摘要:
An anti-theft system for a motor vehicle includes a portable transponder carrying code information. A stationary transceiver has an oscillator and an oscillating circuit being excited to oscillate by the oscillator at an oscillation being modulated by the transponder in synchronism with the code information. A demodulator demodulates the modulated oscillation of the oscillating circuit. According to one embodiment, the code information is obtained from the demodulated oscillation by sampling the oscillation at least at one predetermined sampling time. An arithmetic unit compares the code information with command code information and transmits an enable signal to a security unit if a match occurs. The modulated oscillation being shifted by a predetermined phase angle is sampled once again if initially no code information is recognized from the demodulator. According to another embodiment, the modulated oscillation containing the code information is sampled at least at two predetermined times being phase-shifted from one another by a predetermined phase angle and the code information is obtained from voltage values detected at the sampling times. The arithmetic unit compares the code information with the command code information and transmits an enable signal to a security unit if a match occurs.
摘要:
In an anti-theft system for a motor vehicle, an oscillating circuit of a transceiver in the motor vehicle is modulated with code information of a portable transponder. A demodulator detects the code information and carries it onward to a computer unit, where it is checked for authorization. Component tolerance or temperature changes can mean that initially no code information will be demodulated, despite a properly functioning transponder. According to the invention, the frequency of the modulated oscillation is then measured and reregulated to a command frequency.
摘要:
In order to identify the position of a movable element, such as a lock bolt, a resonant circuit is subjected to the element or a part that moves with the element. The resonant circuit is thereby damped by the element in a position-dependent manner and oscillates in one end position of the element but is damped too greatly in the other end position. A microprocessor controls the switching on and the respective operating point of a transistor in such a way that switching hysteresis is obtained. The operating point can be automatically readjusted in an adaptation phase.
摘要:
The invention relates to a temperature sensor comprising a sense element and being in contact with a housing configured as a contact wire of the temperature sensor. A contact wire arranged inside the housing, is configured concentrically and is held under spring tension with an angular spring. For testing purposes, a testing resistor, being connected parallel to the sensor element is proposed.
摘要:
The invention relates to a pressure sensor device comprising a membrane body in the form of a membrane whose first side is exposed to a working medium whereas the second side thereof is arranged oppositely to the first side. The inventive device also comprises at least one pressure sensor element (16, 18) for detecting the extension or compressive strain of the membrane body produced by the working medium pressure. A temperature sensor element (22) for detecting the membrane body temperature is mounted thereon.
摘要:
A device for measuring a temperature of an exhaust gas flow in an exhaust branch of an exhaust gas section of an internal combustion engine is disclosed. A sub-region of the exhaust branch is configured as a parabolic mirror having a focal point positioned outside of the exhaust branch. The device includes a side channel member attached to the exhaust branch and having an open end adjacent to the exhaust branch and a closed end; and a radiation sensitive sensor disposed in the side channel member and at the focal point. The open end is in fluid communication with an interior of the exhaust branch through a cutout of the exhaust branch so that the sensor is coupled to radiation of the exhaust gas flow for measuring a temperature of the exhaust gas flow. A related method is also disclosed.
摘要:
A radiation-measurement circuit for a photodiode has a microprocessor providing a pulse-width-modulated voltage signal via a low-pass filter to the cathode of the photodiode. The voltage which is applied to the cathode of the photodiode is detected via an input of the microprocessor and is regulated at a nominal value by adjusting the modulated voltage signal of the microprocessor. The circuit has a particularly wide dynamic measurement range.
摘要:
In a method for operating an anti-theft system and an anti-theft system operating according to the method, a stationary transceiver sends a question code signal to a portable transponder, which in turn responds with an answer code signal. The answer code signal is scanned at predetermined scanning times and a piece of code information is demodulated therefrom. If the first bits of the answer code signal are already unreadable, then the scanning time is displaced by a phase angle, and the remainder of the answer code signal is read.
摘要:
A device for transmitting data or energy supply from or to a transponder, especially for an anti-theft system in a motor vehicle, includes an antenna oscillating circuit which is induced to oscillate by an exciter variable. The oscillation is transmitted by transformer coupling to a transponder oscillating circuit. In order to make the transmission of energy or data as effective as possible, the current or the voltage in the antenna oscillating circuit is measured and compared with a desired variable. Upon a deviation, a correction value is generated by which the exciter current is increased or the resonant frequency is adapted to the exciter frequency as a consequence of the addition of an impedance to the antenna oscillating circuit.
摘要:
Control device for controlling functions of a motor vehicle for a load dump having a computer for generating at least one control signal that is dependent on the level of the operating voltage feeding the control device. A power supply system generates an operating voltage that is supplied to a threshold switch. As long as the operating voltage is above a limit value in the load dump case, the threshold switch outputs a response signal to an evaluator. The latter then only supplies an output signal and thus reports the load dump case to a computer unit when the response signal lasts longer than a set time span.