electronics

How a microwave oven works 

The Revolution of cooking

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1. A microwave oven is made up of three essential parts
   
   magnetron
   transformer
   capacitor
   
   All microwaves have these parts ,they all have different door switches,thermostats and front panels
   and casings
   I will now explain the major components
   magntetron
   transformer
   capacitor
   
   All microwaves have these parts ,
   They all have different door switches,thermostats and front panels
   and casings
   I will now explain the major components
2. Magnetron
   
   There are four parts a magnet ,coil,wave guide and of course the cooling fins
   The coil is at the back it recieves pulses of energy from its input or anode.The magnet emits a strong magnetic field .When the coil is energized the magnetic field is energized the opposite direction and starts giving off electrons
   
   The wave guide takes the electrons and moves them out of the magnetron. The cooling fins are situated around the wave guide as it gets very hot
3. TRANSFORMER
   
   The transformer is made up of a primary and secondry
   the primary is powered by 220 AC The secondry puts out about 1100v.There is a seperate winding for the magnetron
   
   CAPACITOR
   
   The capacitor feeds straight off the secondry It is neccesary to convert ac to dc and add a pf of 1, connected is a high power diode going to earth which supplies the pulse for the magnetron to work
4. HOW TO TEST THE HIGH VOLTAGE DIODE
   
   Unplug the oven.
   DISCHARGE ALL HIGH VOLTAGE CAPACITORS. (Procedure)
   Carefully remove the lead that goes to the capacitor (the ground connection may remain attached)
   Set the ohmmeter to read ohms at a scale of R X 10,000 or higher.
   Measure the resistance across the terminals of the diode by touching the positive meter probe to the anode and the negative probe to the cathode (the cathode is the side that goes to ground, usually marked by an arrow, dot or stripe).
   A normal diode, depending on make and model, should read about 50,000 to 200,000 ohms.
   (Note:The polarity of the meter probes, with regard to forward and reverse bias readings, may be relative to the type of meter being used.)
   Reversing the leads should produce a reading of infinity (open), unless there is a bleeder resistor across the diode, in which case the reading would show the [megohm] value of the resistor.
   If continuity is read in both directions, the diode is shorted. If infinity is read in both directions, the diode is open. In each case the diode must be replaced.