JP2541723Y2 - Inverter power supply for high frequency heating device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter power supply for a high-frequency heating device, and more particularly to a relationship between a printed circuit board and a high-voltage transformer.

[0002]

2. Description of the Related Art Microwave ovens using a so-called inverter type power supply, which converts DC obtained by rectifying a commercial AC power supply into high-frequency AC by a switching element, have been commercialized. According to this method, it is possible to reduce the size and weight of the high-voltage transformer that supplies power to the magnetron, and it is also possible to change the high-frequency output steplessly by controlling the on / off period of the switching element. is there.

In the high-voltage transformer used for the inverter power supply, since a high voltage of about 4 KV is generated in the high-voltage secondary winding, it is necessary to ground the magnetic core to prevent the high voltage from being induced in the magnetic core. General. As an example, there is known one in which a magnetic core is brought into contact with a jumper wire of a printed circuit board (Japanese Utility Model Laid-Open No. 2-95195).

[0004]

As in the prior art described above, the magnetic core is connected to the ground by simply contacting the magnetic core with the jumper wire on the printed circuit board, and the magnetic core is mounted close to the printed circuit board. In this case, the problem of leakage of high-voltage current between the various components arranged on the printed circuit board and the magnetic core becomes apparent due to the uncertainty of the ground connection due to contact, and the structural design and printing of the transformer There is a problem that the difficulty in designing the pattern layout of the substrate increases.

[0005]

In view of the above-mentioned problems, in the present invention, a core earth member made of a conductive material having a spring property is provided between a magnetic core of a high-voltage transformer and a bobbin for winding. This core grounding member is soldered to the ground wiring pattern of the printed circuit board while maintaining a necessary distance between the magnetic core and the printed circuit board.

[0006]

According to the above construction, the magnetic core is securely connected to the ground at a required distance on the printed circuit board.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of a high-voltage transformer, and FIG. 2 is a left side view. In these figures, 1a and 1b are U-shaped magnetic cores, 2 is a bobbin, 3 is a primary input winding, 4 is a secondary high voltage winding, and 5 is the U-shaped magnetic cores 1a and 1b as shown in FIG. Holding metal fittings for assembling and holding, 6 is a printed circuit board, 7 is a core earthing metal fitting which is mounted between the magnetic core 1a and the bobbin 2 and connects the potential of the core to an earth circuit of the printed circuit board 6, and 8 is the earth of the printed circuit board. This is a ground lead wire for guiding the pattern to the ground of the housing.
FIG. 3 shows the appearance of the core grounding metal.

The magnetic cores 1a and 1b each have a U-shape, penetrate the hollow portion of the bobbin 2 from both ends, and are held by wire-shaped core holding members 5 from both ends. The core holding member 5 includes the magnetic cores 1a and 1b.
Have the same potential. Core earth fitting 7
Is mounted between the magnetic core 1a and the bobbin 2 and reaches the ground pattern of the printed circuit board 6 through the metal fitting supporting portion 10 opened on the bobbin 2 and is soldered. Since the core grounding member 7 has a spring property, electrical contact with the magnetic core 1 is reliably performed. The ground lead 8 connects the ground pattern of the printed circuit board 6 and the housing ground of the high-frequency heating device. As a result, the magnetic cores 1a and 1b can be mounted on the printed circuit board 6 at a required distance from the printed circuit board and at a position where the free design of the printed circuit board is not hindered. Is connected to the housing ground through the connecting lead wire 8.

[0010]

According to the present invention, the magnetic core can be reliably connected to the ground. Further, since it is not necessary to bring the magnetic core close to the printed circuit board, the degree of freedom in the structural design of the transformer and the pattern layout design of the printed circuit board is increased, and the cost of the inverter can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of a high-voltage transformer according to an embodiment of the present invention.

FIG. 2 is a left side view of the same.

FIG. 3 is an outline view of a core grounding member.

[Explanation of symbols]

 1a, 1b Magnetic core 2 Bobbin 6 Core grounding

Claims (1)

(57) [Scope of request for utility model registration] 1. A magnetic core, a winding bobbin, an input primary winding,
In an inverter power supply in which a high-voltage transformer having a high-voltage secondary winding is mounted on a printed circuit board, the magnetic core (1)
a) is mounted on a printed circuit board (6) at a required distance, and the core grounding member (7) made of a conductive material having a spring property is provided between the magnetic core (1a) and the winding bobbin (2). An inverter power supply for a high-frequency heating device, wherein one end is sandwiched and connected, and the other end is soldered to an earth pattern of the printed circuit board.