Monday, November 15, 2010

Microwave Generation by Vacuum Tubes

Conventional tubes as triodes and tetrodes cannot be used for microwave generation. This is due to several reasons :-
- Lead inductance and inter electrode capacitance effects
- Transit time of electron from cathode to anode
- Skin effect increases losses

Microwave Oven Running Fine but Not Heating!!

I recently had a trouble with my microwave oven..
Everything seemed to be working fine except, nothing was getting heated!!!

Quite weird as  the problem may seem, it is actually a very common (and annoying, not to mention expensive) problem with microwaves..
After doing some online research I found that there could be three possible causes ...

1. Power Diode
 
 A diode is an electronic component that allows current to pass through in only one direction. Hence it is used for rectification purpose.
If the high voltage diode in the oven is damaged or short, the oven will not generate microwaves. Its is usually the most common (and thankfully also cheapest trouble).




2. High Voltage Capacitor

A capacitor is a charge storage device. It smooth-ens the  DC output. Capacitors used in microwave can operate at very high voltages and store considerable amount of charge, enough to give a lethal shock even after the equipment is switched off.

A damaged capacitor may be a possible reason why the microwave isn't working and/or making a loud buzzing noise.




3. Magnetron

A magnetron is the heart of a microwave oven. It generates high power microwaves that are guided into the microwave cavity and used to cook the food.
A defective magnetron is something that you wouldn't look forward to..
It is also the most expensive part to be replaced.

Remember never to handle a microwave oven by yourself without professional knowledge. Microwaves deal with very high voltage which can often be lethal. More on Magnetrons coming up in my next post..

Hi



Its kind of difficult to start off a blog from scratch now that I think of it..
hmm...
well anyway... lets do away with the introduction first..
I'm a final year student of Electronics and Communication engineering, currently going through the troubled phase of...  "Wat to do with my life after college!!?? O_O"

Well here I am..trying to write something out of mind after... er... wat? ages?
So.. wish me luck will ya??
gonna start posting much much more real soon..
till then... tatazzzzzzzz  ^_~