Patent Publication Number: US-7898209-B2

Title: Cleaner and method for driving the same

Description:
FIELD OF THE INVENTION 
     The present disclosure relates to a power control system for controlling a voltage supplied to a motor. More particularly, the present disclosure relates to a power control system for controlling a voltage supplied to a motor for use in a vacuum cleaner. 
     BACKGROUND 
     The present disclosure relates to a cleaner for collecting pollutant particles such as dust and dirt and a method for driving the cleaner. 
     A cleaner makes it possible to clean a desired region without scattering pollutant particles such as dust and dirt. The reason for this is that the cleaner collects (or traps) pollutant particles by inhalation (suction). In order to collect pollutant particles, the cleaner has a collecting fan that is rotated by an electric motor. 
     The cleaner uses an AC voltage of about 110 V or 220 V or a DC voltage of a battery to drive the collecting fan. That is, cleaners are classified into an AC voltage cleaner and a DC voltage cleaner. 
     The AC voltage cleaner is equipped with a power cord for receiving the AC voltage. This power cord, however, restricts a possible cleaning region that can be cleaned using the cleaner. Thus, when a wide region needs to be cleaned, a user of the cleaner must repeat reconnection of the power cord. 
     The DC voltage cleaner restricts the possible time during which the cleaner may be used. In actuality, the DC voltage cleaner can be used only when a battery is charged with a voltage. Upon completion of discharge of the battery, the DC voltage cleaner cannot be used until the battery is charged with a voltage. 
     SUMMARY 
     Embodiments provide a cleaner that can be operated by a battery voltage as well as by an AC voltage, and a method for driving the cleaner. 
     Embodiments also provide a cleaner whose AC and DC voltage modes can be automatically switched, and a method for driving the cleaner. 
     Embodiments also provide a cleaner whose battery can be actively charged. 
     In one embodiment, a cleaner includes: a motor for rotating a collecting fan; a battery; a voltage converter for converting an AC voltage received from a power source into a DC voltage; an active voltage selector for selecting a voltage of the battery and the DC voltage; and a motor driver for driving the motor using the voltage selected by the active voltage selector. 
     In another embodiment, a cleaner includes a motor for rotating a collecting fan; a battery; a voltage converter for converting an AC voltage received from a power source into a DC voltage; a motor driver for driving the motor using one of a voltage of the battery and the DC voltage depending on whether the AC voltage is received; and a forcible interrupter for temporarily disconnecting the motor driver from the motor depending on whether the AC voltage is received. 
     In further another embodiment, a method for driving a cleaner includes converting an AC voltage received from a power source into a DC voltage; actively switching a voltage of a battery and the DC voltage selectively; and driving a motor using the actively-switched voltage. 
     The method may further include detecting whether the AC voltage is received. In this case, the driving of the motor include: dropping the actively switched voltage; and generating at least two phase voltage signals to be provided to the motor, by using one of the dropped voltage and the actively switched voltage depending on the detection results for the AC voltage. 
     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are intended to provide a further understanding of the present disclosure. In the drawings: 
         FIG. 1  is a block diagram of a cleaner according to an embodiment; 
         FIGS. 2 to 4  are waveform diagrams of motor driving signals that are provided to a motor; 
         FIG. 5  is a block diagram of an embodiment of a forcible interrupter illustrated in  FIG. 1 ; 
         FIG. 6  is a waveform diagram of an I/O signal of each part in  FIG. 5 ; and 
         FIG. 7  is a block diagram of another embodiment of the forcible interrupter illustrated in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
       FIG. 1  is a block diagram of a cleaner according to an embodiment. 
     Referring to  FIG. 1 , the cleaner includes a battery  12  and an AC-DC converter  10  for converting an AC voltage into a DC voltage. The AC voltage is received from a conventional source, such as, for example, a power utility company, a power generator, or any other entity and/or device capable of generating an AC voltage. 
     The AC-DC converter  10  converts an AC voltage (e.g., 220 V), which is received from a power cord  11 , into a DC voltage. The power cord  11  transmits the AC voltage received from a voltage source (not illustrated) to the AC-DC converter  10 . When the AC voltage is provided through the power cord  11 , an output DC voltage of the AC-DC converter  10  (hereinafter referred to as “first DC voltage”) has a high voltage level of about 310 V. For this voltage conversion, the AC-DC converter  10  includes a rectifier  10 A and a smoother  10 B connected in series to the power cord  11 . The rectifier  10 A full-wave rectifies or half-wave rectifies the AC voltage received from the power cord  11 , thereby outputting a ripple voltage. The smoother  10 B smoothes the ripple voltage from the rectifier  10 A to generate the first DC voltage. To this end, the smoother  10 B includes a choke coil L 1  connected between a high-voltage line  13 A and a high-voltage output terminal of the rectifier  10 A, and a capacitor C 1  connected between the high-voltage line  13 A and a base-voltage line  13 B. The choke coil L 1  suppresses a ripple component contained in the ripple voltage that will be provided from the high-voltage output terminal of the rectifier  10 A to the high-voltage line  13 A. The capacitor C 1  is charged and discharged depending on the suppressed ripple voltage from the choke coil L 1  such that the first DC voltage of about 310 V is applied on the high-voltage line  13 A. The first DC voltage output from the smoother  10 B is provided to an active voltage selector  14 . 
     The battery  12  supplies its charged DC voltage to the active voltage selector  14 . The charged DC voltage of the battery  12  (hereinafter referred to as “second DC voltage”) has a low voltage level of about 28 to 50 V. In order to generate the second DC voltage with a low voltage level of about 28 to 50 V, the battery  12  includes about 24 to 30 charge cells. Ni-MH charge cells may be used as the charge cells of the battery  12 . 
     The active voltage selector  14  monitors whether the first DC voltage is received from the AC-DC converter  10 . Depending on whether the first DC voltage is received, the active voltage selector  14  provides one of the second DC voltage from the battery  12  and the first DC voltage from the AC-DC converter  10  to an inverter  18 A of a motor driver  18 . When the first DC voltage is not received from the AC-DC converter  10  (i.e., in a DC voltage mode), the active voltage selector  14  provides the second DC voltage from the battery  12  to the inverter  18 A of the motor driver  18 . On the other hand, when the first DC voltage is received from the AC-DC converter  10  (i.e., in an AC voltage mode), the active voltage selector  14  provides the first DC voltage to the inverter  18 A of the motor driver  18 . To this end, the active voltage selector  14  includes a unidirectional element (for example, diode D 1 ) that is connected between a high-voltage output terminal of the battery  12  and the high-voltage line  13 A (specifically, a connection node between the choke coil L 1  and a high-voltage input terminal of the inverter  18 A). When a voltage on the high-voltage line  13 A is higher than a voltage on the high-voltage output terminal of the battery  12  (i.e., in the AC voltage mode where the first DC voltage is provided to the high-voltage line  13 A), the diode D 1  is turned off to interrupt the second DC voltage to be provided from the battery  12  to the inverter  18 A. At this point, the first DC voltage is provided from the AC-DC converter  10  to the inverter  18 A. On the other hand, when a voltage on the high-voltage line  13 A is lower than a voltage on the high-voltage output terminal of the battery  12  (i.e., in the DC voltage mode where the first DC voltage is not provided to the high-voltage line  13 A), the diode D 1  is turned on to provide the second DC voltage from the battery  12  to the inverter  18 A. The active voltage selector  14  may further include an additional diode that is connected between the choke coil L 1  and the high-voltage line  13 A (specifically, a connection node between the diode D 1  and the high-voltage input terminal of the inverter  18 A). The additional diode prevents the second DC voltage from the battery  12  from leaking to the AC-DC converter  10 , thereby increasing the available time (i.e., the discharge period) of the battery  12 . 
     The cleaner further includes a detector  16  connected to the power cord  11 , and a serial circuit of a motor  20  and a collecting fan  22  connected the motor driver  18 . The detector  16  detects whether the AC voltage is supplied through the power cord  11 . Depending on the detection results, the detector  16  provides a controller  18 B of the motor driver  18  with an AC voltage detection signal ASS having one of a high logic voltage and a low logic voltage (i.e., a base voltage). When the AC voltage is supplied through the power cord  11 , the detector  16  provides the controller  18 B with an AC voltage detection signal ASS with a high logic voltage for indicating or designating the AC voltage mode. On the other hand, when the AC voltage is not supplied through the power cord  11 , the detector  16  provides the controller  18 B with an AC voltage detection signal ASS with a low logic voltage for indicating or designating the DC voltage mode. To this end, the detector  16  includes a diode for rectification and resistors for voltage division. Alternatively, the detector  16  may detect a voltage on an output terminal of the AC-DC converter  10  to determine whether the AC voltage is supplied. In this case, there may be an error in the determination by the detector  16  or the circuit configuration of the detector  16  may be complex. 
     Further alternatively, the detector  16  may be implemented using a program operating in the controller  18 B. In this case, the controller  18  may be electromagnetically connected to the power cord  11 . 
     Depending on the logic voltage levels of the AC voltage detection signal ASS from the detector  16 , the motor driver  18  drives the motor  20  in one of a pulse width modulation (PWM) mode and a pulse trigger mode. When the AC voltage detection signal ASS of a high logic voltage is received from the detector  16  (i.e., in the AC voltage mode), the motor driver  18  drives the motor  20  in a pulse trigger mode so that an average voltage provided to the motor  20  can be about 28 to 50 V that is identical to the second DC voltage from the battery  12 . That is, when the AC voltage is supplied (i.e., in the AC voltage mode), the motor driver  18  drops the first DC voltage of about 310 V from the AC-DC converter  10  to about 28 to 50 V (i.e., the second DC voltage from the battery  12 ). In this case, the period of a trigger pulse applied to the motor  20  is minutely increased/decreased depending on the rotation period (or rotation speed) of the motor  20  while the width of the trigger pulse is maintained at a constant value independent of the rotation period of the motor  20 , thereby adjusting the rotation speed (i.e., the rotational force) of the motor  20 . On the other hand, when the AC voltage detection signal ASS of a low logic voltage is received from the detector  16  (i.e., in the DC voltage mode), the motor driver  18  drives the motor  20  in a PWM mode so that the second DC voltage from the battery  12  is used, as it is, to drive the motor  20 . The rotation speed of the motor  20  may be adjusted according to the duty rate of a PWM component. When the duty rate of the PWM component increases, the rotation speed (i.e., the rotational force) of the motor  20  increases. To the contrary, when the duty rate of the PWM component decreases, the rotation speed (i.e., the rotational force) of the motor  20  decreases. In order to adjust the rotation speed (i.e., the rotation force) of the motor  20 , the motor driver  18  may respond to key switches for output selection (not illustrated). 
     In order to generate a phase voltage signal PVS of PWM mode or pulse trigger mode to be provided to the motor  20 , the motor driver  18  includes the controller  18 B for controlling an inverting operation of the inverter  18 A. Under the control of the controller  18 B, the inverter  18 A switches the selected DC voltage (i.e., the first or second DC voltage) from the active voltage selector  14  in a pulse trigger mode or a PWM mode to generate at least two phase voltage signals PVSs. In the DC voltage mode, the inverter  18 A generates at least two phase voltage signals PVSs that have a PWM component at every predetermined period (e.g., the rotation period of the motor  20 ). The phase voltage signals PVSs have a PWM component in rotation. The duty rate of the PWM component is adjusted according to the rotation speed (or the rotational force) of the motor  20 , which is set by a user. In the AC voltage mode, the inverter  18 A generates at least two phase voltage signals PVSs that have a high trigger pulse at every predetermined period (e.g., the rotation period of the motor  20 ). The high trigger pulses of the phase voltage signals PVSs have a phase difference corresponding to “the number of 360°/phase voltage signals PVSs ”. The width of the trigger pulse is fixed independently of the rotation period (or the rotation speed) of the motor  20 , while the period of the trigger pulse is minutely adjusted according to the rotation period (or the rotation speed) of the motor  20 , so that the motor  20  rotates at the speed set by the user (or generates the rotational force set by the user). 
     In response to the AC voltage detection signal ASS from the detector  16 , the controller  18 B provides the inverter  18 A with at least two phase control signals PCSs that have a PWM component in rotation or have a trigger pulse at every predetermined period (e.g., the rotation period of the motor  20 ). In the DC voltage mode where the AC voltage detection signal ASS with a low logic voltage is generated by the detector  16 , the phase control signals PCSs generated by the controller  18 B alternately have a PWM component for a predetermined period (i.e., a period corresponding to “the number of 360°/phase voltage signals PVSs”) per the rotation period of the motor  20 . The duty rate of the PWM component is adjusted according to the desired rotation speed (or rotational force) of the motor  20 . In the AC voltage mode where the AC voltage detection signal ASS with a high logic voltage is generated by the detector  16 , the phase control signals PCSs from the controller  18 B have one high trigger pulse per the rotation period of the motor  20 . The high trigger pulses contained in the phase control signals PCSs have a phase difference corresponding to “the number of 360°/phase voltage signals PVSs”. In addition, the width of the trigger pulse contained in each of the phase control signals PCSs may be fixed independently of the desired rotation speed (or rotational force) of the motor  20  while the period of the trigger pulse in each of the phase control signals PCSs may be minutely adjusted according to the desired rotation speed (or rotational force) of the motor  20 . According to an increase or decrease in the rotation period of the motor  20 , the trigger pulse with the fixed width and the minutely adjusted period changes the average level of the voltage supplied to the motor  20 , thereby increasing or decreasing the rotational force of the motor  20 . In order to generate the phase control signals PCSs, the controller  18 B responds to at least two phase sensing signals PSSs from the motor  20 . For example, the controller  18 B generates the first phase control signal PCS on the basis of the first phase sensing signal PSS and also generates the second phase control signal PCS on the basis of the second phase sensing signal PSS. For example, in the AC voltage mode, the controller  18 B controls a falling (or rising) edge of the first phase control signal PCS to coincide with a falling (or rising) edge of the first phase sensing signal PSS and also controls a falling (or rising) edge of the second phase control signal PCS to coincide with a falling (or rising) edge of the second phase sensing signal PSS. In the DC voltage mode, the controller  18 B controls the first phase control signal PCS to contain a PWM component for a high-voltage (or low-voltage) period of the first phase sensing signal PSS and also controls the second phase control signal PCS to contain a PWM component for a high-voltage (or low-voltage) period of the second phase sensing signal PSS. 
     The controller  18 B may respond to a start sensing signal and an operation sensing signal as well as to the phase sensing signals PSSs. On the basis of the start sensing signal, the controller  18 B controls the trigger pulse period and the PWM component duty rate of the phase control signals PCSs to have a great value until the motor  20  rotates at a desired rotation speed. When the rotation speed of the motor  20  reaches the desired rotation speed, the controller  18 B control the trigger pulse period and the PWM component duty rate of the phase control signals PCSs, which will be provided to the inverter  18 A, to have a value corresponding to the desired rotation speed. On the basis of the period of the operation sensing signal, the controller  18 B controls the trigger pulse period to have a value corresponding to the desired rotation speed. The phase of the operation sensing signal is earlier by 30° to 50° than the phase of the start sensing signal. The phase difference between the operation sensing signal and the start sensing signal is determined by the arrangement of a operation sensing sensor and a start sensing sensor included in the motor  20 . For example, a central processing unit (CPU) or a microcomputer may be used as the controller  18 B. 
     The motor driver  18  further includes a DC-DC converter  18 C that is connected between the battery  12  and the controller  18 B. The DC-DC converter  18 C down-converts (level-shifts) the second DC voltage of the battery  12  to a transistor logic voltage (e.g., the first DC voltage of about 5 V). The transistor logic voltage generated by the DC-DC converter  18 C is provided to the controller  18 B so that the controller  18 B can operate stably. In order to generate the transistor logic voltage stably using the second DC voltage, the DC-DC converter  18 C includes a switched-mode power supply (SMPS). Alternatively, the DC-DC converter  18 C may include a resistor-based voltage divider. 
     The motor  20  is driven by phase voltage signals PVSs from the inverter  18 A of the motor driver  18  to generate rotational force (i.e., rotational torque) that will be transmitted to the collecting fan  22 . A switched reluctance motor of at least two phases is used as the motor  20 . The switched reluctance motor  20  generates the at least two phase sensing signals PSSs. For example, two phase sensing signals PSSs are generated by the switched reluctance motor  20 . The switched reluctance motor  20  also generates the start sensing signal and the operation sensing signal as well as the phase sensing signals PSSs. The phase of the start sensing signal is later by 30° to 50° than the phase of the first phase sensing signal PSS and is earlier by 40° to 60° than the phase of the second phase sensing signal PSSs. The operation sensing signal has the same phase and period as one of the phase sensing signals. The operation sensing signal generated by the switched reluctance motor  20  has the same phase and period as the first phase sensing signal PSSs. When the voltage of the battery  12  (i.e., the second DC voltage of 28 to 50 V) is used, the switched reluctance motor  20  has at least two coils with a characteristic impedance that is low enough to rotate the motor at a desired rotation speed (or to generate a desired rotational force). For example, the first and second coils in the switched reluctance motor  20  are alternately excited by the first and second phase voltage signals PVSS. Accordingly, the switched reluctance motor  20  is rotated at a desired rotation speed (e.g., 7000 to 9000 rpm) by PWM-mode phase voltage signals PVSs as well as by trigger-pulse-mode phase voltage signals PVSs with an average voltage of 28 to 50 V, thereby generating the rotational force with a desired strength. The use of the PWM-mode phase voltage signals PVSs can solve the problem of heat that is generated when the motor  20  rotates at a speed of 7000 to 9000 rpm in the AC voltage mode. In addition, the switched reluctance motor  20  with the low-characteristic-impedance coils is rotated at a desired speed by the phase voltage signal PVS of a PWM component, thereby making it possible to generate a desired rotational force by the voltage of the battery  12  as well as by the AC voltage. 
     The collecting fan  22  is rotated by the rotational force (or rotational torque) of the motor  20  to generate inhalation (suction) force. This inhalation force causes pollutant particles (e.g., dust and dirt) to be collected into the collecting space (not illustrated) of the cleaner. The rotational force with a desired strength is supplied from the switched reluctance motor  20  with the low-characteristic-impedance coils by using the voltage of the battery  12  as well as by using the AC voltage. Accordingly, the collecting fan  22  can generate the inhalation force with a desired strength by using the voltage of the battery  12  as well as by using the AC voltage, thereby making it possible to reduce the time taken to clean up pollutant particles using the voltage of the battery  12  to about the time taken to clean up the pollutant particles using the AC voltage. 
     The cleaner further includes a charger  24  connected between the power cord  11  and the battery  12 , and a forcible interrupter  26  connected between the controller  18 B and the inverter  18 A. In the AC voltage mode where the AC voltage is supplied through the power cord  11 , the charger  24  performs a rectifying/smoothing operation to convert the AC voltage into a DC voltage. In addition, the charger  16  supplies the DC voltage to the battery  12  to charge the battery  12 . 
     On the basis of the AC voltage detection signal ASS from the detector  16 , the forcible interrupter  26  detects the time point when the first DC voltage converted from the AC voltage starts to be used instead of the second DC voltage of the battery  12 . During a predetermined time from the time point when the first DC voltage converted from the AC voltage starts to be used instead of the second DC voltage of the battery  12 , the forcible interrupter  26  interrupts at least two phase control signals PCSs to be provided from the controller  18 B to the inverter  18 A, outputting a forcible interrupt phase control signal SPCS so that the phase voltage signal PVS is not provided from the inverter  18 A to the switched reluctance motor  20 . Accordingly, the switched reluctance motor  20  is not driven during the predetermined time from the time point when the first DC voltage converted from the AC voltage starts to be used instead of the second DC voltage of the battery  12  (i.e., the time point of change from the DC voltage mode into the AC voltage mode). As illustrated in  FIG. 2 , from the time when the AC voltage is supplied from a time point T 1 , the first DC voltage from the AC-DC converter  10 , instead of the second DC voltage of the battery  12 , is provided to the inverter  18 A. During a predetermined period from the time point T 1  to a time point T 2 , the forcible interrupter  26  interrupts at least two phase voltage signals PCSs to be provided from the controller  18 B to the inverter  18 A, so that the phase voltage signal PVS is not provided to the switched reluctance motor  20 . From the time point T 2 , the forcible interrupter  26  provides at least two phase control signals PCSs from the controller  18 B to the inverter  18 A such that the switched reluctance motor  20  is driven by at least two phase voltage signals PVSs. In addition, the switched reluctance motor  20  is driven by the phase voltage signal PVSs of a PWM component till the time point T 1  as illustrated in  FIG. 3 , while it is driven by the phase voltage signal PVS of a trigger pulse after the time point T 2  as illustrated in  FIG. 4 . This is to prevent the first DC voltage (converted from the AC voltage) from being Inverted by the PWM-mode phase voltage signal PVS because the controller  18 B is late in detecting the time point of change from the DC voltage mode into the AC voltage mode. In result, the generation of the phase voltage signal PVS of an excessively-high voltage, which may be generated during a predetermined period from the time point of change from the DC voltage mode into the AC voltage mode, is suppressed to prevent damage to the low-characteristic-impedance coils of the switched reluctance motor  20 . 
       FIG. 5  is a block diagram of an embodiment of the forcible interrupter  26  illustrated in  FIG. 1 . 
     Referring to  FIG. 5 , the forcible interrupter  26  includes a comparator  30 , a monostable pulse generator  32 , and a control switch  34 . 
     The comparator  30  compares the AC voltage detection signal ACC from the detector  16  ( FIG. 1 ) with a predetermined reference voltage (not illustrated) to generate a mode switch signal MSS. The mode switch signal MSS has a high logic level while the AC voltage is being supplied to the power cord  11 , but has a low logic level while the AC voltage is not being supplied to the power cord  11 . As illustrated in  FIG. 6 , in synchronization with the mode switch signal MSS, the active voltage selector  14  ( FIG. 1 ) alternately selects the DC voltage of the battery  12  and the first DC voltage converted from the AC voltage. 
     The monostable pulse generator  32  generates a gate control signal GCS with a gate pulse of a low (or high) logic level during a predetermined period from a rising edge of the mode switch signal MSS (i.e., the time point T 1  when the AC voltage is supplied) to the time point T 2 . The width of the gate pulse in the gate control signal GCS is preset by the manufacturer to the extent that the user cannot detect the stop of the switched reluctance motor  20 . 
     Depending on the logic value of the gate control signal GCS from the monostable pulse generator  32 , the control switch  34 , which outputs an SPCS control signal, interrupts at least two phase control signals PCSs from the controller  18 B ( FIG. 1 ) or provides the same to the inverter  18 A ( FIG. 1 ). For example, during the period of a logically-low gate pulse in the gate control signal GCS (i.e., the time period from the time point T 1  to the time point T 2 ), the control switch  34  interrupts at least two phase control signals to be provided from the controller  18 B to the inverter  18 A. Accordingly, as in MSO of  FIG. 6 , during the predetermined period (T 1 -T 2 ) from the time point T 1  (when the AC voltage starts to be supplied to the power cord  11 ) to the time point T 2 , the switched reluctance motor  20  is in a standby (SB) mode where it is not driven. This SB mode is to prevent the first DC voltage (converted from the AC voltage) from being inverted by the PWM-mode phase voltage signal PVS because the controller  18 B is late in detecting the time point of change from the DC voltage mode into the AC voltage mode. In result, the generation of the phase voltage signal PVS of an excessively-high voltage, which may be generated during a predetermined period from the time point of change from the DC voltage mode into the AC voltage mode, is suppressed to prevent damage to the low-characteristic-impedance coils of the switched reluctance motor  20 . 
       FIG. 7  is a block diagram of another embodiment of the forcible interrupter  26  illustrated in  FIG. 1 . The forcible interrupter of  FIG. 7  is similar to the forcible interrupter of  FIG. 5  with the exception that it includes a logic operation unit  40  instead of the monostable pulse generator  32 . A description of the same components as in  FIG. 5  will be omitted for simplicity of description. 
     The logic operation unit  40  receives a mode switch recognition signal MSRS from the controller  18 B ( FIG. 1 ) as well as the mode switch signal MSS from the comparator  30 . The controller  18 B generates the mode switch recognition signal MSRS by determining the supply period of the AC voltage on the basis of the AC voltage detection signal ASS from the detector  16 . That is, because the controller  18 B performs a logic operation, it generates the mode switch recognition signal MSRS by detecting the time point when the AC voltage starts to be supplied, after the elapse of the predetermined period (T 1 -T 2 ). Using the mode switch signal MSS and the mode switch recognition signal MSRS, the logic operation unit  40  generates the gate control signal GCS for setting the period of the SB mode, as illustrated in  FIG. 6 . To this end, the logic operation unit  40  exclusive-ORs or exclusive-NORs the mode switch signal MSS and the mode switch recognition signal MSRS, and ORs or ANDs the result and one of the mode switch signal MSS and the mode switch recognition signal MSRS. 
     Then, during the period of a logically-low gate pulse in the gate control signal GCS from the logic operation unit  40  (i.e., the period from the time point T 1  to the time point T 2 ) the control switch  34  interrupts at least two or more signals to be provided from the controller  18 B to the inverter  18 A. Accordingly, as in MSO of  FIG. 6 , during the predetermined period (T 1 -T 2 ) from the time point T 1  (when the AC voltage starts to be supplied to the power cord  11 ) to the time point T 2 , the switched reluctance motor  20  is in a standby (SB) mode where it is not driven. This SB mode is to prevent the first DC voltage (converted from the AC voltage) from being inverted by the PWM-mode phase voltage signal PVS because the controller  18 B is late in detecting the time point of change from the DC voltage mode into the AC voltage mode. In result, the generation of the phase voltage signal of an excessively-high voltage, which may be generated during a predetermined period from the time point of change from the DC voltage mode into the AC voltage mode, is suppressed to prevent damage to the low-characteristic-impedance coils of the switched reluctance motor  20 . 
     As described above, the cleaner according to the present disclosure actively selects the voltage of the battery and the DC voltage converted from the AC voltage and drives the switched reluctance motor by the selected voltage. Accordingly, the cleaner according to the present disclosure can automatically switch the AC voltage mode and the DC voltage mode and can increase the convenience of the user. 
     The cleaner according to the present disclosure uses the switched reluctance motor that has the sufficiently-low characteristic impedance to generate the desired rotational force by the voltage of the battery. Also, in the AC voltage mode where the AC voltage is supplied, the cleaner according to the present disclosure drops the DC voltage of about 310 V to about 28 to 50 V (i.e., the voltage of the battery) and supplies the same voltage to the switched reluctance motor. Accordingly, the switched reluctance motor can generate the desired rotational force by the voltage of the battery as well as by the AC voltage. Likewise, the collecting fan can generate the inhalation force with the desired strength by using the voltage of the battery as well as by using the AC voltage. Consequently, the cleaner according to the present disclosure can have the sufficiently-high capability of collecting pollutant particles and can reduce the time taken to clean up pollutant particles using the voltage of the battery  12  to about the time taken to clean up the pollutant particles using the AC voltage. 
     In addition, the cleaner according to the present disclosure goes through the temporary stop mode for preventing the excessively-high voltage from being applied to the low-characteristic-impedance motor, before entry into the AC voltage mode. Accordingly, the cleaner according to the present disclosure can interrupt the excessive voltage driving that may occur in the switching operation between the AC voltage mode and the DC voltage mode, thereby making it possible to prevent the occurrence of breakdown, malfunction and component damage. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 
     The present disclosure relates to subject matter contained in Korean Patent Application No. 10-2007-0053851, filed Jun. 1, 2007, the disclosure of which is expressly incorporated herein by reference, in its entirety.