background image

-Give enough time to the meals to get hot. There are some parts which need

more time.

-The meals should not be served directly from the microwave oven. When

you leave them covered for some minutes, the heat can better balance

itself.

-Thick slides of meat, for example, are mostly hotter outside than inside.

-Round cylindrical parts of food with a diameter of 20 to 50 mm, however,

-If possible, defrost frozen and unpacked meat in a glass or porcelain

container. At best on a drain plate, so that a liquid that arises during the

defrosting can flow off.

-Instant meals in aluminium plates or plastic containers

with metal-coated cover foils (of course, prick it!) can

be heated in the microwave oven as far as the

producer explicitly indicates it on the packing.

-The picture on the left demands ”give it into a dish”.

Therefore unpack it!

-Information of food producers, however, are not always

an ”excuse”.

For the end, some well-aimed advises for the consumer

tend to become hotter inside than outside.

-Basically, packing material and especially metal foils should be removed

before the cooking.

-However,  if  the  shielding  effect  is  intended,  you  have  to  stick  to  a

distance of 2 cm to the oven wall, that no sparks will jump over.

-As these meals get cooked very fast, a lot of steam will arise. When the

meals are covered (only loose!), nothing will fall down in the oven.

-The heat within covered meals is spreading better.

-Covered meals do not dry up so fast.

-When an over-baking is intended, the food should not be

covered.

-When using the grilling function, of course nothing should be

covered as well!

-Liquid meals should be stirred from time to time.

-Add some water to harder vegetables (e.g. carrots).

-It is not necessary to add liquid to softer vegetables (e.g.

tomatoes).

-It is advantageous to turn defrosting food, if possible, after the half

defrosting time.

-If possible, do not defrost the food completely with microwave energy. Thus you can avoid

irregularities (dry rims).

-Basically,  do  not  defrost  in  the  packing  material.  It  makes  no

difference  whether  board,  paper  or  plastics  –  not  in  metal

anyway.

-Fruits and vegetables should also not be defrosted completely in

the microwave oven, if it is not further used immediately. Some

room temperature at the end of defrosting is good for the taste.

-If  required,  fruits  and  vegetables  can  however  be  cooked  ready

directly  from  the  frozen  condition.  Naturally,  capacity  and  time

have to be adjusted.

created by  TSE-N,  Reiner Kurzke

Page 28

Содержание In General

Страница 1: ... 135 D 90429 Nürnberg Germany Fax 49 0 911 323 1420 TSE N Publ Nr 599 510 968 03 2001 MICROWAVE OVENS IN GENERAL Trainingsunterlagen EN Ausgabe Microwave Ovens in general Fundamentals Measuring technique Fault finding created by TSE N Reiner Kurzke Page 1 ...

Страница 2: ...19 Measurements in practice 20 Voltage measurement Easy Way Measurement of capacity levels 21 Rules for leaky rays Measurement of leaky rays 22 Checking of the interlock door safety system Measuring the fuse diode Checking the high voltage diode 23 Measuring the magnetron Measuring the high voltage capacitor Checking the high voltage transformer 24 Fault finding trees 25 Fault finding tree 26 Faul...

Страница 3: ...ectrum time saving cooking speed the taste natural flower healthy cooking no fat used no loss of vitamins energy saving no pre heating time saving speed quick and problem free defrosting less washing up foot cooked in the serving dish easy to clean easy to use Frequency Microwaves are in the nonionizing range They therefore also do not have anything to do with radioactivity Radioactivity can only ...

Страница 4: ...arks or when the waves have a retrospective effect on the magnetron to a damaging of its anode Therefore never use an empty microwave oven Interpenetration Many materials let microwaves pass through without that they react themselves glass porcelain pottery plastic suitable for microwaves and paper board dry This is used during the microwave operation The waves can penetrate into the food without ...

Страница 5: ... BE USED IN THE MICROWAVE OVEN Suitable Ovenware O suitable non suitable 1 excluding silver gold platinum or metal decoration 2 does not include glaze containing metal 3 please note the maximum temperature stated by the manufacturer created by TSE N Reiner Kurzke Page 5 ...

Страница 6: ...soups should be stirred for a change for the same reason This helps to distribute the heat and prevents too high temperatures on the surface In the extreme case this could attack the upper edge of the material when using plastic containers In any food positively negatively charged liquid molecules are accidentally arranged in disorder If we now put this food into an electromagnetic field these mol...

Страница 7: ...r flow of the fan is partly used in order to operate the wave agitator by it Various ways of feeding and distribution of microwaves Using turntables guarantees a good distribution of waves for the food Guiding of Waves Oven with stirrer 1 Bottom Plate 2 Housing 3 Cooking Area 4 Sheet 5 Stirrer 6 Microwave Input 7 Duct 8 Anode 9 Magnetron 10 Ventilator 11 High Voltage Transformer Oven without stirr...

Страница 8: ... 15 seconds ON and 15 seconds OFF The timing cycles can differ a little bit due to the different types electronic timer the principle is always the same Thus 10 of these cycles will pass within 5 min Following important note Never switch on a microwave oven without energy absorbingfoodintheoven Ifdespite that microwave energy is fed to an empty oven these waves work off their energy where it is no...

Страница 9: ...nic with a display Instead of a controller it is also possible to use input fields Hereisatypicalportray of the control panel from an instruction manual Just with appliances controlled by electro nics you can find the most different equip ment features and pro grammes The basic function of the microwave oven is on the whole always the same Input Control Panels created by TSE N Reiner Kurzke Page 9...

Страница 10: ...n the microwave oven In this connection one has to observe that the microwave energy only affects the food from above and that the required cooking duration will thereby be extended Furthermore a distance of 2 cm to the oven wall must be kept to in order to avoid a sparkover Aluminium foil wrapped around thinner parts such as ends of poultry legs shields the microwave energy and thus prevents a to...

Страница 11: ...Wiring diagram of a timer controlled microwave oven The various sections are explained on the following pages created by TSE N Reiner Kurzke Page 11 ...

Страница 12: ...ening the door all 3 microswitches are actuated via at least two mechanical systems In doing so primary and secondary switches interrupt the power supply If for whatever reason one of these switches does not open the monitoring switch short circuits the entry circuit resp high voltage transformer The triggering off of the fuse is hereby accepted Safety first Mechanical safety system primary second...

Страница 13: ...interlock safety system can have a different view from one model to the other when looking first at the wiring diagram The basic functions are always the same Interlock Safety System created by TSE N Reiner Kurzke Page 13 ...

Страница 14: ...ing with each other see under Electr safety system More elements such as the overheat thermostat for the magnetron can be installed depending on the model thermostat of oven grilling or air duct The suppressor filter is blocking high frequencies and demanded by law The function of the secondary and or high voltage circuit is explained on the following pages Primary Circuit Secondary Circuit create...

Страница 15: ...arts are indispensable for the prevention of vibrations to the casing If the primary winding is supplied with a mains voltage of 230 V following voltages are induced into secondary windings 3 1 V as low voltage directly connected with the heating winding of the magnetron for heating the cathodes 2 750 V as high voltage connected with the voltage doubling High Voltage Transformator created by TSE N...

Страница 16: ...voltage of the secondary winding of the high voltage transformer are converted into over 4 000 Volt DC voltage That operates the magnetron After the oven has been switched on the first positive wave charges the capacitor with more than 2 000 Volt After the polarity has been changed the diode avoids that the capacitor is discharging The voltage of the positive half wave is added to the charge of th...

Страница 17: ...AK Diode created by TSE N Reiner Kurzke Page 17 ...

Страница 18: ...uter cylinder The magnetron requires a high DC voltage 4 000 Volt a low AC voltage for the heating of cathodes and a magnetic field to be able to work The cathode is heated in order to cause the electrons emitting so that they will flow to the anode In order to achieve the oscillation one needs a permanent magnet Because of its magnetic field the electrons are moving in an orbit round the cathode ...

Страница 19: ...s from the outside In case of measurements or repairs PULL THE MAINS PLUG By all means discharge the high voltage capacitor before This must be made by suitable lines with isolated peaks With every microwave oven it is necessary to carry out a high frequency leakage check measurement of leaky rays and the checking according to VDE 0701 after a repair the mere opening of the oven is also a repair M...

Страница 20: ...50 off 50 capacity 30 on 70 off 30 capacity Useful clock cycle 30 seconds 1 liter water 17 24 62 seconds full capacity Measurement of capacity simple version Important Use a container with thin material Thick container walls extract parts from the water of the rising heat and falsify the measuring result If possible initial temperature 20 C Exact time measurement An exact thermometer if possible a...

Страница 21: ...it in the middle of the oven Close door Timer to 3 minutes Capacity to 100 Start oven For use of the measuring device see its operational manual Check the leaky rays by moving the test probe from right above clockwise starting at the door not faster than 25 mm sec back to the initial position The measurement must be made in a distance of 5 cm Styrofoam distance pieces or other distance pieces are ...

Страница 22: ...s Disconnect the mains plug before any measurement Short circuit the capacitor with suitable isolated means and thus discharge it Check the fuse diode in both directions for passage An intact fuse diode must LOCK in both directions Unplug the oven from the mains Ensure that the capacitor is discharged Disconnect the diode for measurement Measure in both directions using an ohmmeter with the highes...

Страница 23: ...f the casing must be infinite Measuring the high voltage capacitor Small resistance increasing fast ok Small resistance remaining short circuit Very high resistance remaining interruption In the case of a capacitor exchange please use by all means the original capacitor The correct function and the values depend to a great extent on the exact capacity Measuring the magnetron Checking the high volt...

Страница 24: ...r controlled microwave ovens Mains voltage existing timer in function door closed Fault finding tree of timer controlled microwave ovens Mains voltage existing timer in function door closed created by TSE N Reiner Kurzke Page 24 ...

Страница 25: ...Fault finding tree of timer controlled microwave ovens Mains voltage existing timer in function door closed created by TSE N Reiner Kurzke Page 25 ...

Страница 26: ...Fault finding tree for microwave ovens No microwave capacity fan is running created by TSE N Reiner Kurzke Page 26 ...

Страница 27: ...Fault finding tree for microwave ovens No function no reaction to any entry created by TSE N Reiner Kurzke Page 27 ...

Страница 28: ...ou have to stick to a distance of 2 cm to the oven wall that no sparks will jump over As these meals get cooked very fast a lot of steam will arise When the meals are covered only loose nothing will fall down in the oven The heat within covered meals is spreading better Covered meals do not dry up so fast When an over baking is intended the food should not be covered When using the grilling functi...

Страница 29: ...ss cooking of food rather less 600 W defrosting and heating of frozen foods heating of one pot courses 500 W finish cooking of hot pots cooking of egg dishes 450 W continued cooking of meals 350 W cooking of sensitive food heating of baby food 250 W swelling up of rice melting of gelatine 150 W defrosting of meat fish bread 80 W defrosting of cheese cream butter raise the yeast dough preheating of...

Отзывы: