摘要:
The invention relates to a sensor (102) and a control unit (702) for cooperation with the sensor. The sensor (102) serves for measuring a velocity of a fluid (308) flowing through a channel (306). The sensor (102) employs a thermal measuring principle, which measuring principle is robust regarding disturbances on the amount of power dissipated by the heating element (106). A sensor receiver (110) is arranged for receiving an electromagnetic radiation generated by a control transmitter (722) comprised in a control (702) unit for cooperation with the sensor (102). The electromagnetic radiation is employed for powering the heating element (106) which is arranged for heating the fluid. On the basis of a measurement signal generated by a transducer arrangement comprised in the sensor (102), a control actuator (724) controls the velocity of the fluid. For this purpose a sensor transmitter (116) is arranged for transmitting the measurement signal to a control receiver (734).
摘要:
The invention relates to a sensor (102) and a control unit (702) for cooperation with the sensor. The sensor (102) serves for measuring a velocity of a fluid (308) flowing through a channel (306). The sensor (102) employs a thermal measuring principle, which measuring principle is robust regarding disturbances on the amount of power dissipated by the heating element (106). A sensor receiver (110) is arranged for receiving an electromagnetic radiation generated by a control transmitter (722) comprised in a control (702) unit for cooperation with the sensor (102). The electromagnetic radiation is employed for powering the heating element (106) which is arranged for heating the fluid. On the basis of a measurement signal generated by a transducer arrangement comprised in the sensor (102), a control actuator (724) controls the velocity of the fluid. For this purpose a sensor transmitter (116) is arranged for transmitting the measurement signal to a control receiver (734).
摘要:
An integrator circuit comprises an operational amplifier which has a transistor stage (1) with an input terminal (4) and an output terminal(3), a feedback capacitor (2) connected between the input terminal (4) and the output terminal (3), and a resistor (5) connected to the input terminal (4), and also has an additional circuit branch (20) comprising a second capacitor (22) and a second resistor (25) connected in series one with the other and connected between the output terminal (3) of the transistor stage (1) and voltage comprising the inverted input voltage to the integrator circuit. Preferably two additional circuit branches (320, 320′) are provided. One may be connected between the non-inverting or positive output terminal (33) of the transistor stage (1) and the inverting or negative input of the integrator. The other circuit may be connected between the negative output terminal (37) of the transistor stage (1) and the positive input of the integrator. This is particularly useful for balanced amplifier topology. The invention finds particular application in the first filter stage (integrator) in a sigma delta analog to digital conversion circuits and provide an improved operational amplifier integrator and particularly helps in compensating for a right halfplane zero.
摘要:
The invention relates to a magnetic sensor device comprising excitation wires (11, 13) for generating a magnetic excitation field and a magnetic sensor element, particularly a GMR sensor (12), for sensing magnetic fields generated by labeling particles in reaction to the excitation field. The magnetic excitation fields are generated with non-sinusoidal forms, particularly as square-waves, such that their spectral range comprises a plurality of frequency components. Magnetic particles with different magnetic response characteristics can then be differentiated according to their reactions to the different frequency components of the excitation fields. The magnetic excitation field and the sensing current driving the GMR sensor (12) are preferably generated with the help of ring modulators (22, 24). Moreover, ring modulators (27, 29) may be used for the demodulation of the sensor signal.
摘要:
Consistent with an example embodiment a, DA-converter system comprises the cascade of a multi-bit sigma-delta modulator and a DA-converter. The quantization noise of the sigma-delta modulator is isolated; the isolated quantization noise is word-length reduced in a second noise shaper with frequency independent signal transfer function and the isolated word-length reduced quantization noise is subtracted from the quantization noise of said cascade. In another embodiment, the isolated quantization noise is amplified before and attenuated after the second noise shaper.
摘要:
An analog-to-digital conversion arrangement for converting an analog input signal into a digital output signal with a most significant part and a least significant part comprises sample means for sampling the analog input signal, a plurality of coarse resolution analog-to-digital converters for converting the sampled analog input signal into a coarse digital signal representing the most significant part of the digital output signal, whereby the coarse resolution analog-to-digital converters are operated in an interleaved way. The analog-to-digital conversion arrangement further comprises a fine resolution analog-to-digital converter for converting the sampled analog input signal into a fine digital signal representing the least significant part of the digital output signal, based upon the coarse digital signal generated by any of said coarse resolution analog-to-digital converters.