PURPOSE: To reduce the number of wirings from a vacuum body to receptacles so as to eliminate the polarity in order to enhance the workability by determining the front half and rear half of a half wave having an a.c. power source phase and superposed in a pair of electric wires.
CONSTITUTION: As the input voltage of a portable hose communication control part is increased by manipulating a slide volume, the signal transmission frequency of an a.c. half wave in the front half period becomes heigh. The higher the frequency of a received signal is, the more is the power to a body side communication control part 11 fed to a fan motor 10 so as to increase the suction force. Meanwhile, the body side communication control part 11 transmits a high-frequency signal in association with a signal from a dustfull detecting part 15 so as to superpose the signal in a pair of electric wires 9 during a period when a body side a.c. phase determining part 16 indicates the rear haif of the a.c. half wave. When a portable hose a.c. phase determining part delivers a signal indicating the later half of the a.c. half wave, the signal is received so as to turn on a lamp in a display part so as to inform a dust-full condition. Further, a switch in a control part 5 is closed, an a.c. power source feed part 13 in the body 1 delivers a power to a power nozzle motor through the pair of electrical wires 9 and connection terminals in receptacles 2a, 2b, which is therefore rotated.
TAKAHASHI MASAKI
TAKASHIMA YOSHINORI
