KR20020033050A - Motor control device of electric-powered reel - Google Patents

Abstract

PURPOSE: To improve the operability and prevent a device defective from occurring even when a maloperation is carried out in a motor controller for an electric reel capable of controlling a motor at a voltage of power supply or above. CONSTITUTION: The motor controlling part 20 of the electric reel is capable of controlling the acceleration and deceleration of the motor 12 for the electric reel and connected to a speed changing operation part SK, a PWM driving circuit 31 and a booster circuit 32. The speed changing operation part SK is used to set the rotational speed of the motor 12. The PWM driving circuit 31 is capable of changing the voltage applied from a power source 40 according to the speed set with a speed setting means by a duty signal DS from the reel controlling part 20. The booster circuit 23 is capable of amplifying the transformed voltage to a voltage of the power supply or above according to the set specific speed.

Description

Motor control device of electric-powered reel

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control apparatus, in particular a motor control apparatus of an electric reel for increasing and decreasing the motor of an electric reel.

Electric reels that can rotate the spool at the time of winding the fishing line by the motor are often used when fishing on the boat, for example, fish having a depth of 100 m or more. Such electric reels generally have a duty control means, By operating the shifting switch provided in the operation part of the electric reel, the duty is changed to change the fishing line winding speed.

Such duty control of the electric reel is usually performed within a range of a voltage supplied by the power supply (hereinafter referred to as a power supply voltage), but the voltage can be boosted above the power supply voltage to rotate the spool at high speed. Thus, the electric reel which boosts a voltage is disclosed by the Japanese Utility Model Registration No. 256811, for example. Here, the shifting switch is operated to wind the fishing line at a voltage lower than the power supply voltage, and at light load such as when the fishing hook is collected, the boosting switch is operated to boost the voltage using a boosting coil to open the fishing line at high speed. Winding up.

In the above-mentioned conventional electric reel, the shift switch and the boosting switch are made separate switches, and the angler (operator) performs the boosting operation separately from the spool increase and decrease operation. However, it is poor in operability to install a switch for boosting up separately from the shift switch to allow the angler to operate. The angler must also determine whether it is in a state where the boost switch can be operated. Specifically, it is recognized that the boosting switch should be operated when the bait is replaced or the fish is missed. The finger is switched from the shifting switch to the boosting switch to wind the fishing line. However, if the boost switch is operated under high load, such as when a fish is drawn in by mistake, a high voltage may be applied to the boost coil, resulting in damage to the boost coil, resulting in device failure.

An object of the present invention is to improve the operability in a motor control apparatus of an electric reel capable of controlling a motor at a voltage equal to or higher than a power supply voltage, and to prevent device defects from occurring even when incorrect operation is performed.

BRIEF DESCRIPTION OF THE DRAWINGS The top view of the electric reel which employ | adopted one Embodiment of this invention.

2 is a plan view of the depth display unit.

3 is a block diagram showing the configuration of a control system.

4 is a flowchart showing a main routine.

5 is a flowchart showing a key input subroutine.

6 is a flow chart illustrating a learning mode subroutine.

7 is a flowchart showing a designated line learning processing subroutine.

8 is a flowchart showing each operation mode subroutine.

[Short description of symbols]

10 spools

12 motor

30 reel control unit

31 PWM drive circuit

32 booster circuit

50 conductor

51, 52 capacitors

SK shift control panel

The motor control apparatus of the electric reel which concerns on this invention 1 is an apparatus which increases and decreases a motor of an electric reel, and is provided with a speed setting means, a transmission means, and a boost means. The speed setting means is a means for setting the rotational speed of the motor. The speed change means is a means for changing the voltage applied from the power source in accordance with the speed set by the speed setting means. The boost means is means for amplifying the transformed voltage above the voltage of the power supply according to a specific speed set by the speed setting means.

In this motor control device, when the rotational speed is set by the speed setting means, the speed changing means changes the voltage in accordance with the set speed. For example, the voltage is changed to maintain the speed, or the motor is controlled by the voltage related to the speed. When the specific speed is set by the speed setting means, the boost means amplifies the transformed voltage above the voltage of the power supply, and the motor is driven at high speed by the amplified voltage.

In this case, when a specific speed is set, the voltage is amplified above the power supply voltage, so that high-speed winding can be performed without performing other operations and the operability is improved. In addition, since the voltage is increased by amplification rather than the voltage boosted by the coil, even when the coil is used, the voltage is not applied to the coil itself so much that the device failure does not occur even if it is misoperated. In addition, in the boosting using the boosting coil, even if the voltage is increased, the current value does not increase so much that the effect of the speed increase cannot be expected very much. However, in the present invention, since the voltage is increased by amplification, the current is also amplified and the effect of speed increase is very high.

In the motor control apparatus for an electric reel according to the second aspect of the invention, in the apparatus according to the first aspect, the speed changing means converts a DC voltage applied from a power source into an AC voltage having at least a frequency changed in accordance with the speed set by the speed setting means, The boost means amplifies the AC voltage by resonating with the AC voltage of the specific frequency converted according to the set specific speed. In this case, since the voltage is amplified by resonating with respect to a specific frequency, the resonance frequency can be arbitrarily set by the resonant circuit.

The motor control apparatus for an electric reel according to the third aspect of the invention is the apparatus according to the second aspect, wherein the shifting means controls the shift by controlling the pulse width by changing the duty ratio by a variable switching frequency with a direct current voltage supplied from a power source, and boosting means. Resonates at a specific frequency among the variable switching frequencies used in the pulse width modulation. In this case, since the switching frequency is made variable at the time of pulse width modulation and is resonated by the specific frequency, high-precision motor control by PWM control and amplification by resonance can be easily achieved.

The motor control apparatus for an electric reel according to the fourth aspect is the apparatus according to any one of the first to third aspects, wherein the boosting means has an LC resonant circuit including a coil and a capacitor. In this case, the boost means can be simply configured by the LC resonant circuit.

In FIG. 1, the electric reel which employ | adopted one Embodiment of this invention is a reel driven by the electric power supplied from the external power supply. In addition, the electric reel is a reel having a depth display function for displaying the depth of the fishing hook according to the fishing line discharge length or fishing line winding length.

The electric reel is attached to the reel main body 1 which can be attached to the fishing rod R, the handle 2 for spool rotation arrange | positioned at the side of the reel main body 1, and the reel main body 1 side of the handle 2. Mainly provided with the drag drag star drag 3 arranged.

The reel unit 1 includes a frame 7 composed of a pair of left and right side plates 7a and 7b and a plurality of connecting member materials 7c connecting them, and a left and right side cover 8a covering left and right sides of the frame 7. , 8b) and a front cover 9 covering the front portion of the frame 7.

The rotation shaft of the handle 2 is rotatably supported by the side cover 8b on the handle 2 side. The lower part of the back connection member 7c is provided with the main-body connector part 19 for connecting one end of the power cord 18. As shown in FIG. One end of the power cord 18 is provided with a cord connector 18a detachably attached to the main body connector 19, and the other end is connected with an external power supply 40 made of, for example, a 12 volt lead acid battery. have. The power of the external power supply 40 is supplied to the reel via the main body connector portion 19. The external power supply 40 is, for example, a 12 volt lead acid battery.

Inside the reel unit 1, a spool 10 connected to the handle 2 is rotatably supported. Inside the spool 10, a direct current drive motor 12 for rotating the spool 10 in the fishing line winding direction is disposed. Further, inside the reel unit, a level wind mechanism, a magnet wheel (not shown), a rotation transmission mechanism (not shown), a clutch mechanism (not shown), and the like are provided.

The rotation transmission mechanism includes a planetary gear mechanism for slowing the rotation of the motor 12, a reverse rotation prevention mechanism for preventing the reverse rotation of the handle 2, and a drag mechanism for braking the rotation in the fishing line discharge direction of the spool 10. The rotation of the handle 2 is transmitted to the spool 10, and the rotation of the motor 12 is transmitted to the spool 10. The clutch mechanism turns on / off the drive transmission between the handle 2 and the motor 12 and the spool 10. Moreover, the clutch lever 11 for on / off operation of a clutch mechanism is arrange | positioned at the side surface of the handle 2 side of the reel main body 1. As shown in FIG.

A watertight counter case 4 is fixed to the upper portion of the reel unit 1. As shown in detail in FIG. 2, the counter case 4 includes a depth display section 5 made up of a liquid crystal display for displaying the depth of the fishing hook and the fish habitat layer based on two standards of water surface / bottom; Various operation key portions 6 arranged around the display portion 5 are provided.

The depth display section 5 is a depth display region 5a of four-digit seven-segment display arranged at the center, a three-digit bottom depth display region 5b disposed below the depth display region 5a, and the depth display region 5a. 4 includes a gear shift display area 5c disposed on the right side. In the shift stage display area 5c, the number of stages of the fishing line winding speed set by the shift operation unit SK is displayed on a bar graph.

In the depth display part 5, eight kinds of character strings of "from bottom", "100m", "200m", "body diameter use", "a designated line", "fishing line release stop", "0 set" can be displayed The character string "from the bottom" is displayed when the depth display mode is in the bottom mode. The mode from the bottom is a mode in which the depth of the fishing hook is displayed on the basis of the bottom, and is mainly used when fishing a fish that lives on the bottom. In addition, the depth of the fishing hook is usually expressed on the surface basis (mode from surface).

The characters from "100m" to "designated line" indicate the type of learning mode, and if any one is selected alternatively, only the character string of the selected learning mode is displayed.

The operation key unit 6 is disposed below the shift operation unit SK and the shift operation unit SK having the speed increase button SK1 and the deceleration button SK2 arranged side by side up and down on the right side of FIG. 1 of the depth display unit 5. Has a motor button (PW). The operation key portion also has a attracting button IB, a fish habitat layer memo button TB, and a mode button MD arranged on the left side up and down.

The motor button PW is a button for turning on / off the motor 12.

The speed increase button SK1 of the shift operation section SK is a button for speeding up the driven motor 12, and the deceleration button SK2 is a switch for deceleration. When the speed increase button SK1 of the shift operation unit SK is operated, the shift stage increases by one step according to the operation time. In addition, when the deceleration button SK2 is operated, the speed change step is reduced by one step. When the shift stage is changed, the duty ratio, which is the reference for PWM control, changes accordingly. For example, 30% in the first stage, 50% in the second stage,... In the seventh stage, it changes to 95%.

A lure button IB is a button used to set a lure mode for attracting a hook of fish in the vicinity of a fish habitat, to conduct lure learning, or to release a lure mode. The fish layer memo button TB is a button for setting the position of the upper fish layer when in mode from the surface or the bottom layer of fish layer when in mode from the bottom. Press and hold for 3 seconds or longer to set the depth indication to O.

The mode button MD is a switch for setting four types of learning modes. For example, when it is pressed once, it is set to the 100m learning mode, and when it is pressed twice in succession, the 200m learning mode is pressed, and when it is pressed three times in succession, the learning mode using If you press the button 4 times in succession, each learning mode is set as the designated line learning mode.

Here, the 100m learning mode and the 200m learning mode are used when winding the spool 10 on a commercially available fishing line in 100m units whose length is already known as 100m or 200m and whose thickness or winding start diameter is unknown. Learning mode. In these two learning modes, the correlation between the spool rotation at the end of the fishing line winding and the fishing line length per spool is learned, and the spool rotation over the entire length of the fishing line and one time according to the learning result. Find the relationship with the length of the hall.

The body diameter utilization learning mode is a learning mode used when winding up the spool 10 with the fishing line whose length, thickness (lake), and winding start diameter are unknown. In the learning mode using the body diameter, the correlation between the number of spool rotations at the start of the fishing line winding and the end of the fishing line winding and the length of the fishing line per one spool is learned. Find the relationship between the number of spool revolutions over and the length of the fishing line per revolution.

The designation line learning mode is a mode used when the designated thickness (lake) and the long fishing line prepared in the storage unit 24 are wound on the spool 10.

In the counter case 4, as shown in FIG. 3, the depth display part 5 and the reel control part 20 which perform display control and motor control are arrange | positioned. In the counter case 4, a PWM drive circuit 31 for PWM driving the motor 12 is disposed.

The reel control unit 20 includes a microcomputer including a CPU, a RAM, a ROM, an I / 0 interface, and the like disposed in the counter case 4. The reel control unit 20 executes various control operations such as display control and motor drive control of the depth display unit 5 in accordance with the control program. The reel control unit 20 is connected to various buttons of the operation key unit 6, a spool sensor 21, and a spool counter 23 for detecting the rotation direction and the rotation speed of the spool 10. The reel control unit 20 is also connected with a buzzer 22 for outputting various alarms, a PWM drive circuit 31, a depth display unit 5, a storage unit 24, and another input / output unit.

The PWM drive circuit 31 includes the FET 41 as a drive element for driving the motor 12. The PWM drive circuit 31 is controlled by the duty signal DS different in frequency and amplitude output from the reel control unit 20 to variably drive the speed of the motor 12. Between the PWM drive circuit 31 and the motor 12, a booster circuit 32 is provided which resonates at a specific frequency of the duty signal DS to amplify a voltage and a current.

As shown in FIG. 4, the PWM drive circuit 31 is mainly comprised by the switching transistor which consists of the FET 41, and turns on / off a power supply voltage by the duty signal DS given to the gate. The drain of the FET 41 is connected to the power supply 40 via the booster circuit 32, and a source is provided.

The booster circuit 32 includes an inductor (L) 50 disposed between the power supply 40 and the FET 41, and capacitors C1 and C2 51 having one end connected to both ends of the inductor 50. 52, a diode D1 having an anode connected to one end of the capacitor 52, a cathode connected to the other end of the capacitor 51, and an anode connected to the other end of the capacitor 51, and a cathode connected to the capacitor 52. It has a diode (D2) 54 connected to the other end. The motor 12 is connected to the other end of the capacitor 52.

The booster circuit 32 amplifies the voltage applied to the motor 12 switched from the FET 41 by resonating at the resonance frequency f = 1 / (2π (LC) ^1/2 ). Where L is the inductance of the inductor 50, and C is the combined capacitance ((C1 · C2) / (C1 + C2)) of the capacitors 51, 52 connected in series with the inductor 50. Specifically, if the voltage applied to the motor 12 which is changed by the duty signal DS whose frequency and pulse width change in accordance with the set speed coincides with the resonance frequency, it is amplified. Here, for example, the applied voltage is amplified by resonating at a frequency of 95% duty.

The PWM drive circuit 31 and the booster circuit 32 operate as follows. As shown in FIG. 5, the duty signal DS according to the shift stage set by the operation of one of the buttons SK1 and SK2 of the shift operation unit SK from the reel control unit 20 is shown in FIG. 5. Is given, the voltage along the pulse width is applied to the motor 12 through the diodes 53 and 54. In addition, the duty signal is set by software control described later in accordance with the set shift stage. Since the speed varies depending on the load, the pulse width (duty ratio) of the duty signal is actually increased or decreased in accordance with the detected spool speed.

For example, when the duty signal DS having a 95% duty is output from the reel controller 20, the conductor 50 and the capacitors 51 and 52 are LC-resonated to form a voltage waveform as shown in FIG. That is, in the conductor 50, when the duty signal DS is turned off, back electromotive force of about 5 V is generated, and the electric charge stored in the capacitor 51 and the capacitor 52 overlaps with it and acts on the motor 12. . When the duty signal DS is turned on, a voltage corresponding to the duty ratio acts on the motor 12. As a result, a voltage higher than the power supply voltage is generated as a whole, and the motor 12 is driven to rotate. At this time, since the current is also amplified by the resonance in the booster circuit 32, the speed increase effect is further enhanced.

The spool sensor 21 is comprised by the two reed switches 21a and 21b arrange | positioned side by side back and forth as shown in FIG. The reed switches 21a and 21b detect the magnet attached to the magnet wheel. The rotation speed of the spool 10 can be detected by counting this detection pulse with the spool counter 23. In addition, the direction of rotation of the spool 10 can be detected depending on which reed switch 21a, 21b first generated a detection pulse.

The spool counter 23 is a counter that counts the number of times the spool sensor 21 is turned on and off, and the rotation position data relating to the spool rotation speed is obtained by this count value SP. The spool counter 23 decreases the count value when the spool 10 rotates forward (rotation in the fishing line discharge direction) and increases when the spool 10 rotates backward.

The storage unit 24 is formed of a nonvolatile memory such as an EEPROM, for example, and stores data of the learning result, various data used for calculating the fishing line length, and the like.

Next, the specific control process by the software performed by the reel control part 20 is demonstrated according to the control flowchart of FIG.

When the electric reel is connected to the external power supply 40 via the power cord 18, initial setting is performed in step S1 of FIG. In this initial setting, the count value of the spool counter 23 is reset, various variables and flags are reset, or the depth display mode is set from the surface to the mode.

Next, in step S2, display processing is performed. In the display process, various display processes such as water depth display are performed. Here, in the case of the mode from the water surface, the depth of the sleep reference is displayed in the depth display area 5a.

In step S3, it is determined whether any button of the operation key part 6 was pressed. In step S4, it is determined whether or not the spool 10 is rotating. This determination is judged by the output of the spool sensor 21. In step S5, it is determined whether other commands or inputs have been made.

If key input is made, the process proceeds from step S3 to step S6 to execute key input processing. If rotation of the spool 10 is detected, the process proceeds from step S4 to step S7. In step S7, each operation mode process is executed.

If any other command or input is made, the process moves from step S5 to step S8 to execute other processing.

In the key input process of step S6, it is determined whether the fishing line winding mode is set in step S11 of FIG. This determination is made according to whether or not the mode switch MD is pressed. In step S12, it is determined whether the motor switch PW is depressed. In step S13, it is determined whether the speed increase switch SK1 of the speed change operation part SK is pressed. In step S14, it is determined whether the deceleration switch SK2 of the shift operation unit SK is pressed. In step S15, it is determined whether other switches have been operated. Other switch operations include operations such as fish habitat memo switch (TB), long press operation of each switch, and the like.

When the mode switch MD is pressed, the process proceeds from step S11 to step S16. In step S16, a fishing line winding mode process is performed. As described above, this fishing line winding mode is a 100m learning mode, a 200m learning mode, a body diameter utilization learning mode, and a designation line learning mode.

When motor switch PW is pressed, it will transfer to step S17 from step S12 of FIG. In step S17, the motor control process is executed.

When the speed increase switch SK1 is pressed, the flow advances from step S13 to step S18. In step S18, it is determined whether the shift stage SC is seven gears, that is, whether it is the normal maximum speed. If the shift stage SC is already seven, no processing is performed. In this seven stage, the duty ratio is set to 95%. When the duty ratio is set to 95%, the booster circuit 32 resonates as described above, and the voltage applied to the motor 12 is boosted to a power supply voltage (for example, 12V) or more (for example, 15 to 16V). At this time, since the voltage is increased by resonance, the current also increases with the voltage, and the speed increase effect is clearly obtained. If the shift stage SC is less than seven stages, the flow shifts from step S18 to step S19 to raise the shift stage SC one by one. In step S20, the duty ratio of the PWM drive circuit 44 is raised so as to have a speed corresponding to each shift stage SC, and the spool 10 is rotated at a speed corresponding to the set shift stage SC.

When the deceleration switch SK2 is pressed, the flow advances from step S14 to step S21. In step S21, it is determined whether the gear stage SC is one gear, that is, whether it is a normal minimum speed. If the gear stage SC is already one gear, no processing is performed. In the case where the shift stage SC is two or more stages, the flow shifts from step S21 to step S22, and the shift stage SC is lowered one by one. In step S22, the duty ratio of the PWM drive circuit 44 is lowered to have a speed corresponding to each shift stage SC, and the spool 10 is rotated at a speed corresponding to the set shift stage SC.

However, since the speed is prevented from changing between the two stages and the sixth stage, when the spool rotational speed changes, the speed increases and decreases slightly from the reference duty ratio. Even if the duty ratio is increased, the maximum duty ratio is limited to 90%. For this reason, it is not accelerated by the booster circuit 32 in 2nd-6th stage.

If another switch input is made, the process proceeds from step S15 to step S24, and performs other key input processing according to the operated key input, for example, setting the fish habitat layer value of the current depth.

In each operation mode process of step S7, it is determined in step S31 of FIG. 8 whether the rotation direction of the spool 10 is a fishing line discharge direction. This determination is judged according to which reed switch 21a, 21b of the spool sensor 21 has generate | occur | produced the pulse first. If it is determined that the rotation direction of the spool 10 is the fishing line discharge direction, the flow proceeds from step S31 to step S32. In step S32, the spool rotation speed X is decreased by one. In step S33, the data stored in the storage unit 24 is read from the spool rotational speed X every time the predetermined rotational speed decreases, and the length of the fishing line discharged is calculated and the depth LX is calculated from the fishing line length. do. In step S34, it is determined whether the obtained water depth LX coincides with the fish habitat layer position, that is, whether the fishing needle bundle has reached the fish habitat layer. The fish habitat layer position is set in the storage unit 24 by pressing the fish habitat layer memo button TB when the fish hook reaches the fish habitat layer as described above. In step S35, it is determined whether or not it is another mode. If it is not in another mode, it returns to the main routine after completing each operation mode processing.

If the water depth matches the fish habitat layer, the process proceeds from step S34 to step S36, and the buzzer 22 is sounded to indicate that the fishhook reaches the fish habitat. In the case of another mode, the flow advances from step S35 to step S37 to execute another designated mode.

If it is determined that the rotation of the spool 10 is the fishing line winding direction, the process proceeds from step S31 to step S42. In step S42, the rotation speed of the spool is increased by one.

In step S43, the data stored in the storage unit 24 is read from the spool rotation speed X each time it increases, the length of the wound fishing line is calculated, and the water depth LX is calculated again. In step S44, it is determined whether the water depth coincides with the stop position of the boat edge. If the fishing line is not wound up to the boat edge stop position, the process returns to the main routine.

When the double edge stop position is reached, the process proceeds from step S44 to step S45. In step S45, the buzzer 22 is sounded to indicate that the fishing needle bundle is at the edge of the boat. In step S46, the motor 12 is turned off. As a result, when the fish is caught, the fish is placed in a position that is easy to pick up. This ship edge stop position is set, for example, when the spool 10 is stopped for more than a predetermined time within a depth of 6 m.

Here, when the shift stage is set to seven stages, the booster circuit 32 resonates by the frequency of the duty signal DS, and the power supply voltage is amplified. For this reason, when a load is comparatively small, such as the collection of a fishing needle bundle, a fishing line can be wound up at high speed and hand movement can be made quick. In addition, since the high-speed winding is not made except in the seventh stage, it is difficult to accidentally increase the speed when the load is high. Moreover, since it can amplify by operation of the shift operation part SK, speed increase operation by the voltage more than a power supply voltage is easy. In addition, since the voltage is increased by the resonance by the booster circuit 32, the current is also amplified to clearly increase the speed increase effect. In addition, even if the conductor 50 is installed in the booster circuit 32, since the voltage does not act on the conductor itself, the case where the conductor 50 is burned and damaged is not easily generated.

[Other Examples]

(a) In the above embodiment, the frequency of the duty signal used in the PWM control is amplified by changing the frequency, but the duty signal changes only the amplitude according to the shift stage, and separately generates a frequency signal that changes according to the shift stage, for example. It may be configured to resonate and amplify in seven stages.

(b) In the above embodiment, the conductor 50 is provided in the booster circuit 32. However, when the conductor component of the motor is used as part of the resonant circuit, the conductor is unnecessary in the booster circuit. In this case, it is possible to simplify the configuration of the booster circuit and to reduce heat generation prevention.

(c) Although the motor is controlled by PWM control in the above embodiment, the present invention is not limited to this, and can be applied to all motor control methods for changing the frequency in accordance with the speed.

In the motor control apparatus of the electric reel according to the present invention, when a specific speed is set, the voltage is amplified above the power supply voltage, so that high-speed winding can be performed without performing other operations and the operability is improved. In addition, since the voltage is increased by amplification rather than boosting by the coil, even if the coil is used, the voltage is not applied to the coil itself so much that the device is not easily defective even if it is misoperated. In addition, in the boosting using the boosting coil, even if the voltage is increased, the current value does not rise so much that the effect of the increase in speed cannot be expected. However, in the present invention, since the voltage is increased by amplification, the current is also amplified and the effect of speed increase is very high.

Claims (4)

As a motor control device of the electric reel to increase and decrease the motor of the electric reel by the power from the power source, Speed setting means for setting a rotational speed of the motor; Shifting means for changing the voltage applied from the power source in accordance with the speed set by said speed setting means; And a boosting means for amplifying the transformed voltage above the voltage of the power supply according to a specific speed set by the speed setting means. The method of claim 1, The shift means converts a DC voltage applied from the power supply into an AC voltage having at least a frequency changed in accordance with the speed set by the speed setting means, And said boosting means resonates with respect to an AC voltage of a specific frequency converted according to said set specific speed to amplify said AC voltage. The method of claim 2, The shift means controls the shift by controlling the pulse width by changing the duty ratio of the DC voltage supplied from the power source by a variable switching frequency, And said boost means resonates at a specific frequency of said variable switching frequencies used in said pulse width modulation. 4. The motor control apparatus according to any one of claims 1 to 3, wherein said boosting means has an LC resonant circuit including a coil and a condenser.