the beginning of measurement, the meter tube is flooded, and an output value (U.sub.o) of the differential pressure sensor is stored in memory. For determining the fill level, the meter fuel is forced from the tube by pumping air in, and the fill level (h(t)) is determined from a measure of the difference between the instantaneous output signal (u(t)) and the memorized value (U.sub.o).
摘要:
The apparatus for determining rotational position of a rotatable element without contacting it includes a sensor device having two Hall or AMR sensor elements for sensing a magnetic field of magnetic field strength (B) generated by or influenced by the rotational position of the rotatable element and for producing output signals according to the magnetic field and thus the rotational position of the rotatable element. In order to easily detect the absolute rotational position of the rotatable element, the sensor device is constructed and positioned with respect to the rotatable element so that in every rotational position the field lines from the rotatable element extend at right angles to the sensor structures defined by the direction of an alternating current in the sensor elements. Using different embodiments of an electronic evaluation circuit, the direction components of the magnetic field are evaluated to determine the rotational position by comparing the input current to one of the sensors and the sum of the output signals of the respective sensor elements. Either sinusoidal or rectangular alternating voltages or direct voltages are input to the sensor elements.
摘要:
In an arrangement that can be implemented with a simple circuit, the load is connected in parallel to an additional resistor. The primary-side input resistance of the transformer is measured, and when the input resistance differs from a predefined value, a load malfunction is signaled.
摘要:
A synchronous rectifier, to which the primary-side input voltage of the transformer and a control voltage with the same frequency as the input voltage is applied, is connected to the primary side of the transformer. The phase of the control voltage can be switched between 0.degree. and 90.degree., so that the output voltage of the synchronous rectifier corresponds exclusively to the voltage drop component at the ohmic input resistance of the transformer at 0.degree., and exclusively to the voltage drop component at the inductive input resistance of the transformer at 90.degree.. Since both the ohmic and the inductive input resistances are dependent on the resistance of the load connected to the secondary side (e.g., the squib of an air bag), both voltage components can be used to obtain reliable information on the status of the load resistance.
摘要:
A pressure pickup for measuring the pressure in the intake manifold of an internal combustion engine. The pressure pickup comprises a part, movable in response to the manifold pressure, to which is coupled means for short-circuiting the magnetic flux lines of an electromagnet so that the change in flux lines is detected by the electromagnetic coil and measured by an induction evaluation circuit and thus indirectly measuring the manifold pressure.
摘要:
In order that a signal can be transmitted without contact from a stationary vehicle part to a rotationally mounted vehicle part, in the case of axial displacement between the parts, provision is made for a rotary transformer having pot-type cores for primary and secondary windings which have L-shaped profiles. These pot-type cores are mounted coaxially inside each other such that one or a plurality of air gaps existing between them run parallel to the rotational axis and are intersected by the magnetic flux radially with respect to the rotational axis. One of the surfaces of the two pot-type cores bordering on the air gaps is provided with a bevel, which tends to decrease the width of the air gap when an axial displacement lengthens the path of the magnetic flux. One of the pot-type cores may include a plurality of ring segments.
摘要:
A circuit arrangement for transmitting variable measurement values, such as pressure and temperature, at vehicle wheels is provided which transmits the measurement values in the form of H-F signals to a stationary evaluating circuit (12) with great accuracy, high reliability and in short time intervals. A repeater coil (b 13), which is connected with the latter, arranged in the vicinity of the wheel so as to be stationary and connected to voltage by a square-wave generator (15), cooperates with a revolving repeated coil (19) which is fastened at the vehicle wheel and connected with a sensor circuit arrangement (20) supplied by it. The sensor circuit arrangement (20) contains a timing element (29) which responds to a voltage peak in the revolving repeater coil (19 l) at the end of a voltage pulse of the square-wave generator (15) and, with a corresponding delay, triggers a timing circuit (30) for transmitting the measurement values, which timing circuit (30) is connected with it on the output side, wherein the delay time of the timing element (29), together with the duty cycle of the timing circuit (30), is shorter than the pause time of the square-wave voltage at the square-wave generator (15).
摘要:
The arrangement includes a transformer whose primary winding and secondary winding are in separate pot cores which can rotate in opposite directions about the axis of rotation of the steering wheel. To prevent these transformers from transferring energy to the squib which could deploy the air bag when a short-circuit to lines carrying on-board voltage occurs on its primary side, only one of the two pot cores is designed as a closed ring and the other pot core is made of one or more ring segments.
摘要:
An arrangement allowing a definite and reliable determination of a load resistance connected to the secondary side of a transformer includes devices, which measure exclusively the inductance of the transformer on the primary side and signal a load malfunction in the case of deviation from a predefined value.
摘要:
An arrangement for contactless transmission of signals, e.g., between at least one circuit unit installed on the vehicle body and at least one circuit unit in a vehicle seat mounted displaceably on rails is described. This arrangement is free of wear and guarantees interference-free signal transmission. This arrangement consists of at least one repeating coil whose primary winding and secondary winding are in separate pot-type cores, one of which is mounted on a stationary vehicle part (body) and the other is mounted on the movable vehicle part (vehicle seat). Both pot-type cores are designed as rails sliding along one another and having sections such that together they form a closed circuit for the magnetic flux between the primary winding and the secondary winding.