Electric floor cleaner with a soft start function
First Claim
1. An electrical floor cleaner comprising:
- voltage doubling and rectifying means for voltage doubling and rectifying a single-phase commercial power source voltage input through a power switch;
an inverter for converting a doubled d.c. voltage from said voltage doubling and rectifying means into three-phase a.c.;
control means for controlling voltage and frequency of said three-phase a.c. for switching elements of said inverter for a predetermined period of time after said power switch is put into an on state from an off state, said control means controlling said voltage and frequency according to a predetermined combination thereof, said voltage and frequency are different from rated values thereof, therein providing a soft start;
a three-phase motor arranged to be driven by said three-phase a.c. applied from said inverter, said three-phase motor having a rated voltage which is substantially equal to the doubled voltage; and
a floor cleaning member arranged to be driven by said three-phase motor.
1 Assignment
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Accused Products
Abstract
An electric floor cleaner is of the type arranged to drive a three-phase motor, whose rated voltage is substantially equal to a voltage obtained by voltage doubling and rectifying a single-phase commercial power line and then by converting a voltage doubled d.c. voltage into three-phase a.c. by an inverter. The voltage and frequency of the three-phase a.c. output from the inverter are controlled for a predetermined period of time after a power switch is put into a turned on state from a turned off state. It is therefore possible to reduce the starting current to a small value enabling the use of a larger rated output motor than a motor in a conventional system within an allowable current limit of a commercial power line.
36 Citations
6 Claims
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1. An electrical floor cleaner comprising:
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voltage doubling and rectifying means for voltage doubling and rectifying a single-phase commercial power source voltage input through a power switch; an inverter for converting a doubled d.c. voltage from said voltage doubling and rectifying means into three-phase a.c.; control means for controlling voltage and frequency of said three-phase a.c. for switching elements of said inverter for a predetermined period of time after said power switch is put into an on state from an off state, said control means controlling said voltage and frequency according to a predetermined combination thereof, said voltage and frequency are different from rated values thereof, therein providing a soft start; a three-phase motor arranged to be driven by said three-phase a.c. applied from said inverter, said three-phase motor having a rated voltage which is substantially equal to the doubled voltage; and a floor cleaning member arranged to be driven by said three-phase motor. - View Dependent Claims (2, 3, 4, 5)
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6. An electrical floor cleaner comprising:
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voltage doubling and rectifying means for voltage doubling and rectifying a single-phase commercial power source voltage input through a power switch; an inverter for converting a doubled d.c. voltage from said voltage doubling and rectifying means into three-phase a.c.; control means for controlling timing of conduction of switching elements of said inverter so as to control voltage and frequency of said three-phase a.c. for a predetermined period of time after said power switch is put into an on state from an off state, said control means including a manually operable dip switch having a plurality of circuits, and a memory means for storing a plurality of patterns of relationship between voltages and frequencies which are designated by said manually operable dip switch; a three-phase motor arranged to be driven by said three-phase a.c. applied from said inverter, said three-phase motor having a rated voltage which is substantially equal to the doubled voltage; and a floor cleaning member arranged to be driven by said three-phase motor.
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Specification