Hitachi Koki Co., Ltd.

Kumio Takahashi

Masahiro Inaniwa

Yoshimasa Hayama

Daisuke Kakegawa

Toshiaki Koizumi

Shun Suzuki

To provide a dust collector which, even when it is used in a poor power supply situation, can detect the dust loading of a filter accurately, can remove dust automatically and can reduce power consumption. In the dust collector, there is provided a control circuit which can detect the dust loading of a filter by comparing the threshold value of the dust loading pressure to be determined by the internal pressure of the filter, the operation of a suction device, the power supply frequency of the suction device and the supply voltage of the suction device with the filter internal pressure just before the suction device stops, and, when the filter is dust loaded, can operate a dust removing device.

Dust collector

A dust collection device has a tank, a suction unit, a filtering unit, a dust removal unit, a first detection unit, and a control unit. The tank has an air inlet for accommodating dust. The suction unit aspirates the dust through the air inlet. The filtering unit captures the dust through the air inlet. The dust removal unit removes the dust from the filtering unit. The first detection unit detects an operational state of the suction unit. The control unit controls the suction unit and the dust removal unit. The control unit activates the dust removal unit, when the first detection unit detects that the suction unit operates for a first predetermined time period and then stops operating.

Dust collection device

An electromagnetic disturbance power (EDP) checker measures disturbance waves of an equipment under test (EUT), that is, a small electric appliance having a power cord. The EDP checker is capable of detecting and measuring disturbance waves even in sites more confined and having more external disturbance waves than in absorbing clamp method. The EDP checker includes a VHF current probe 2, a matching circuit 3 having input impedance matched at a reception frequency of a measuring equipment (receiver) 6 connected to the VHF current probe 2, and a circuit separating mains 4 for designating terminal impedance of the matching circuit 3 and eliminating influence of power source impedance. Power is supplied from the circuit separating mains 4 to drive the EUT 5 connected to the VHF current probe 2. The maximum value of disturbance power generated by the EUT 5 and supplied through the power cord 12 is measured by the measuring equipment 6 connected to the VHF current probe 2.

Growing community of inventors

Ibaraki, Japan

Kumio Takahashi