摘要:
The present invention relates to a method of and an apparatus for measuring flow velocity by using ultrasonic waves. Sound velocities of wedge portions constituting ultrasonic transducers provided at the upstream and the downstream sides of a piping, respectively, are measured, and the ultrasonic wave is oscillated from the upstream side to the downstream side and from the downstream side to the upstream side, respectively, and propagated in a fluid in the piping and respective times from the oscillating to receiving are measured. These measured values are substituted into a predetermined function and calculated, to thereby search the flow velocity of the fluid in the piping. Each of the ultrasonic transducers is connected thereto with a transmission-reception changeover section, a timer device for measuring a propagation time, during which the ultrasonic wave is propagated in the fluid in the piping and received, and an operational device for processing output data, which is delivered from the timer device in a predetermined manner. An opening length of the ultrasonic transducer in contact with the piping is about 15 wave lengths or more of a center frequency used, whereby the ultrasonic waves become parallel beams, so that an angle of directivity becomes small.
摘要:
A dispenser includes a cartridge moving mechanism and a hopper. The cartridge moving mechanism moves between a cartridge receiving position and an extracting position and between the extracting position and a cartridge exhaust position. The hopper has a dropping unit and is disposed immediately above the cartridge receiving position. The dropping unit serves to drop a cartridge consisting of a fluid-impermeable outer frame and a filters. A space defined between the filters and the outer frame and contains a powdery or granular material to be extracted. An extracting mechanism of the dispenser has an upper extracting head, and a lower extracting head including an extracting tank. The upper extracting head is provided above the extracting position and has an extracting chamber. The extracting tank is provided below the extracting position to face the upper extracting head, and another extracting chamber is formed in the extracting tank. The lower extracting head has a heater for heating the extracting tank and a liquid heating passage communicating with the extracting chamber. The dispenser effectively obtains an extract from the material of the cartridge by dripping.
摘要:
An improved apparatus for forming an elongated synthetic resin plate or sheet, is provided. The lower steel belt of the apparatus is placed on a lower board and is intermittently fed by a predetermined distance. Side frames are installed on the lower steel belt, the side frames stretching on both the right and left edges of the lower steel belt in the lengthwise direction thereof. The upper steel belt is disposed between the two side frames, and an upper board is installed on the upper steel belt. Either one of the upper board or the lower board is so constructed as to be movable up and down. The resinous starting material is pressed by the pressing operation of the board which moves up and down via the upper and lower steel belts. The upper and lower boards are divided into a plurality of blocks so as to correspond to the opposing ones, thereby to constitute heating zones having heating means and cooling zones having cooling means.
摘要:
A single pickup head generates an alternating signal proportional to the rotational speed of a DC motor which can be rotated in either of two directions, and such alternating signal is employed by speed and/or phase control circuits to control the motor speed relative to a reference speed in a selected one of the two directions. An overspeed sensing circuit detects speed runaway, which can occur when the motor is rapidly rotated in the direction opposite to the selected direction, and the overspeed sensing circuit then interrupts the motor drive voltage until the motor speed decreases to below its normal speed. At and below normal speed in the undesired direction, the normal torque acts in the selected direction to rapidly reverse the direction and to accelerate the motor to normal speed in the selected direction.
摘要:
A drive circuit for a brushless motor of the type having a rotor magnet and energizable stator windings. The drive circuit includes position sensors for sensing the rotary position of the rotor magnet and for generating varying position signals corresponding to the sensed rotary position. A plurality of amplifier stages is coupled to the position sensors, the amplifier stages being responsive to the position signals to produce drive currents which are supplied to the stator windings. In one embodiment, each amplifier stage includes a voltage amplifier having a linear gain characteristic for amplifying the position signal applied thereto, a current amplifier connected in cascade with the voltage amplifier and responsive to the amplified position signal to produce a drive current, and a feedback circuit interconnected between the output of the current amplifier and the input to the voltage amplifier, the feedback circuit including a resistor and a capacitor connected in parallel and operative as a low pass filter circuit to prevent harmonics of the drive current frequency from being transmitted to the stator winding, thereby preventing notching in the drive current.In another embodiment, the drive circuit also includes a speed sensor for sensing the speed of the motor and for generating a signal whose frequency varies in accordance with the motor speed, a converter coupled to the speed sensor for converting the frequency of the generated signal to a voltage, a circuit for applying the converted voltage to the position sensors so as to modify the position signals in accordance with the sensed motor speed, and a circuit for supplying an offset voltage to the last-mentioned circuit such that if the speed of the motor exceeds a predetermined amount, the offset voltage exceeds the converted voltage whereby the resultant voltage which is applied to the position sensors causes a modification in the drive currents supplied to the stator windings, to produce an opposite torque in the motor. In this embodiment, excess motor speeds are rapidly corrected.
摘要:
According to one embodiment, a postal indicium detection method includes detecting whether or not one of a first face and a second face of a sheet corresponds to a picture card specific face, detecting a postal indicium candidate from the second face based on a first detection result indicating that the first face corresponds to the picture card specific face, and detecting the postal indicium candidate from the first face based on a second detection result indicating that the second face corresponds to the picture card specific face.
摘要:
A linear actuator displaces a relative position between a guide rail and a slide table, which is arranged in confronting relation to the guide rail. Projections are formed on opposite end sides of the guide rail, the projections extending along a direction of displacement and projecting toward the slide table. The slide table is disposed between the projections on the opposite end sides of the guide rail, with rigid balls being interposed therebetween. Guide grooves and guide grooves, which rollably support the balls, are provided on the projections on the opposite end sides of the guide rail and on the slide table. The guide grooves and the guide grooves apply, on the balls, a pressure caused by a magnetic attractive force of permanent magnets.
摘要:
An ionizer includes positive and negative wire electrodes each formed of a conductive wire with a circular cross section. The wire electrodes are arranged in parallel with each other, each having circumferential surfaces serving as a discharge surface on which a corona discharge occurs upon application of positive and negative high voltages for discharging positive and negative ions.