摘要:
A howling prevention apparatus prevents a howling noise which is generated in a sound amplification system using a microphone and a loudspeaker. The howling prevention apparatus utilizes a plural number of first to n-th equalizers, which have a variable frequency response and which modulate an output of the microphone. A detector detects a frequency point at which a loop gain of the system reaches a peak while supplying a standard noise signal to the loudspeaker to produce a test sound and measuring the sound collected by the microphone through the series of the equalizers. A frequency response of the first equalizer is adjusted to suppress a noise peak at and around a frequency point detected by the detector. Then, a frequency response of the second equalizer is also adjusted to suppress a noise peak at and around another frequency point detected by the detector. Lastly, a frequency response of the n-th equalizer is adjusted by subsequently repeating the above setting procedure.
摘要:
A wood board comprising a core layer comprising one or more strand boards formed by using a foaming binder, and at least one surface layer comprising oriented strand board, which is laminated to at least one surface of the core layer, the foaming binder being a mixture of a foaming resin and a non-foaming resin at a ratio within a range of 4:1-1:4. It is preferable that the thin wooden strips comprising the surface layer has at least one of an average length value and an average width value thereof which is larger than that of the thin wooden strips comprising the core layer. The wood board of the present invention has particularly superior resistance to moisture, and has low density and high strength. In the wood board of the present invention, it is possible to adjust the anisotropy of the strength thereof by adjusting the number of layers or the thickness thereof. The present invention furthermore provides a flooring material having high strength in which a decorative single sheet is applied to at least one surface of the wood board described above.
摘要:
A stator for miniature motors having a permanent magnet fixedly fitted to the inner circumferential surface of a housing formed into a bottomed hollow cylindrical shape, in which the circumferential surface of the housing consists of two opposing flat parts and two concave cylindrical surfaces; engaging projections are provided on the flat parts, and flat surfaces coming in contact with said flat parts, and engaging surfaces facing coming in contact with the engaging projections are provided on the axial edge of the permanent magnet made of a flexible ferromagnetic material, and formed into an arc-segment shape in cross section; and the permanent magnet is fixedly fitted in the housing by bringing the arc-segment-shaped outer circumferential surfaces of the permanent magnet in contact with the cylindrical surfaces of the housing, and bringing the flat surfaces on the axial edges of the permanent magnet in contact with the flat parts by causing the engaging projections to cut into the engaging surfaces by the plastic deformation of the engaging projections in a state where the permanent magnet is inserted into the housing.
摘要:
An electronic musical instrument includes a key support portion, a plurality of keys pivotally supported on the key support portion, a musical tone signal generator, after sensors, and a musical tone signal control unit. The musical tone signal generator generates a musical tone signal corresponding to each of the plurality of keys. Each after sensor has a plurality of sensors and is arranged in correspondence with the plurality of keys and operated near key depression end positions to for independently generate pieces of key information. The musical signal control unit controls the musical tone signal generator on the basis of the key information.
摘要:
An elevator control apparatus has a converter for converting AC power to DC power, an inverter for converting the DC power resulting from the conversion by the converter into AC voltage of a variable voltage and a variable frequency so as to drive with the AC voltage an induction motor for vertically moving an elevator car, a current detector for detecting the current output by the inverter and for producing an output signal indicative of the detected current, a current command generating circuit for generating a current command value for the induction motor, and a control circuit for controlling the inverter on the basis of both the current command value from the current command generating circuit and the output signal from the current detector. The control apparatus includes a cancellation circuit for cancelling offset voltage by storing, when the inverter is stopped while the current command generating circuit keeps generating the current command value, the output signal of the current detector, and by adding, when the inverter is in operation, the stored output signal to the present output signal of the current detector.
摘要:
A memory has plural storage areas for storing performance data of plural music pieces. When the player has input desired performance data via an input device like a keyboard, the thus-input performance data are automatically stored into a first storage area of the memory. At the same time, a specific search is executed by the search section to examine whether or not performance data of a music piece corresponding to the input performance data are already stored in the memory. If a second storage area storing the performance data corresponding to the input performance data has been detected or searched out, a series of the performance data stored in the second storage area are sequentially read out for an automatic reproductive performance. If, on the other hand, such a second storage area has not been detected, writing of the input performance data into the first storage area is continued without such an automatic reproductive performance being executed. Therefore, it is sufficient for the player to perform an operation to input a part or whole part of the desired music piece. Then, in response to the player's input operation, music piece number selection and readout or write processes are automatically carried out in accordance with the result of the search by the search section.
摘要:
An electromagnetic fuel injection valve comprises a valve body, a valve seat which cooperates with the valve body, a fuel injection port disposed downstream of the valve seat, and a dividing device which serves to divide injection fuel injected from the fuel injection port. The dividing device is formed integrally with a member in which the fuel injection port is formed and includes parallel walls substantially parallel to each other with the fuel injection port interposed therebetween and arcuate walls connected to the parallel walls having a diameter larger than that of the fuel injection port. The walls extend from said member in a direction of an axis of the valve. The dividing device has an outer diameter substantially equal to the largest diameter of the valve seat.
摘要:
An electric contact material containing Li oxide of 0.01 to 2.0% by weight when represented in terms of the amount of Li, oxide of at least one rare earth element of 0.05 to 0.18% by weight when represented in terms of the amount of the rare earth element, and Ag or Ag alloy as the remaining portion; an electric contact material containing Li oxide of 0.01 to 2.0% by weight when represented in terms of the amount of Li, at least one rare earth element of 0.05 to 0.18% by weight when represented in terms of the amount of the rare earth element, at least one element selected from a group consisting of In, Sn, Zn, Mn, Pd, Sb, Cu, Mg, Pb, Cd, Cr and Bi by an amount of 0.1 to 1.0% by weight (however, in the case of Zn and Mn, the amount is set less than 0.5% by weight), and/or at least one element selected from a group consisting of Fe, Ni and Co by an amount of 0.03 to 0.6% by weight, and Ag as the remaining portion; and an electric contact formed by using the above material. It is excellent in the arc resistance, wear resistance an lubricity in a small current region and is suitable as the material for a slide contact and rotary slide contact.
摘要:
A miniature motor having a housing formed into a bottomed hollow cylindrical shape. The inner circumferential surface to which a pair of permanent magnets, which are rare-earth plastic magnets of an essentially C shape in cross section, are fixedly fitted. An end cap is fitted to an open end of the housing, and a rotor is rotatably supported in the housing by bearings provided on the housing and the end cap. A pair of the permanent magnets are formed in such a manner that the magnetic force of each magnet is made different from each other so that the rotor can be attracted to the permanent magnet having a larger magnetic force. One of the permanent magnets is made of a rare-earth plastic magnet containing a coloring material.