Abstract: A rotation speed detection device includes a blade detection sensor located in a housing of a turbocharger and that outputs an output voltage that fluctuates according to an approaching of a blade of a compressor wheel to the blade detection sensor and a separation of the blade from the blade detection sensor, and a sensor circuit to binarize an output signal of the blade detection sensor into a high signal and a low signal and to output the signals. The sensor circuit includes a low pass filter to cut off a high frequency component of the output signal by an analog filter or a digital filter, a high pass filter to cut off a low frequency component of the output signal by a digital filter, and a control unit to increase a cut-off frequency of the high pass filter in accordance with an increase in rotation speed of the turbocharger.

Abstract: A dielectric member includes a first bobbin, which is located on a radially outer side of a first core, a holder, which receives a magnet, and a second bobbin, which is located on a radially outer side of a second core. A first terminal and a second terminal are fixed to a terminal fixing portion. A wire continuously forms a first connecting portion, which is connected to the first terminal, a first coil portion, which is wound around the first bobbin, a first crossover portion, which traverses from the first coil to the second bobbin over the holder, a second coil portion, which is wound around the second bobbin, a second crossover portion, which traverses from the second coil portion to the first coil portion over the holder, and a second connecting portion, which is connected to the second terminal.

Abstract: A rotation number detector outputs a signal based on a detection signal from a sensor, the detection signal reflecting a movement of a detected portion of a detection object. The output signal from the sensor is rectified by a comparator. A cycle measurement circuit measures a cycle of a rectangular wave signal from the comparator. A variable divider variably divides the cycle in reverse proportion to the measured cycle of the cycle measurement circuit, dividing the cycle by a smaller dividing ratio when the measured cycle becomes longer and dividing the cycle by a greater dividing ratio when the measured cycle becomes shorter. A one shot circuit converts the rectangular wave signal of the variable divider to a signal having a dividing ratio discernible wave form, which represents the dividing ratio of the variable divider, and outputs such a signal.

Abstract: A dielectric member includes a first bobbin, which is located on a radially outer side of a first core, a holder, which receives a magnet, and a second bobbin, which is located on a radially outer side of a second core. A first terminal and a second terminal are fixed to a terminal fixing portion. A wire continuously forms a first connecting portion, which is connected to the first terminal, a first coil portion, which is wound around the first bobbin, a first crossover portion, which traverses from the first coil to the second bobbin over the holder, a second coil portion, which is wound around the second bobbin, a second crossover portion, which traverses from the second coil portion to the first coil portion over the holder, and a second connecting portion, which is connected to the second terminal.

Abstract: A rotation number detector outputs a signal based on a detection signal from a sensor, the detection signal reflecting a movement of a detected portion of a detection object. The output signal from the sensor is rectified by a comparator. A cycle measurement circuit measures a cycle of a rectangular wave signal from the comparator. A variable divider variably divides the cycle in reverse proportion to the measured cycle of the cycle measurement circuit, dividing the cycle by a smaller dividing ratio when the measured cycle becomes longer and dividing the cycle by a greater dividing ratio when the measured cycle becomes shorter. A one shot circuit converts the rectangular wave signal of the variable divider to a signal having a dividing ratio discernible wave form, which represents the dividing ratio of the variable divider, and outputs such a signal.

Abstract: A magnet generates a magnetic field around a position where a detected object passes. The detected object is formed of a nonmagnetic and conductive material. A first core is a magnetic object equipped to the magnet on a detected object side. A coil is wound around a radially outside of the first core. A second core is a magnetic object connected to the first core on the detected object side. An outer diameter of the second core is greater than an outer diameter of the first core.

Abstract: A fuel pipe is mounted to a vehicle body. A detection electrode is immersed in fuel, which flows through the fuel pipe. A grounding electrode is in a tubular member and is located outside the detection electrode. An affixing member affixes the fuel pipe and the grounding electrode in a state where the fuel pipe and the grounding electrode are electrically isolated from each other. A detection circuit detects a capacitance between the detection electrode and the grounding electrode according to a specific inductive capacity of fuel, which flows between the detection electrode and the grounding electrode. A conductive shield portion extends from an end of the grounding electrode and extends between the detection electrode and the fuel pipe. The end of the grounding electrode is immersed in fuel, which flows through the fuel pipe.

Abstract: In a range detection device, a movable member has a magnetized portion and can move with a manual valve of a control device. A supporting member includes a plate portion having a surface opposed to the magnetized portion and a recess formed in an opposite surface of the plate portion, and supports the movable member such that the movable member is capable of moving parallel with the plate portion. A substrate is placed in the recess and has a first hole that penetrates the substrate. A magnetic detection element is installed to a surface of the substrate at a side of the plate portion to correspond to a position of the first hole, and detects magnetism of the magnetized portion. A sealing member is filled in the recess and covers the substrate and the magnetic detection element.

Abstract: A liquid concentration measuring device has first and second switches, which are turned on and off at two frequencies. When the first switch is turned on and the second switch is turned off, a detection electrode pair is charged. When the first switch is turned off and the second switch is turned on, the positive side of the detection electrode pair is grounded so that the charged detection electrode pair discharges. The difference between the output voltages of an amplifier produced by charging and discharging the detection electrode pair at the two frequencies is used to determine an alcohol concentration in gasoline.

Abstract: In a range detection device, a movable member has a magnetized portion and can move with a manual valve of a control device. A supporting member includes a plate portion having a surface opposed to the magnetized portion and a recess formed in an opposite surface of the plate portion, and supports the movable member such that the movable member is capable of moving parallel with the plate portion. A substrate is placed in the recess and has a first hole that penetrates the substrate. A magnetic detection element is installed to a surface of the substrate at a side of the plate portion to correspond to a position of the first hole, and detects magnetism of the magnetized portion. A sealing member is filled in the recess and covers the substrate and the magnetic detection element.

Abstract: A liquid concentration sensor includes an electrode capacitance conversion circuit, a stray capacitance conversion circuit and a difference calculation circuit. The electrode capacitance conversion circuit includes a detection electrode and a switching device. The detection electrode has a pair of opposing terminals and is partially located in a liquid fuel. The switching device is turned ON and OFF to switch between charging and discharging of the detection electrode. The electrode capacitance conversion circuit outputs a first measurement value determined by the charging and discharging of the detection electrode. The stray capacitance conversion circuit has the almost same configuration as the electrode capacitance conversion circuit so as to output a second measurement value corresponding to a stray capacitance of the electrode capacitance conversion circuit. The difference calculation circuit outputs a difference between the first and second measurement values.

Abstract: A liquid concentration measuring device has first and second switches, which are turned on and off at two frequencies. When the first switch is turned on and the second switch is turned off, a detection electrode pair is charged. When the first switch is turned off and the second switch is turned on, the positive side of the detection electrode pair is grounded so that the charged detection electrode pair discharges. The difference between the output voltages of an amplifier produced by charging and discharging the detection electrode pair at the two frequencies is used to determine an alcohol concentration in gasoline.

Abstract: A precipitation sensor has a prism bonded to a front windshield, a beam transmitter, and a beam receiver. The prism has an entry-side prism wall, a connection wall, and an exit-side prism wall. The entry-side prism wall of the prism parallelizes light transmitted from the beam transmitter by refracting them on a convex lens face. The parallelized light is reflected from a parabolic outer face of the prism wall toward the inner face of the windshield. The parallel beams reflected from the inner face of the front windshield are reflected from a parabolic outer face of the exit-side prism wall and then focused on the beam receiver through a convex lens face of the prism wall. The convex shapes of the lens faces form arcs, the centers of which are aligned with the beam transmitter and the beam receiver, respectively.

Abstract: In an apparatus S, a peripheral light beam detecting light-receiving element 5 is disposed on a substrate 3 carrying a light-emitting element 4 and a light-receiving element 5 for detecting a raindrop. The peripheral light beam detecting light-receiving element 5 and the light receiving element 5 for detecting a raindrop are the same element. A plano-convex lens 10 is disposed so that a convex wall 10a thereof is opposed to the light-receiving element 5; the plano-concave lens 11 is disposed so that a concave wall 11a thereof is opposed to a plane wall 10b of the plano-convex lens 10, and a plane wall 11b of the plano-convex lens 10 is in tight or substantially tight contact with the inside wall 9b of the front windshield 9, whereby the peripheral light beams are collected to the light-receiving element 5 via the plano-concave lens 11 and the plano-convex lens 10.

Abstract: A precipitation sensor has a prism bonded to a front windshield, a beam transmitter, and a beam receiver. The prism has an entry-side prism wall, a connection wall, and an exit-side prism wall. The entry-side prism wall of the prism parallelizes light transmitted from the beam transmitter by refracting them on a convex lens face. The parallelized light is reflected from a parabolic outer face of the prism wall toward the inner face of the windshield. The parallel beams reflected from the inner face of the front windshield are reflected from a parabolic outer face of the exit-side prism wall and then focused on the beam receiver through a convex lens face of the prism wall. The convex shapes of the lens faces form arcs, the centers of which are aligned with the beam transmitter and the beam receiver, respectively.