Is my megnatron working or not???

[Electronics_chaitanya]

Hello everyone



Recently i bought old microwave oven after checking HV caps and HV diodes when i check megnatron it shows about 1 to 0.9 ohms across its filament terminals so can u tell me that is it working or not???? as well as also sugeest me any circuit to start megnatron extranally from microwave oven.......




-------------regards

 

[betwixt]

The resistance is probably correct but DO NOT EVER EVEN THINK of starting a magnetron outside of an oven casing.
The radiation from them is invisible and can seriously injure you or kill you in less than a second. You don't get a second chance !!!

They also work at extremely high voltages without current limiting so if you touch any connections, even if the radiation doesn't kill you, the voltage will.

Brian.

 

[Electronics_chaitanya]

Hello


Thanks for your advice but i know about the effect of radiation and see much of images on internet but actually i just want to check my magnetron....my HV diodes are working ok....i measure capacitance of HV capacitor in meter it is also ok...MOT is working perfectly.......so i cant understand what is the problem......


-Regards

 

[betwixt]

You need to establish if the HV is actually there. Use a neon lamp or a neon screwdriver and hold it near to the HV cables to the magnetron. Under no circumstances actually touch any of the connections. The neon should glow when you get to about 1cm from the cables. If it does, you can assume the HV is present and you then need to check the LV to the filament. This isn't easy because the LV is connected to the HV. The safest way to measure is to stop the fan rotating and operate the oven for about 20 seconds. Unplug from the power socket and feel the fins on the magnetron. They should be warm, if they are, the filament supply is probably working.

It is possible the magnetron has failed, especially if the oven is more than a few years old. They gradually reduce power until they reach a point when they can no longer oscillate, if it has failed, your only option is to replace it.

Brian.

 

[Electronics_chaitanya]

hello


Thank you for your advice sir.....Magnetron is failed and i replace it now oven is working perfectly.....-




-Regards