JPS6319791A - Electric source for magnetron - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a power supply device for high-frequency driving of a magnetron used in a microwave oven.

BACKGROUND OF THE INVENTION The parts of a conventional magnetron power supply device other than the control circuit are, as shown in FIG. The fixed power transistor 47 and current transformer 48 are mounted and wired on a printed circuit board 49, and the chassis 61 has the high frequency transformer 5o fixed thereon.
The printed circuit board 49 was fixed to. Specifically, the rectifier bridge 42 is screwed to the heatsink 41, this heatsink 41 is screwed to the printed circuit board 49, the legs of the rectifier bridge 420 are soldered to the printed circuit board 49, and the power transistor 47 is connected to the heatsink 46. The heatsink 46 was screwed to the printed circuit board 49, the terminals of the power transistor 47 were wired in the air with lead wires, and all other components were soldered to the printed circuit board 49.

Problems to be Solved by the Invention However, this conventional magnetron power supply device does not have a heatsink 4.
1.46 is required, there are restrictions on placement due to consideration of wind flow for heat dissipation, the dimensions are large because each is a finished part, and the high frequency transformer and other parts are For reasons such as the fact that magnetrons can only be fixed on the same plane, their dimensions are large and the degree of freedom in layout design is reduced, resulting in a problem in which the advantage of high-frequency drive of magnetrons, which is miniaturization, is lost.

Means for Solving the Problems In order to solve the above problems, the present invention consists of a rectifying bridge, a choke coil, a smoothing capacitor, a resonant capacitor, a power switching element, and a current transformer for detecting input current. This is a composite part that is wired on one heatsink and molded with synthetic resin, and this composite part and a high-frequency transformer are fixed and integrated.

Operation With the above configuration, the rectifier bridge, smoothing capacitor, choke coil, resonance capacitor, and power switching element are each mounted on the heatsink as bare elements, so a compact composite component can be constructed, and the composite component and high-frequency transformer can be combined. The three parts of the control circuit have a great degree of freedom in terms of size and arrangement, and it is possible to fixedly integrate the composite part and the high-frequency transformer.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4. .

As shown in FIG. 2, the circuit configuration of this embodiment is to rectify the power supply voltage of a commercial power supply 1 with a rectifier bridge 3,
The current is smoothed by a smoothing capacitor 5 and converted into direct current (pulsating current in this embodiment), and then switched by a flywheel built-in power transistor (power switching element) 7 connected in series to a high frequency transformer 8 and a resonance capacitor 6. Then, the voltage is converted to a high frequency, boosted to a high voltage by a high frequency transformer 8, and applied to the magnetron 9, and the heater voltage of the magnetron 9 is also supplied from the tertiary winding of the high frequency transformer 8. In addition, control is performed by detecting the input current with current transformer 2 and transmitting it to control circuit 1.
Feedback control is performed at 0. In the above circuit configuration, as shown in FIG. 3, the power transistor 7 is fixed on the heat sink 12 with the collector conductive to the heat sink 12, and the heat sink 12 is wire-bonded to the insulated and fixed terminals 25 and 26 to perform rectification. The bridge 3 is insulated and fixed to the heat sink 12,
The smoothing capacitor 5 and the resonance capacitor 6 are both insulated and fixed to the heatsink 12, the terminals 23 and 24 are provided, the terminal 24 is electrically connected to the heatsink 12, and the choke coil 4 is connected to the heatsink 12. Insulated and fixed with current transformer 2
is insulated and fixed to the heatsink 12, provided with terminals 21, 27, and 28, and connected between each element with a lead wire to form a circuit.
An outer frame 13 made of T is adhered to the heat sink 12, and the cavity 14 is molded and hardened with epoxy resin 16 to form a composite component 11 as shown in FIG. The heat sink 12 is a fin 12
&have. As shown in Figure 1, the high frequency transformer 8
A metal fitting 8C for tightening the core 8& is fixed by a radiator 12 of the composite component 11, and a high frequency transformer 8 is placed on the molded surface of the composite component 11, thereby integrating the composite component 11 and the high frequency transformer 8. 8b is a coil. Composite parts 1
All the components of 1 are in chip form except for the current transformer 2 and choke coil 4, so it is possible to increase the degree of integration, and the rectifier bridge 3, power transistor 7, smoothing capacitor 6, and resonance capacitor 6 can be Conventionally, each item was molded, but now only one molding process is required, reducing the number of manufacturing steps. In addition, since all the heat radiation from each component is performed by the heat radiator 12, it is possible to arrange the components freely without making the flow of air to each component a problem, so that the smallest size can be realized. Furthermore, composite parts 11
By integrating the high-frequency transformer 8 and the microwave oven, the space factor is greatly improved, and since the control circuit 1o and the control circuit 1o are apparently two parts, there is a high degree of freedom in placement in the microwave oven machine room, and the number of assembly steps is reduced. It can be reduced to a large extent.゛Effects of the Invention As described above, according to the present invention, the magnetron power supply device can be significantly downsized, and the number of man-hours for manufacturing the power supply can also be greatly reduced, resulting in very significant effects.

[Brief explanation of drawings]

FIG. 1a is a plan view of essential parts of a magneto Cl power supply device showing an embodiment of the present invention, FIG. 1 is a side view of the same, FIG. 1C is a front view of the same, and FIG. 2 is a same power supply device. 3 is a plan view of the composite component of the same power supply device in a state before resin molding, FIG. 4 is a perspective view of the same composite component after resin molding, and FIG. 6 is a conventional power supply device. FIG. 3... Rectifier bridge, 4... Choke coil, 5... Smoothing capacitor, 6...
・Resonance capacitor, 7...Power transistor, 8...High frequency transformer, 8C...
Metal fittings, 9... Magnetron, 11...
Composite parts, 12... Heat sink, 15...
Epoxy resin. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure m) (b> (C) Second 3rd section Figure 4

Claims (2)

[Claims] (1) An inverter power supply is constructed from a control circuit of a rectifier bridge, a power switching element, a high frequency transformer, and a power switching element, and includes a rectifier bridge, a choke coil, a smoothing capacitor, a resonance capacitor, a power switching element, and a current transformer for input current detection. A power supply device for a magnetron, in which all parts of the device are connected on a single radiator and molded with synthetic resin as a composite part, and the composite part and the high frequency transformer are fixed. (2) A power supply device for a magnetron according to claim 1, wherein a high frequency transformer is placed on the molded surface of the composite part, and a fastening fitting of the high frequency transformer is fixed to a radiator of the composite part.