Abstract: [Object] To significantly increased the convenience in suctioning dust on a mop with use of a negative pressure of an electric vacuum cleaner. [Solution] A hose coupling device 10 includes a connecting pipe 14, a branch pipe 15, a ball valve 40. The connecting pipe 14 has openings, one of the openings configured as a first inlet 31 and another one of the openings configured as an outlet 33 communicating with the one of the openings. The branch pipe 15 continues from a lateral surface of the connecting pipe 14 and has an opening configured as a second inlet 32. The ball valve 40 is arranged in a valve box 35 at which the connecting pipe 14 and the branch pipe 15 communicate such that the ball valve 40 is rotatable about a rotation axis corresponding to an axis of the branch pipe 15 while the ball valve 40 remains in contact with an inner wall of the valve box 35.

Abstract: [Object] An object is to easily suction dust/dirt on a cleaning portion of a mop as need arises without scattering the dust/dirt adhering to the mop when cleaning a floor with a vacuum cleaner while cleaning with the mop. [Solution] A mopstick (4) is inserted through an opening (13) on a cylindrical cleaning unit (6) of a mop dust suction device (3), which includes a hose coupling unit (7) detachably attached to a connection portion of a hose of a vacuum cleaner; a cleaning portion (5) of the mop is drawn into the cylindrical cleaning unit (6); the cleaning portion (5) of the mop is rotated in an arrow (B12) direction while the cleaning portion (5) of the mop is moved repeatedly in an arrow (A11) direction; and the dust/dirt adhering to the mop is easily suctioned and removed by suction force of a vacuum cleaner main body (1).

Abstract: [Object]An object is to easily suction dust/dirt on a cleaning portion of a mop as need arises without scattering the dust/dirt adhering to the mop when cleaning a floor with a vacuum cleaner while cleaning with the mop. [Solution]A mopstick (4) is inserted through an opening (13) on a cylindrical cleaning unit (6) of a mop dust suction device (3), which includes a hose coupling unit (7) detachably attached to a connection portion of a hose of a vacuum cleaner; a cleaning portion (5) of the mop is drawn into the cylindrical cleaning unit (6); the cleaning portion (5) of the mop is rotated in an arrow (B12) direction while the cleaning portion (5) of the mop is moved repeatedly in an arrow (A11) direction; and the dust/dirt adhering to the mop is easily suctioned and removed by suction force of a vacuum cleaner main body (1).

Abstract: A compensation circuit for pulse signals includes a noise pulse cutting circuit and a compensation pulse generating circuit. The noise pulse cutting circuit passes a reference pulse which is produced in each predetermined reference time period but blocks any other pulses until just before the next pulse is input after the reference pulse has passed. The compensation pulse generating circuit functions such that, when no pulse is input for a period of time slightly longer than the reference time period, a compensation pulse is generated and is input to the noise pulse cutting circuit. Even when there occurs noise in pulse signals, the circuit enables production of the same number of pulses as that of the reference pulses which are originally included in the pulse signals.

Abstract: In a field signal-frame signal conversion system including means for applying a delayed field signal delayed by 1/2 of one horizontal scanning period and a thru field signal, which is the same as the above field signal but not delayed, and switching means for alternately selecting the field signals at a time interval of one vertical scanning period to provide a frame signal, a circuit for preventing appearance of flicker attributable to the field signal-frame signal conversion, said circuit comprising a synchronizing signal separating circuit separating a synchronizing signal from the frame signal appearing at the output of said switching means, a sampling pulse generating circuit generating, in response to the application of the separated synchronizing signal, a sampling pulse signal synchronous with the change points from the sync tip level to the pedestal level and having a pulse width equal to or smaller than that of the serrating pulses, a sample and hold circuit operating in response to the sampling pul