摘要:
A vibration wave detector, having a receiver for receiving vibration waves such as sound waves and so on to be propagated in a medium, a resonant unit having a plurality of cantilever resonators each having such a length as to resonate at an individual predetermined frequency, a retaining rod for retaining the resonant unit, a vibration intensity detector for detecting the vibration intensity, for each predetermined frequency, of each of the resonators, by the vibration waves received by the receiver and propagated to the resonant unit by way of the retaining rod.
摘要:
A vibration wave detector, having a receiver for receiving vibration waves such as sound waves and so on to be propagated in a medium, a resonant unit having a plurality of cantilever resonators each having such a length as to resonate at an individual predetermined frequency, a retaining rod for retaining the resonant unit, a vibration intensity detector for detecting the vibration intensity, for each predetermined frequency, of each of the resonators, by the vibration waves received by the receiver and propagated to the resonant unit by way of the retaining rod.
摘要:
An apparatus for detecting an impedance variable in response to a sensed physical amount of a sensor is provided which comprises an impedance-frequency conversion unit and a counter. The impedance-frequency conversion unit converts the sensor impedance to an oscillation signal a frequency of which corresponds to the sensor impedance. The impedance-frequency conversion unit comprises an impedance-voltage converter for providing a voltage corresponding to the sensor impedance, and a Wien bridge oscillator including an element an impedance of which varies in response to the voltage from the impedance-voltage converter, for generating the oscillation signal. The Wien bridge oscillator is capable of generating a square wave signal as the oscillation signal. The counter counts the number of waves (or wave number) of the oscillation signal in a predetermined time period to output a count value which can be handled as a digital signal.
摘要:
A detection circuit which is capable of outputting a voltage proportional to a static capacitance of a sensor is provided, which comprises a voltage input terminal connected to receive an input voltage and an operational amplifier. The input voltage received at the voltage input terminal is changed between two different reference voltages. An inverting input terminal of the amplifier is connected to the voltage input terminal through a resistor, and a non-inverting input terminal of the amplifier is connected to the voltage input terminal through the sensor capacitance and to one of the reference voltages through a switch. An output voltage of the amplifier is connected to the inverting input terminal through a feedback circuit including a resistor and a switch. The switches are closed and the one of the reference voltages is supplied to the input terminal during an initialization cycle. The switches are opened and the other reference voltage is supplied to the input terminal during a measurement cycle. The operational amplifier outputs an output voltage which linearly varies in response to the sensor capacitance.
摘要:
Provided are a data obtaining section (21) that obtains a time-series data fluctuating in accordance with the plasma conditions, a translation error calculation section (24) that calculates a determinism providing an indicator of whether the time-series data in the plasma are deterministic or stochastic, from the time-series data that have been obtained in the data obtaining unit (21), and an abnormal discharge determination section (26) that determines that the plasma is under the abnormal discharge conditions, in the case that the value representing the determinism calculated in the determinism derivation unit is less than or equal to a given threshold value, during the plasma generation. Examples of the value representing the determinism include translation error or permutation entropy. In the case the permutation entropy is used as a value representing the determinism, a permutation entropy calculation section is provided.
摘要:
Provided are a data obtaining section (21) that obtains a time-series data fluctuating in accordance with the plasma conditions, a translation error calculation section (24) that calculates a determinism providing an indicator of whether the time-series data in the plasma are deterministic or stochastic, from the time-series data that have been obtained in the data obtaining unit (21), and an abnormal discharge determination section (26) that determines that the plasma is under the abnormal discharge conditions, in the case that the value representing the determinism calculated in the determinism derivation unit is less than or equal to a given threshold value, during the plasma generation. Examples of the value representing the determinism include translation error or permutation entropy. In the case the permutation entropy is used as a value representing the determinism, a permutation entropy calculation section is provided.
摘要:
A static capacitance-to-voltage converter is capable of converting a static capacitance into a voltage without suffering from a stray capacitance formed between a signal and a shielding line or a stray capacitance formed between an exposed portion of the signal line and its surroundings. The static capacitance-to-voltage converter is formed of an operational amplifier placed in an imaginary short-circuit state between an inverting input and a non-inverting input thereof; a signal line having one end connected to the inverting input and the other end capable of being connected to a static capacitance; a shielding line surrounding the signal line and connected to the non-inverting input; an alternating current signal generator for applying the non-inverting input with an alternating current signal; and zero adjusters for adjusting the output of the static capacitance-to-voltage converter to minimum when no static capacitance is connected to the signal line.
摘要:
A impedance-to-voltage converter for converting an impedance of a target to a voltage is described which comprises an operational amplifier (OP), a coaxial cable consisting a signal line and shielding element(s), and an AC signal generator. A feedback impedance circuit is connected between output and inverting terminals of the OP, and whereby a non-inverting terminal and the inverting terminal are an imaginal-short condition. One end of the signal line is connected to the inverting input terminal of the OP and the other end is connected to one electrode of the target and the AC signal generator is connected to the non-inverting input terminal of the OP. The shielding element comprises at least one shielding layer surrounding the signal line and is connected to the non-inverting input terminal of the OP, and thus the signal line and the shielding layer are the same voltage due to the imaginal-short of the input terminals of the OP, resulting in reduction of noise on the signal line.
摘要:
An impedance-to-voltage converter utilizes an operational amplifier to convert an impedance into a voltage without suffering from the influence of stray capacitances. The impedance-to-voltage converter is formed of an operational amplifier which has an imaginary short-circuit state between an inverting input and a non-inverting input thereof when an impedance element is connected between an output and the inverting input, a shielding line for shielding a line for connecting the impedance element to the inverting input, an AC signal generator connected to the non-inverting input, and a shielding line for shielding the signal line. The shielding lines are connected to the non-inverting input.
摘要:
A small sensor circuit with reducible electric power consumption is formed by connecting inverting amplifiers comprised of CMOS inverters connected in an odd number of stages, in series to guarantee the linearity of the relationship between inputs and outputs, and connecting an impedance as a sensor between the inputs and outputs, or to an input.