8). It is the most liable place where microwave leakage occurs. Especially, after a long time using, the microwave leakage would enlarge at the hinge and the hook. Anyway, mechanic damage would also cause large amount of microwave leakage. Therefore, the main methods designed for preventing microwave leakage of the door are as follows:
1)Assemble a layer of steel filament or a thin metal plate with many holes at the middle of the window to made it is possible to observe the heating as well as shielding the microwave.
2)The widely used seal measurement at present is to assemble a current – resistant construct between the door and the doorframe.
“THETRANSFERING LINE
front door plate
noise filter
oven door
Fig.2-9
3. TYPICAL CIRCUIT ANALYASIS OF MICROWAVE OVEN
We have introduced the structure and the working principle of the microwave oven previously. We shall analyze the complete set circuit of the microwave oven link with the practical circuit at this chapter.
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| SCHEMATIC | DIAGRAM |
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| NOTE: Door is closed |
| MAGNETRON | ||
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| Unit is not operated | ||||
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| FA |
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| F |
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| PRIMARY |
| POWER | C |
FUSE |
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| SWITCH |
| RELAY |
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L |
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| HIGH |
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| VOLTAGE |
| MONITOR |
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| TURN- | CAPACITOR |
120V |
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SWITCH | OVEN | FAN |
| TABLE |
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60Hz |
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| LAMP | MOTOR |
| MOTOR | HIGH | |
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| L | FM | MT |
| VOLTAGE |
THERMAL |
| DIODE | ||||
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CUTOUT |
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(MAG.) | (OVEN) | MAIN |
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N |
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| RELAY |
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SECONDARY |
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| HIGH | |
SWITCH |
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| VOLTAGE |
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| TRANSFORMER |
DIGITAL PROGRAMMER CIRCUIT
LOW VOLTAGE
TRANSFORMER
10