GB2328851A

GB2328851A - Microwave oven capacitor mounting

Info

Publication number: GB2328851A
Application number: GB9808971A
Authority: GB
Inventors: Jang-Gun Lee
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 1997-08-25
Filing date: 1998-04-27
Publication date: 1999-03-03
Also published as: GB9808971D0; CN1209524A; KR19990009692U; JPH1172233A

Abstract

A high voltage capacitor (145) of a microwave oven is mounted to a wall of an electronic component compartment (140) by a bracket (150). The bracket (150) holds the capacitor (145) away from the wall (113) and allows cooling air to circulate behind it. Overheating due to heat conducted through the wall from the heater 122 is avoided.

Description

Microwave Oven Description The present invention relates to a microwave oven.

A microwave oven is a cooking appliance that cooks food using the heat generated by food molecules which are excited by microwaves.

Figure 1 shows an exploded view of a known microwave oven. Figure 2 shows an enlarged view of an electrical component compartment of such an oven.

Referring to Figures 1 and 2, the known microwave oven comprises an inner case 12, which defines a cooking chamber 20, and an outer case 11, which defines an exterior of the oven. Hinge members (not shown) attach a door 30 that allows access to the cooking chamber 20 to the front of the oven. Food is placed on a cooking tray 21 that sits on a bottom surface of the cooking chamber 20. Cooking selections can be made by a user through a control panel 31.

A partition wall 13 separates an electrical component compartment 40 from the cooking chamber 20. Various electrical components, necessary for the generation and radiation of microwaves, are placed in this compartment 40. These components include a transformer 42 for stepping-up a voltage supplied from an external electric power source and a capacitor 45 for storing the stepped-up voltage. A magnetron 41, powered by the high voltage supply from the capacitor 45, generates microwaves which are radiated into the cooking chamber 20. A fan 43 cools the electrical components by drawing in external air and a guide duct 44 directs air from the compartment 40 into the cooking chamber 20. A heater 22, used for the grilling of food, is placed in the roof of the cooking chamber 20.

During operation of the oven, the heater and electrical components, such as the transformer, generate a large amount of heat. This can damage the capacitor, so shortening its lifetime and causing it not to function properly.

It is an aim of the present invention to ameliorate this problem.

According to the present invention, there is provided a microwave oven having an electrical component compartment comprising a capacitor, wherein the capacitor is mounted to a wall of the compartment in such a way as to be positioned away from the wall.

Preferably, the capacitor is mounted to the wall by a bracket.

More preferably, the bracket is bridge-shaped and comprises a rectangular panel, twice bent at opposing ends, each pair of bends perpendicular to each other so as to form L-shaped legs.

Preferably, a space is formed between the capacitor and the wall, through which air may flow.

Preferably, the electrical component compartment comprises a fan for cooling electrical components therein, a transformer for stepping-up an input voltage, a capacitor for smoothing the stepped-up voltage and a means of generating microwaves powered by the smoothed, stepped-up voltage.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an exploded view of a conventional microwave oven; Figure 2 is an enlarged view illustrating the electrical component compartment of the microwave oven shown in Figure 1; Figure 3 is an exploded view of a microwave oven according to a preferred embodiment of the present invention; and Figure 4 is an enlarged view illustrating an electrical component compartment shown in Figure 3.

Referring to Figures 3 and 4, the microwave oven comprises an inner case 112, which defines a cooking chamber 120, and an outer case 111, which defines an exterior of the oven. Hinge members (not shown) attach a door 130 that allows access to the cooking chamber 120 to the front of the oven. Food is placed on a cooking tray 121 that sits on a bottom surface of the cooking chamber 120. Cooking selections can be made by a user through a control panel 131.

A partition wall 113 separates an electrical component compartment 140 from the cooking chamber 120. Various electrical components, necessary for the generation and radiation of microwaves, are placed in this compartment 140. These components include a transformer 142 for stepping-up a voltage supplied from an external electric power source and a capacitor 145 for storing the stepped-up voltage. A magnetron 141, powered by the high voltage supply from the capacitor 145, generates microwaves which are radiated into the cooking chamber 120. A fan 143 cools the electrical components by drawing in external air. A guide duct 144 directs air from the compartment 140 into the cooking chamber 120, displacing moisture and odours.

A heater 122, used for the grilling of food, is placed in the roof of the cooking chamber 120.

The capacitor 145 is easily damaged by heat generated by the heater 122 and the other electrical components, such as the transformer 142. The heat is transmitted through the walls of the electrical component compartment 140. To reduce the amount of heat reaching the capacitor 145, the capacitor 145 is fixed to a bracket 150, mounted on the partition wall 113 of the electrical component compartment 140. The bracket 150 separates the capacitor 145 from the partition wall 113 by a predetermined distance, so preventing the capacitor 145 from being damaged by heat.

The bracket 150 comprises a front portion 151 on which the capacitor 145 is fixed, stepped portions 152 bent perpendicularly along longitudinal sides of the front portion 151, and fixing portions 153 bent outwardly and perpendicular to the stepped portions 152. The fixing portions 153 are mounted on the partition wall 113.

Accordingly, a space 154 is formed between the front portion 151 of the bracket 150 and the partition wall 113 by the stepped portions 152.

Thus, the heat transmitted to the capacitor 145 is minimised, since the capacitor 145 is positioned away from the partition wall 113 by the stepped portions 152 Additionally, the capacitor 145 is cooled more efficiently, because air passes through the space 154 formed between the partition wall 113 and the front portion 151 of the bracket 150.

The operation of the microwave oven will now be described.

When power supplied to the microwave oven, the input voltage is stepped-up by the transformer 142, which in turn charges the capacitor 145. The magnetron 141, powered by the capacitor, produces microwaves and radiates them into the cooking chamber 120, cooking the food contained therein. The microwave oven may also use the heater 122 to grill the food at the same time.

During operation of the oven, air is drawn into the electrical component compartment 140 by the fan 143, to cool the components. However, it is often the case that the fan 143 does not sufficiently cool the electrical components, since they are in thermal contact with the walls of the electrical component compartment 140.

The capacitor 145 is prevented from being damaged by heat, because it is positioned away from the partition wall 113 by the bracket 150.

It will be appreciated that many modifications can be made to the embodiment described above.

Claims

1. A microwave oven having an electrical component compartment comprising a capacitor, wherein the capacitor is mounted to a wall of the compartment in such a way as to be positioned away from the wall.

2. A microwave oven according to claim 1, the capacitor is mounted to the wall by a bracket.

3. A microwave oven according to claim 2, wherein the bracket is bridge-shaped and comprises a rectangular panel, twice bent at opposing ends, each pair of bends perpendicular to each other so as to form L-shaped legs.

4. A microwave oven according to any preceding claim wherein a space is formed between the capacitor and the wall, through which air may flow.

5. A microwave oven according to claim 1, wherein the electrical component compartment comprises a fan for cooling electrical components therein, a transformer for stepping-up an input voltage, a capacitor for smoothing the steppedup voltage and a means of generating microwaves powered by the smoothed, stepped.

up voltage.

6. A microwave oven having an electrical component compartment, a fan for drawing external air into the electrical component compartment and cooling electrical components disposed therein, a transformer installed in the electrical component compartment for increasing a level of voltage applied from an external electric power source, and a capacitor in which voltage increased by the transformer is charged, said microwave oven comprising: a bracket mounted on a wall of the electrical component compartment for fixing the capacitor, said bracket separating the capacitor from the wall of the electrical component compartment.

7. A microwave oven of claim 6, wherein said bracket comprises a front portion on which the capacitor is fixed, stepped portions bent perpendicularly along longitudinal sides of the front portion, and fixing portions bent outwardly and perpendicular to the stepped portions.

8. A microwave oven of claim 7, wherein a space, through which external air drawn by the fan passes, is formed between the front portion of the bracket and the wall of the electrical component compartment on which the bracket is mounted.

9. A microwave oven substantially as hereinbefore described with reference to Figures 3 and 4.