JP2001196157A - Turntable motor driving circuit for direct current microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turntable motor driving circuit for a direct current microwave oven in order to apply a low cost alternating current motor as a turntable motor. SOLUTION: The turntable motor driving circuit for a direct current microwave oven comprises a control means 54 generating drive control pulse which converts the direct current voltage into alternating current voltage responding to the start input of a cooking function; and inverter means 56, 58, to which a drive control pulse is applied from the control means, converting direct current voltage of direct current power source into alternating current voltage; and a transformation means 60 transforming the alternating current voltage converted by the means of inverter into the voltage necessary to drive a motor; and a turntable motor 62, driven and rotates by alternating current, depending on the impression of the alternating current voltage transformed by the transformation means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC microwave oven turntable motor driving circuit, and more particularly, to a general-purpose AC power source for a DC microwave oven that drives a magnetron by converting a DC voltage into a high AC voltage. The present invention relates to a DC microwave oven turntable motor drive circuit for using a motor for a turntable drive motor.

[0002]

2. Description of the Related Art As is well-known, a microwave oven employed for electronic heating / cooking of food uses a magnetron to generate microwaves of about 2450 MHz per second, thereby producing the food molecules to be cooked. Array direction is 1
The desired food can be heated / cooked by frictional heat generated by vibration generated by converting hundreds of thousands of times per second.

[0003] In this microwave oven, a rated commercial AC power is boosted to a high voltage of about 2 KV by a high-voltage transformer, and then boosted to a high voltage of 4 KV by a booster circuit and applied to a magnetron. To generate microwaves.

FIG. 1 is a circuit diagram showing a circuit configuration of a conventional power supply device for an AC microwave oven. The power supply device for an AC microwave oven according to FIG. 1 is a main switch (Primary Switch). ) 10 and door lamp 12
, Fan motor 16 and turntable motor 20
, First to third relay switches 14, 18, 22, a high voltage transformer 24, a high voltage capacitor HVC, a high voltage diode HVD, and a magnetron MGT.

The main switch 10 is turned on by the closing operation of the cooking chamber door, and applies an AC voltage from a commercial AC power supply AC to the primary coil 24a of the high voltage transformer 24.

When the cooking chamber door is opened and the door detecting switch (not shown) is turned off while the first relay switch 14 is turned on in reverse, the commercial lamp is turned on. Lighting operation is performed by applying power AC.

[0007] The fan motor 16 is provided for ventilation of the cooking chamber and for preventing heat generation of the magnetron MGT during the cooking function. The fan motor 16 is supplied with a commercial AC power source AC when the second relay switch 18 is switched on in response to a predetermined cooking function being performed while the main switch 10 is switched on. It is driven to rotate.

The turntable motor 20 is an AC drive motor for rotating a turntable rotatably connected to a tray provided below the cooking chamber and supporting a container filled with food. . The turntable motor 20 performs a predetermined cooking function while the main switch 10 is turned on, so that the third relay switch 22 is turned on by the second relay switch 1.
If the switch is turned on together with 8, the commercial AC power supply AC is applied and the motor is rotated.

On the other hand, the high-voltage transformer 24 applies a commercial AC power supply AC from its primary side coil 24a and a high voltage corresponding to each winding ratio from a secondary side coil 24b as the main switch 10 is turned on. appear. In a booster circuit including a high-voltage capacitor HVC and a high-voltage diode HVD, a high voltage generated from the high-voltage transformer 24 is boosted and applied to the magnetron MGT.

[0010] According to the conventional AC microwave oven power supply driving device constructed as described above, when the user opens the cooking chamber door and turns off the door detection switch, the first relay switch 14 is inverted. Is turned on, the door lamp 12 is turned on by the commercial AC power supply.
Lights when AC is applied. At this time, since the main switch 10 maintains the switch-off state, the high-voltage transformer 24 becomes difficult to apply an AC voltage from the commercial AC power supply AC, and the operation of generating a high voltage is prohibited.

On the other hand, when the cooking chamber door is closed and the main switch 10 is turned on, the high-voltage transformer 24 is turned off.
The preparation for execution of the cooking function is completed by applying an AC voltage from the commercial AC power supply AC.

In this state, when the user performs a predetermined cooking function, the magnetron MGT starts driving to generate microwaves, and the second relay switch 18 and the third relay switch 22 are operated in conjunction with the switches. The fan motor 16 and the turntable motor 20 are driven to rotate while being turned on.

Therefore, the food rotating on the turntable in the cooking chamber is heated / cooked by the microwave generated from the magnetron MGT.

On the other hand, such a conventional AC microwave oven power supply driving device is designed to be driven using only the commercial AC power supply AC, so that it is difficult to supply AC power to the outdoors, vehicles, ships, and so on. There arises a problem that it cannot be used on an aircraft or the like.

In order to solve such a problem, recently, an inverter for converting a DC voltage from a DC power source such as a vehicle power source or a portable power source such as a vehicle into an AC voltage has been developed. Inverters) have been developed and are being used.

A door lamp and a fan motor used in the DC microwave oven are driven by applying a DC voltage as it is, while a turntable motor for rotating a turntable in a cooking chamber is driven by applying a DC voltage as it is. Adopts a DC motor.

However, when the turntable motor for rotating the turntable in the DC microwave oven is used as an expensive DC motor, the overall manufacturing cost is increased, and as a result, additional consumers are required. The problem is that the cost burden is increased.

[0018]

SUMMARY OF THE INVENTION Accordingly, the present invention has been devised to solve the above-mentioned problems.
The aim is to apply a DC microwave oven turntable motor as an inexpensive AC motor, convert DC voltage to AC voltage, and rotate the turntable motor to reduce the overall manufacturing cost burden. An object of the present invention is to provide a turntable motor drive circuit of a DC microwave oven that can be driven.

Another object of the present invention is to provide a turntable for a DC microwave oven capable of easily generating a DC voltage required for other drive circuit terminals through a drive circuit for driving a turntable motor as an AC motor. An object of the present invention is to provide a motor drive circuit.

[0020]

According to the present invention, there is provided a turntable motor drive circuit for a DC microwave oven according to the present invention, which converts a DC voltage into an AC voltage by a start input of a cooking function. Control means for generating a drive control pulse, inverter means for applying a drive control pulse from the control means to convert a DC voltage of a DC power supply into an AC voltage, and converting the AC voltage converted by the inverter means for motor drive. A turntable motor drive circuit for a DC microwave oven, comprising: a transformer means for transforming to a required voltage; and a turntable motor comprising an AC motor to which an AC voltage transformed by the transformer means is applied and rotated. I will provide a.

Preferably, the drive control pulse of the control means comprises a plurality of pulse signals whose respective pulse periods are alternately inverted, and the inverter means receives the plurality of drive control pulses and alternately turns on / off. And a plurality of driven power transistors.

More preferably, in a preferred embodiment of the present invention, a rectifier for rectifying the AC voltage induced by the transformer, and a voltage for adjusting the DC voltage rectified by the rectifier to a required voltage and outputting the adjusted voltage. A regulator is further included, and the regulated voltage from the voltage regulator is supplied to other operation circuit terminals as operation power.

According to the present invention, the turntable motor for rotating the turntable on which the food is settled in the DC microwave oven is applied as an inexpensive AC motor. Not only can the production cost be reduced, but also the burden of purchasing costs on the consumer can be reduced.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention constructed as described above will be described in detail with reference to the accompanying drawings.

FIG. 2 is a circuit diagram showing a configuration of a turntable driving circuit of a DC microwave oven according to a preferred embodiment of the present invention. In the circuit of the present invention shown in FIG. A DC power source 30 for generating a DC voltage, and a door lamp 32 and a fan motor 36 that are turned on and driven to rotate by applying a DC voltage from the DC power source 30 by switching operations of a first relay switch 34 and a second relay switch 38. Be composed.

Also, in the circuit of the present invention, a door detection switch DSW which performs a switching operation by detecting an opening / closing operation of a microwave oven door, and a driving circuit which generates an alternating driving pulse every predetermined period by the switching operation of the door detection switch DSW. 46, first and second field-effect transistors 48 and 50 that are alternately turned on / off by applying alternate drive pulses from the drive circuit 46 are configured.

In the same figure, the first and second
Due to the alternating on / off operation of the field effect transistors 48 and 50, a DC voltage from the battery power supply 30 is applied through the primary coil 52a, and is transformed into a high AC voltage through the secondary coil 52b. The high-voltage transformer 52 includes first and second interlock switches SW1 and SW2 that are switched according to the open / close state of the cooking chamber door and permit or block the application of the DC voltage to the high-voltage transformer 52.

The secondary coil 52b of the high voltage transformer 52 has a high voltage capacitor HVC and a high voltage diode HVD for boosting a high AC voltage, and a surge blocking capacitor for blocking a surge voltage induced in the high voltage transformer 52.
And a magnetron MGT which is driven by applying an AC voltage boosted by the high voltage capacitor HVC and the high voltage diode HVD to generate a microwave.

However, the characteristic features of the preferred embodiment of the present invention include a microcomputer 54, first and second power transistors 56 and 58 as push-pull circuits, a transformer 60, and a turntable motor 62 as an AC motor. Is configured. Further, in the present invention, a bridge diode 64 and a voltage regulator 66 for rectifying and converting the AC voltage from the transformer 60 into a constant voltage are provided.

On the other hand, the microcomputer 54 performs control for adjusting the cooking state of the food according to the button input of the function button operated by the user. The microcomputer 54 alternately generates first and second drive control pulses whose mutual pulse periods are inverted at regular intervals through the first and second control output terminals E1 and E2, and the first and second power transistors. 56 and 58 are alternately turned on / off.

The first and second power transistors 56 and 58 receive first and second drive control pulses from the first and second control output terminals E1 and E2 of the microcomputer 54 through their respective base ends. They are alternately turned on / off.

The transformer 60 is connected to the first and second transformers.
By alternately turning on / off the power transistors 56 and 58, a DC voltage of, for example, 12 V from the DC power supply 30 is applied through the primary coil 60a, and the turntable motor 62 is driven through the secondary coil 60b. The voltage is changed to an AC voltage of 21 V necessary for rotational driving.

Then, a turntable motor 62 applied as the AC motor is driven by applying an AC voltage of 21 V transformed by the transformer 60 to rotate a turntable (not shown) in the cooking chamber.

Thereafter, the bridge diode 64 rectifies the AC voltage from the transformer 60 and outputs the rectified voltage. The voltage regulator 66 converts the rectified DC voltage to a constant voltage of 15 V to detect the door voltage. This is applied to one end of the switch DSW.

Accordingly, the drive circuit 46 can be driven by applying a 15 V DC voltage from the voltage regulator 66 through its power supply terminal Vcc according to the ON state of the door switch DSW.

Next, the operation of the DC microwave oven according to the present invention performed on the turntable motor driving circuit according to the present invention will be described in detail with reference to FIGS.

First, when the cooking chamber door (not shown) of the DC microwave oven is opened, the door detection switch DSW detects this and is turned off, whereby the first relay switch 34 is turned on and the DC power supply is turned on. The DC voltage from 30 is applied to the door lamp 32 to light it.

The DC voltage from the DC power supply 30 is applied to the primary side coil 52a of the high voltage transformer 52 while the first and second interlock switches SW1 and SW2 are turned on by the open state of the cooking chamber door. Make things go away.

In this state, the turntable in the cooking chamber
If the food is settled on the door (not shown) and the door is closed, the door detection switch DSW detects this and turns on the first relay switch 34 to turn off the door lamp 32 when it is turned on. .

On the other hand, when the microcomputer 54 recognizes that a predetermined function button (not shown) for instructing the start of cooking is operated while recognizing the switch-on operation of the door detection switch DSW, the microcomputer 54 informs the user of the operation. A first in which the pulse period is alternately inverted through the first and second control output terminals E1 and E2.
And a second drive control pulse is generated (see FIG. 3).

The first and second power transistors 56 and 58 are applied with the first and second drive control pulses through their respective base ends, and are turned on / off alternately at regular intervals.

Thus, the transformer 60 applies a 12V DC voltage from the DC power supply 30 to the primary coil 60a and induces an AC voltage transformed to 21V through the secondary coil 60b (see FIG. 6). 3).

As a result, the turntable motor 62 adopted as the AC motor is applied with the AC voltage of 21 V from the transformer 60 and is driven to rotate to rotate the turntable on which the food is settled.

At this time, the bridge diode 64 has a voltage of 21 V induced in the secondary coil 60b of the transformer 60.
Rectifies the AC voltage of the
6 regulates the rectified DC voltage to a constant voltage of 15V.

Accordingly, the drive circuit 46 is driven by applying a 15 V DC voltage from the voltage regulator 66 through the door sensing switch DSW through the power supply terminal Vcc and driving the high pulse through the first and second output terminals O1 and O2. Generates the first and second drive pulses that are alternately inverted.

Accordingly, the first and second field effect transistors 48 and 50 apply the first and second driving pulses generated from the driving circuit 46 through their base ends, respectively, and alternately turn on / off the high and low voltages. An AC voltage is induced in the primary coil 52a of the transformer 52.

On the other hand, the high-voltage transformer 52 generates a high-voltage AC voltage through its secondary coil 52b based on the winding ratio with the primary coil 52a. The voltage is extinguished, and a high-voltage AC voltage boosted by a high-voltage capacitor HVC and a high-voltage diode HVD is applied and driven to generate a microwave.

As a result, the microwave generated from the magnetron MGT heats / cooks the food on the turntable rotated by the turntable motor 62 employed as the AC motor.

[0049]

As described above, according to the present invention, a turntable motor for rotating a turntable in a cooking chamber in a DC microwave oven used by converting a DC voltage to an AC voltage is used as an inexpensive AC motor. By doing so, it is possible not only to reduce the overall manufacturing cost, but also to reduce the cost burden on the consumer.

The present invention is not limited to the specific preferred embodiments described above, but may be variously modified by anyone having ordinary knowledge in the technical field to which the present invention pertains without departing from the spirit of the present invention. Such modifications are, of course, possible within the scope of the claims set forth.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram showing a circuit configuration of a conventional general AC microwave oven power supply driving device.

FIG. 2 is a circuit diagram showing a configuration of a turntable motor drive circuit of a DC microwave oven according to a preferred embodiment of the present invention.

FIG. 3 is a waveform diagram illustrating an operation of converting a DC voltage into an AC voltage for driving a turntable motor according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 30 DC power supply 32 Door lamp 34, 38 First and second relay switches 36 Fan motor 46 Drive circuit 48, 50 First and second field effect transistors 52 High voltage transformers 52a, 52b Primary and secondary coils 54 Microcomputer 56, 58 First and second power transistors 60 Transformers 60a, 60b Primary and secondary coils 62 Turntable motors 64 Bridge diodes 66 Voltage regulators

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) // F24C 7/02 551 F24C 7/02 551P (72) Inventor Kang Gwang-sin Incheon-gu, Seoul (No address) Sungjing 3rd APT 304-803 (72) Inventor Sung Han-shun 473-6 Fang-dong 2-dong, Seocho-gu, Seoul, Republic of Korea

Claims (4)

[Claims] 1. A control means for generating a drive control pulse for converting a DC voltage to an AC voltage according to a start input of a cooking function, and a drive control pulse from the control means is applied to reduce a DC voltage of a DC power supply. Inverter means for converting the AC voltage into an AC voltage; transformer means for transforming the AC voltage converted by the inverter means into a voltage required for driving the motor; and AC voltage formed by an AC motor and transformed by the transformer means. A turntable motor drive circuit for a DC microwave oven, comprising a turntable motor that is driven to rotate. 2. The drive control pulse of the control means comprises a plurality of pulse signals whose respective pulse periods are alternately inverted, and the inverter means applies the plurality of drive control pulses and turns on / off alternately. 2. The circuit according to claim 1, further comprising a plurality of power transistors. 3. A rectifier for rectifying an AC voltage induced by the transformer, and a voltage regulator for adjusting a DC voltage rectified by the rectifier to a required voltage and outputting the regulated voltage. The drive circuit for a turntable motor of a DC microwave oven according to claim 1, wherein: 4. The turntable motor driving circuit for a DC microwave oven according to claim 3, wherein the regulated voltage from the voltage regulator is supplied to other operation circuit terminals as operation power. .