JP2974864B2 - Magnetron drive transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron driving transformer for protecting a magnetron in an inverter type high frequency heating device such as a microwave oven.

[0002]

2. Description of the Related Art An outline of a conventional high-frequency heating device for driving a magnetron with an inverter power supply will be described with reference to FIG.

[0005] A commercial power supply 1 is rectified by a rectifying bridge 2 and smoothed by a choke coil 3 and a smoothing capacitor 4 to form a rectifying and smoothing circuit 5.

A step-up transformer 6 (transformer) for driving a magnetron is connected to the rectifying / smoothing circuit 5, and a resonance capacitor 7 is connected to the transformer 6 in series or in parallel (in FIG. 12).
Are connected to form a resonance circuit, and a semiconductor switching element 8 is connected to the resonance circuit to form an inverter circuit 9.

[0005] A high voltage diode 11 and a high voltage capacitor 12 are connected to the secondary circuit of the transformer 6 constituting the inverter circuit 9 to form a voltage doubler circuit, which serves as a magnetron driving circuit, and further comprises a magnetron 13. It is connected.

[0006] The cathode of the magnetron 13 is connected to the secondary winding 14 of the transformer 6, and the cathode voltage of the magnetron 13 is connected to the control circuit 15 via the capacitor 12 and the secondary winding 14. By sending a signal to the drive circuit 16 by the circuit 15, optimal control by feedback is performed. That is, the control circuit 15
In response to a magnetron output setting signal from a main controller 17 for controlling the entire system, a drive circuit 16 is provided to control the output based on the detection results of input / output voltages and currents.
The driving pulse width and the driving timing of the semiconductor switching element 8 are adjusted through the operation.

Here, the resistor 18 is for detecting the magnetron anode current, and the voltage across the resistor is input to the control circuit 15 as a current value.

The output of the control winding 19 is input to the control circuit 15 for synchronization and output voltage detection.

An input current of the high-frequency heating device is detected from a current consumption detection circuit 21 and input to a control circuit 15.

The above is the outline of the high-frequency heating device for driving the magnetron with the inverter power supply.

In FIG. 12, reference numeral 22 denotes a primary winding of the transformer 6, and reference numeral 23 denotes a heat winding for heating the magnetron 13.

[0012]

In the conventional method, when an abnormal oscillation of the magnetron 13 occurs, the phenomenon is detected, the information is input to the control circuit 15, and the adjustment is performed according to the information. Therefore, there is no protection function for stopping the progress of the characteristic deterioration of the magnetron 13.

Therefore, once the abnormal oscillation occurs, the self-heating becomes excessive and the anode temperature of the magnetron 13 rises rapidly, so that the magnetron 13 itself is destroyed.

In FIG. 12, the control winding 19 is provided for detecting the output voltage. However, since the above-described abnormality occurs rapidly, the control winding 19 disposed on the primary side is provided.
However, the detection was not enough, and the detection was not enough in practical use. In consideration of this, the detection winding for mounting the protection function must be installed on the high voltage side of the magnetron driving transformer 6. In addition, the structure must be inexpensive while ensuring the insulation safety.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a high-frequency heating apparatus having an inexpensive structure while preventing an increase in the temperature of an anode of a magnetron at the time of abnormal oscillation, improving durability, and ensuring insulation safety. With the goal.

[0016]

According to the first aspect of the present invention, as shown in FIGS. 1 to 3, a step-up power supply is supplied to a high-frequency heating magnetron 13, and a primary power is supplied to a conductive core 30. A winding 22 and a secondary winding 14 and a detector 25 for detecting the oscillation state of the magnetron 13 are provided, and the detector 25 is a driving transformer for differentially detecting a change in the magnetron cathode voltage. A winding is wound around the secondary side of the vessel 6, and a bobbin 39 for winding and fixing the detection body 25 is attached to the core 30.

The means for solving the problem according to the second aspect of the present invention is to supply a step-up power supply to the high-frequency heating magnetron 13 as shown in FIGS. A winding 14, a fixed band 38 for fixing the core 30 to the insulating case 36, and a detector 25 for detecting the oscillation state of the magnetron 13 are provided. The detection body 25 is formed from a conductive metal plate disposed on the secondary inner periphery of the core 30 with an insulator 51 interposed therebetween. Thus, by being connected to the outer periphery of the secondary side of the core 30 of the fixed band 38, a winding surrounding the secondary side of the core 30 is formed.

According to a third aspect of the present invention, as shown in FIG. 6, the detection body 25 is formed of a substantially U-shaped metal wire engaged around the secondary side of the core 30. 25
Is formed so as to be directly inserted and fixed into the connection hole 55 of the external mounting board 54.

According to a fourth aspect of the present invention, as shown in FIG. 7, the detector is wound around the secondary side of the driving transformer 6 so as to differentially detect the fluctuation of the magnetron cathode voltage. A guide groove 57 for winding a detection body is formed on the secondary side of the core 30 as a winding.

According to a fifth aspect of the present invention, as shown in FIGS. 8 and 9, the detector 25 is disposed on the secondary side of the driving transformer 6 so as to differentially detect the fluctuation of the magnetron cathode voltage. An insulating resin bobbin 40 for fixing the detecting body 25 to the secondary side of the core 30 is provided, and the detecting body 25 is formed by insert molding integrally with the insulating resin bobbin 40. is there.

According to a sixth aspect of the present invention, as shown in FIG. 10, a primary winding is wound around a primary side of a conductive core 30 and a secondary winding is wound around a secondary side of the core 30. The periphery of the secondary side of the core 30 is the printed circuit board 6
4, a detection body 25 for differentially detecting the fluctuation of the magnetron cathode voltage is formed as a metal foil wiring on the printed board 64.

According to a seventh aspect of the present invention, there is provided a magnetron driving transformer according to the first to sixth aspects.
The mounting position of the detector 25 on the core 30 is determined by the secondary winding 14
Is separated from the winding position.

[0023]

In the above-mentioned means for solving the above problems, the state of oscillation at the cathode of the magnetron 13 is differentially detected by the detector 25 arranged on the secondary side of the driving transformer 6, and when abnormal oscillation occurs, supply of step-up power is performed. To stop. Thereby, a quick response can be performed, and the durability thereof can be improved.

Further, in particular, in the first aspect, the bobbin 39
In claim 2, the fixing band 38, in claim 3, the connection hole 55 of the external mounting board 54, and in claim 4, the guide groove 57
According to the fifth aspect, the insulating resin bobbin 40 is integrally formed by insert molding, and the sixth aspect has a structure in which the detection position of the detection body 25 is determined by the printed circuit board 64, so that the output variation is suppressed. be able to.

According to the seventh aspect, the creepage distance is increased with respect to the secondary winding of the core, so that the insulating member is provided between the high-voltage portion on which the secondary winding is disposed and the detector. Can be secured sufficiently.

[0026]

【Example】

[First Embodiment] FIGS. 1 and 2 show a magnetron driving transformer (transformer) according to a first embodiment of the present invention, and FIG. 3 shows an example of a high-frequency heating apparatus (microwave oven) using the magnetron driving transformer. Are shown below. Note that members having the same functions as those in the conventional example of FIG. 12 are denoted by the same reference numerals.

(Configuration of High Frequency Heating Apparatus of First Embodiment) First, the outline of the high frequency heating apparatus of the present embodiment will be described.

As shown in FIG. 3, the high-frequency heating apparatus according to the present embodiment includes a magnetron 13 for high-frequency heating and a transformer 6 for driving the magnetron for supplying a boosting power to the magnetron 13.
An inverter circuit 9 for driving the transformer 6 for driving the magnetron; a rectifying and smoothing circuit 5 for rectifying and smoothing the commercial power supply 1 to supply DC power to the inverter circuit 9; A circuit 16, a control circuit 15 for controlling the drive circuit 16, and a main control device 17 for supplying a magnetron output setting signal to the control circuit 15 and controlling the operation of the entire system are provided.

The inverter circuit 9 is a general circuit composed of a connection composed of a switching element 8, a resonance capacitor 7, and the primary winding 22.

The switching element 8 includes a primary winding 22
And the resonance capacitor 7.

The resonance capacitor 7 is connected to the primary winding 22 of the driving transformer 6, and forms a resonance circuit together with the primary winding 22.

The rectifying / smoothing circuit 5 rectifies the commercial power supply 1 with the rectifying bridge 2 and smoothes it with the choke coil 3 and the smoothing capacitor 4.

The control circuit 15 includes a main controller 17
The switching element 8 is connected to the switching element 8 so that the magnetron 13 oscillates at the output given by the output setting signal in synchronization with a signal from the control winding 19 described later. Drive control is carried out via 16.

Further, the control circuit 15 is provided with a detector 2 to be described later.
When 5 detects an abnormal oscillation of the magnetron 13, it transmits a stop signal to the drive circuit 16.

That is, when the stop signal is not supplied, the control circuit 15 drives the switching element 8 with the supply of the magnetron output setting signal,
When the stop signal is supplied or when the magnetron output setting signal is interrupted, the driving of the switching element 8 is stopped.

The main control unit 17 receives a signal from an operation button of an operation unit of the high-frequency heating device, displays this information on a display panel, and when the magnetron 13 is driven, sends a magnetron output setting signal to the control circuit 15. Send

Here, 11 is a high-voltage diode, 12 is a high-voltage capacitor, and these are connected to form a voltage doubler circuit as a magnetron drive circuit.

Reference numeral 18 denotes a resistor for detecting a magnetron anode current, and the voltage across the resistor 18 is input to the control circuit 15 as a current value.

When the current value becomes larger than a predetermined value, the control circuit 15 stops driving the switching element 8. Since only the current value is detected from the resistor 18, abnormal oscillation of the magnetron cannot be detected.

Reference numeral 23 denotes a heat winding for heating the magnetron 13. The cathode of the magnetron 13 is connected to the heat winding 23, and the cathode voltage of the magnetron 13 is controlled by a signal from the control circuit 15.

Further, reference numeral 19 denotes a secondary-side control winding input to the control circuit 15 for synchronization and output voltage detection.

Reference numeral 21 denotes a consumed current detecting circuit which detects an input current of the high frequency heating device and inputs the detected current to the control circuit 15.

Reference numeral 26 denotes a detection winding output shaping circuit for shaping the output of a detection body 25 described later before reaching the control circuit 15. The detection winding output shaping circuit 26 and the control circuit 15
A circuit unit having a plurality of elements mounted on a substrate such as an IC is used.
A general microcomputer having an AM is used.

(Configuration of the Magnetron Driving Transformer of the First Embodiment) The magnetron driving transformer 6 of the present embodiment includes a primary winding 2 and a conductive core 30 as shown in FIGS.
2 and a secondary winding 14 and a detector 25 for detecting the oscillation state of the magnetron 13 are provided.

As shown in FIG. 1, the core 30 comprises a primary (low-voltage side) core 31 around which the primary winding 22 is wound, and a secondary (high-voltage side) core 32 around which the secondary winding 14 is wound.

As shown in FIG. 2, each of the iron cores 31 and 32 includes a winding portion 33 around which the windings 22 and 14 are wound, an arm portion 34 extending vertically from an end of the winding portion 33, A connecting portion 35 extending vertically from the portion 34 and connected in parallel with the winding portion 33;
2 are formed in a substantially rectangular shape as shown in FIG. Here, each part 31, 32 of the core 30
Is supported by an insulating case 36 made of an insulator using a conductive material such as iron. The two iron cores 31, 32
Are disposed on both sides of the insulating wall 37 of the insulating case 36 and are insulated from each other.

The core 30 is held by a fixing band 38 for fixing the core 30 to the insulating case 36. The fixing band 38 is formed of a metal rod bent from the primary outer peripheral portion to the secondary outer peripheral portion of the core 30.

A bobbin 39 around which the detection body 25 is wound and fixed is attached to the arm 34 of the secondary iron core 32 of the core 30.

As shown in FIG. 2, the bobbin 39 is made of, for example, an insulating epoxy resin. The bobbin 39 surrounds the entire periphery of the arm portion 34 of the secondary iron core 32 and has a body portion 41 around which the detection body 25 is wound in a coil shape. At the lower end of the body 41, a key-shaped projection 42 for fastening and fixing the detection body 25 is integrally formed. The mounting position of the bobbin 39 on the secondary iron core 32 is as follows:
The position is set so as to be separated from the secondary winding 14 so as to maintain the insulating property, and to be close enough that the electromagnetic influence from the primary winding 22 is not attenuated.

The primary winding 22 is wound around a winding portion 33 of a primary iron core 31 of the core 30.

The secondary winding 14 is wound around a winding portion 33 of a secondary iron core 32 of the core 30.

The detection body 25 is a winding wound around the bobbin 39. The detection body 25 is a bobbin 3
The reason why the coil is wound around the secondary side of the driving transformer 6 via 9 is to differentially detect the fluctuation of the cathode voltage of the magnetron 13.

The detector 25 is connected to the control circuit 15 via the detection winding output shaping circuit 26 as shown in FIG.

In FIG. 1, reference numeral 40 denotes each of the windings 22, 14;
An insulating resin bobbin for maintaining electrical insulation between the core and the core 30.

(Operation of High-frequency Heating Apparatus of First Embodiment) In the high-frequency heating apparatus having the above-described configuration, first, as shown in FIG. On / off control is performed by the element 8,
As a result, the resonance circuit including the capacitor 7 and the primary winding 22 resonates, and power is supplied to the magnetron 13 via the driving transformer 6.

At this time, the output of the detector 25 is input to the detection winding output shaping circuit 26.

Here, when the output of the detector 25 is normal, the control circuit 15 operates the drive circuit 16 normally.

However, when the magnetron 13 oscillates abnormally, the output of the detector 25 becomes abnormal. The control circuit 15 that has detected this abnormal state transmits a stop signal to the drive circuit 16.

At this time, the control circuit 15 stops the switching element drive signal to the drive circuit 16 for a certain period based on the stop signal, while the magnetron output setting signal from the main control device 17 is still supplied. Then, the oscillation of the magnetron 13 is stopped to prevent the magnetron 13 from being destroyed due to overheating due to abnormal oscillation.

By repeating the above operation every time abnormal oscillation occurs, automatic escape from the abnormal oscillation of the magnetron 13 can be realized, the magnetron 13 itself is prevented from being destroyed, and the operating life is extended.

Incidentally, as shown in FIGS. 1 and 2, the detection winding 25 of the magnetron driving transformer 6 can be wound and fixed by the bobbin 39 at the time of assembling, so that the transformer can be easily assembled.

Since the bobbin 39 has a structure in which the detection position of the detection body 25 is determined, it is possible to suppress variations in the output.

Furthermore, since the bobbin 39 is insulative, sufficient insulation between the high-voltage portion on which the secondary winding 14 is disposed and the detector 25 can be ensured.

[Second Embodiment] A magnetron driving transformer 6 according to a second embodiment of the present invention, as shown in FIGS. It is used as part of. That is, the detection body 25 of the present embodiment is made of a side-view ladle-shaped metal plate disposed on a part of the outer peripheral wall of the arm portion 34 of the secondary iron core 32 with the insulator 51 interposed therebetween. The core 30 is connected to the outer peripheral portion on the secondary side.

The fixed band 38 is, as shown in FIGS.
It is a metal rod bent in a substantially U-shape, and both ends of the metal rod have elasticity toward the inside, and both iron cores 3 of the core 30 are formed.
1, 32 are pinched inside. Therefore, each iron core 31, 3
An engagement hole 52 that engages with the fixing band 38 is formed on the surface of the second member 2. At a position corresponding to the engagement hole 52 of the fixing band 38, a bent portion 53 bent inwardly to be engaged with the engagement hole 52 is formed.

The connection between the detection body 25 and the fixed band 38 may be made simply by contact or by soldering. In the case where the detection body 25 is merely brought into contact with the fixed band 38, it is desirable that the detection body 25 has appropriate elasticity for urging in the direction of the fixed band 38.

Here, the insulator 51 is made of an insulating case 3
It is desirable to form them in advance integrally with the same.

Further, as in the first embodiment, the mounting position of the detector 25 is spaced apart from the secondary winding 14 so as to maintain the insulating property, and the electromagnetic influence from the primary winding 22 is not attenuated. The position is close to.

Further, the bobbin for the detection object provided in the first embodiment is omitted in this embodiment.

The other structure is the same as that of the first embodiment.

According to the above configuration, the arm 3 of the core 30
There is no need to wind a winding around 4, and the assembling work becomes extremely simple.

Further, since the fixing band 38 is fixed at the position where the engaging holes 52 of the iron cores 31 and 32 are formed, the mounting position of the detector 25 connected to the fixing band 38 is also fixed. Mounting position, and thus each iron core 3
The positions of the first and second engagement holes 52 are restricted. That is, since the structure is such that the detection position of the detection body 25 is determined, it is possible to suppress variations in the output.

[Third Embodiment] A magnetron driving transformer according to a third embodiment of the present invention is, as shown in FIG.
Is wound around the insulator 51 such as a rubber, the U-shaped detection body 25 is inserted into the insulation 51, and the end of the detection body 25 is further inserted into the connection hole 55 of the external printed circuit board 54. Insert connection.

Here, a general copper foil pattern 56 connected to the detector 25 is formed on the printed circuit board 54. When the copper foil pattern 56 and the detection body 25 are considered together, a detection coil surrounding the entire periphery of the arm portion 34 of the secondary iron core 32 is formed.

In this embodiment, since the detector 25 is formed in a U-shape, the secondary core 3
Since it is only necessary to insert the detection body 25 from above the second arm part 34 and insert and connect the end of the detection body 25 to the connection hole 55 of the printed circuit board 54, assembly can be performed easily.

Further, since the mounting position of the detection body 25 is restricted by the formation position of the connection hole 55 of the printed circuit board 54, the detection position by the detection body 25 can be determined.
Variations in the output can be suppressed.

Fourth Embodiment A magnetron driving transformer according to a fourth embodiment of the present invention uses the same winding as that of the first embodiment as a detector as shown in FIG. A guide groove 57 for winding the detection body is formed in the portion 34.

With such a configuration, the mounting position of the detection body can be restricted by the guide groove 57 of the arm portion 34 of the secondary iron core 32, and the detection position by the detection body can be determined, which is extremely simple. With a simple structure, it is possible to suppress variations in the output.

Fifth Embodiment A magnetron driving transformer according to a fifth embodiment of the present invention is, as shown in FIGS. 8 and 9, insulated at the portion where the secondary core 32 of the insulating resin bobbin 40 of the transformer 6 is inserted. The detection body 25 formed into a U-shape is integrally formed on the wall 61 during resin molding, and an external lead 62 is connected to an end protruding from the surface. When the external lead 62 and the detection body 25 are considered together, a detection coil surrounding the entire periphery of the arm portion 34 of the secondary iron core 32 is formed.

With this configuration, the mounting position of the detector 25 can be fixed to the insulating resin bobbin 40, and the detection position by the detector 25 can be determined.
With an extremely simple structure, it is possible to suppress variations in the output.

Further, the detecting body 25 is connected to the insulating resin bobbin 40.
Since it is integrated into the unit, handling during assembly becomes convenient.

[Sixth Embodiment] A magnetron driving transformer according to a sixth embodiment of the present invention, as shown in FIG.
A printed circuit board 64 is attached to the arm portion 34 so as to surround the entire periphery thereof. The printed circuit board 64 is formed by forming a metal foil wiring 25 on an insulating plate based on an insulating material, and has a central hole 66 formed at the center thereof to penetrate the arm 34 of the secondary core 32. ing. The metal foil wiring 25 is formed so as to surround substantially the entire periphery of the center hole 66. Thereby, the metal foil wiring 25 becomes
It functions as a detection body (detection coil) surrounding the entire periphery of the arm portion 34 of the secondary iron core 32.

In this embodiment, since the detector 25 is integrated with the printed circuit board 64, the handling at the time of assembly becomes convenient.

Note that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention.

For example, in the first embodiment, the high-frequency heating device using the magnetron driving transformer has been described with reference to FIG. 3, but as shown in FIG. The main control circuit 17 may transmit the stop signal to the main control circuit 17 when the magnetron abnormally oscillates.

[0086]

As is clear from the above description, according to the present invention, since the detector is provided on the secondary side of the core, the oscillation state at the cathode of the magnetron can be detected differentially. Then, when an abnormal oscillation occurs, this can be quickly found, a quick response can be taken, and the durability of the magnetron can be greatly improved.

Further, in particular, the first aspect is a bobbin, the second aspect is a fixed band, the third aspect is a connection hole of an external mounting board, the fourth aspect is a guide groove, and the fifth aspect is an integral part. 7. An insulating resin bobbin formed by insert molding.
Since the printed circuit board has a structure in which the detection positions of the detection objects are determined on the printed circuit board, variations in the output can be suppressed.

Further, the time required for positioning the detection body can be reduced, and the assembling work can be simplified.

According to the seventh aspect, the creepage distance is increased with respect to the secondary winding of the core, whereby sufficient insulation between the high-voltage portion on which the secondary winding is disposed and the detector is ensured. There is an excellent effect that it can be done.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a driving transformer according to a first embodiment of the present invention.

FIG. 2 is a bobbin of the driving transformer according to the first embodiment of the present invention;
Perspective view showing core and detector

FIG. 3 is a control block diagram of the high-frequency heating device according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing a driving transformer according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a core, a fixed band, and a detection body of a driving transformer according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing a core, a detector, and a mounting board of a driving transformer according to a third embodiment of the present invention.

FIG. 7 is a perspective view showing a core and guide grooves of a driving transformer according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view showing a driving transformer according to a fifth embodiment of the present invention.

FIG. 9 is a sectional view showing a core, an insulating resin bobbin, and a detection body of a driving transformer according to a fifth embodiment of the present invention.

FIG. 10 shows a driving transformer core according to a sixth embodiment of the present invention;
Perspective view showing a detection body and a mounting board

FIG. 11 is a control block diagram of a high-frequency heating device showing another example of the present invention.

FIG. 12 is a control block diagram of a conventional high-frequency heating device.

[Explanation of symbols]

 6 Drive Transformer 13 Magnetron 14 Secondary Winding 22 Primary Winding 25 Detector 30 Conductive Core 36 Insulating Case 38 Fixed Band 39 Bobbin 40 Insulating Resin Bobbin 51 Insulator 54 Mounting Board 55 Connection Hole 57 Guide Groove 64 Printed Circuit Board

Claims (7)

(57) [Claims] An apparatus for supplying a step-up power supply to a high-frequency heating magnetron, wherein a conductive core is provided with a primary winding and a secondary winding, and a detector for detecting an oscillation state of the magnetron, The detector is a winding wound on a secondary side so as to differentially detect the fluctuation of the magnetron cathode voltage, and a bobbin for winding and fixing the detector is attached to the core. Magnetron driving transformer. 2. A high-frequency heating magnetron for supplying a step-up power supply, comprising: a conductive core; a primary winding and a secondary winding; a fixed band for fixing the core to an insulating case; A detector for detecting an oscillation state is provided, wherein the fixed band is a metal rod bent and arranged from a primary outer peripheral portion to a secondary outer peripheral portion of the core; A winding surrounding the secondary side of the core by being made of a conductive metal plate disposed on the inner side of the secondary side via an insulator and being connected to the outer peripheral side of the secondary side of the core of the fixed band. A transformer for driving a magnetron, wherein a transformer is formed. 3. A high-frequency heating magnetron for supplying step-up power to a magnetron, wherein a conductive core is provided with a primary winding and a secondary winding, and a detector for detecting an oscillation state of the magnetron, The detection body is formed of a substantially U-shaped metal wire engaged around the secondary side of the core, and the tip of the detection body is formed so as to be directly inserted and fixed into a connection hole of an external mounting board. A transformer for driving a magnetron. 4. A high-frequency heating magnetron for supplying a step-up power supply, wherein a conductive core is provided with a primary winding and a secondary winding, and a detector for detecting an oscillation state of the magnetron, The detector is a winding wound on the secondary side to differentially detect the fluctuation of the magnetron cathode voltage, and a guide groove for winding the detector is formed on the secondary side of the core. A transformer for driving a magnetron, characterized in that: 5. A high-frequency heating magnetron for supplying step-up power to a magnetron, wherein a conductive core is provided with a primary winding and a secondary winding, and a detector for detecting an oscillation state of the magnetron, The detector is a metal wire disposed on the secondary side so as to differentially detect the fluctuation of the magnetron cathode voltage, and an insulating resin bobbin for fixing the detector on the secondary side of the core is provided. A magnetron driving transformer, wherein the detection body is integrally insert-molded with an insulating resin bobbin. 6. A high-frequency heating magnetron for supplying a step-up power supply, wherein a primary winding is wound around a primary side of a conductive core, and a secondary winding is wound around a secondary side of the core. Is surrounded by a printed circuit board, and a detector for differentially detecting the fluctuation of the magnetron cathode voltage is formed as a metal foil wiring on the printed circuit board. 7. The magnetron driving transformer according to claim 1, wherein a mounting position of the core for the detection body is separated from a winding position of the secondary winding.