Author Topic: How do microwave transformers last so long?  (Read 3422 times)
F96T12 DD VHO
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Just chilling I guess


https://www.facebook.com/ Unreleasedwav UC2Uv7t9KgigOoT6blff2t3w i.d._official
How do microwave transformers last so long? « on: October 18, 2018, 05:23:48 PM » Author: F96T12 DD VHO
I use mine like everyday and the combined time is like 8 hours on end! I just wanna know why they last for so long.
Logged

Music Producer/Light Enthusiast

Medved
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Re: How do microwave transformers last so long? « Reply #1 on: October 19, 2018, 01:24:32 AM » Author: Medved
They very rarely get hot, just because they are heavy and on for only few minutes with way longer for cooling.
Plus even when the microwave is 10+ years old, the actual runtime is barely few 100's hours. If you are using it in some business activity really heavily, still it reaches few k-hours. At that time many other parts on the microwave fail way sooner and with many from these it is not economical to replace or even their failure makes the thing unsafe even after repairs (rusted case, broken magnetron sputtering berylium ceramics around, broken magnets,...)

Compare that with lighting use, where 10 years in street lighting means 36k hours and majority of that close to the top temperature rating, yet even there the prime failure/replacemects cause uses to be corrosion and system becoming outdated and not the ballast failing alone...
Logged

No more selfballasted c***

MissRiaElaine
Guest
Re: How do microwave transformers last so long? « Reply #2 on: October 19, 2018, 02:46:28 PM » Author: MissRiaElaine
Added to that is the fact that a transformer is a static device, with no moving parts. Provided it's in an environment where it isn't getting too hot and has adequate ventilation and/or cooling, there's not a lot to go wrong. Ballasts in street lamps have been known to last 40 years and up.
Logged
tolivac
Member
*****
Offline

View Posts
View Gallery

Re: How do microwave transformers last so long? « Reply #3 on: October 20, 2018, 03:39:20 AM » Author: tolivac
There have been Microwave transformer failures from a shorted rectifier diode,cap or magnetron.They can fail.Early magnetron tubes had glass envelopes rather than ceramic.If the ceramic is intact-no hazard.Now if its broken from someone trying to salvage the magnet than its a hazard.You don't want to get cut by the fragments or breathe its dust.Best to leave the ceramic tubes intact.Tube collectors may get a kick out of them.Transmitter tubes have the same ceramic case.so we just replace them and let the rebuilder deal with it.The large transmitter tubes can be rebuilt-the envelope opened-bad parts-filament,and other replaced the tube reassembled,repumpted and tested for reuse.
Logged
Medved
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Re: How do microwave transformers last so long? « Reply #4 on: October 20, 2018, 04:37:05 AM » Author: Medved
There have been Microwave transformer failures from a shorted rectifier diode,cap or magnetron.They can fail.

What I wanted to say it is usually not the transformer to fail first, but very often the transformer fails as victim of the other parts failure.
Most frequently the capacitor fails as first, which then fries the diode and the HV fuse (in case of a short circuit failure). The secondary open circuit means there is no capacitive reactance load, so the primary gets overloaded by the inductive reactance current imposed by the core design (normally designed to cancel out the capacitive load nature).
Other sequence frequently occuring is the capacitor loosing capacitance, leaving extra inductive reactance on the primary so overloading it, plus the reduced magnetron power (because of the lower current feed) makes the user to operate the thing longer.
Rarely the magnetron goes away, but I've seen just one occassion and even that was more likely caused by overheating magnets loosing field because of mess accumulation on the cooling fins and on the fan.
These then end up very often by fried MOT, but can not be counted as MOT caused failures.
Logged

No more selfballasted c***

Cole D.
Member
*****
Offline

View Posts
View Gallery

123 V 60 CPS


Dk944Mr-jX4jbnoUUj7xAw
Re: How do microwave transformers last so long? « Reply #5 on: October 20, 2018, 11:16:34 PM » Author: Cole D.
I heard microwave popcorn is bad for microwaves, because there isn't enough matter to heat, so the magnetron overheats.
Logged

Collect vintage incandescent and fluorescent fixtures. Also like HID lighting and streetlights.

Medved
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Re: How do microwave transformers last so long? « Reply #6 on: October 21, 2018, 12:53:29 AM » Author: Medved
I heard microwave popcorn is bad for microwaves, because there isn't enough matter to heat, so the magnetron overheats.

If you do that in the bags designed for microwaving it (the "microwave popcorn" is sold in thse), it is OK. These bags have build in resistive metallic layer designed to absorb the microwaves and turn them into heat. Yes, it is then just using a disposable pan heated by a lossy magnetron, but for the magnetron it is OK.
Worse would be if someone attempts to make the popcorn without those bags, that will overheat the magnetron. But reasonable microwave designs should count for that and feature proper protection. But still it is a stress for the components involved...
Logged

No more selfballasted c***

Mandolin Girl
Guest
Re: How do microwave transformers last so long? « Reply #7 on: November 03, 2018, 02:42:47 PM » Author: Mandolin Girl
We've had our current microwave for well over ten years and the only reason we will be replacing it later on in the year is next to our new  cooker it is looking past its best.

Logged
Men of God
Member
***
Offline

Gender: Male
View Posts
View Gallery


jiachao.wei.71 chao_813975447 UChyTpXvlQ8ZCfBPP_lJjubg chao990613
Re: How do microwave transformers last so long? « Reply #8 on: November 19, 2018, 04:22:03 AM » Author: Men of God
这在中国是不存在的,因为中国的微波炉变压器大部分都是铝制线圈的,很快就会烧毁。。
Logged

我不会英文,所以我用中文,请你们用翻译网站翻译我打的字!

I can't in English, so I in Chinese, please use the translation website to translate my words!

Bert
Member
**
Offline

Gender: Male
View Posts
View Gallery


Re: How do microwave transformers last so long? « Reply #9 on: November 23, 2018, 07:44:05 PM » Author: Bert
I still use an Amana RadaRange from the mid 70's. Has a couple dials rather than a touchpad and digital display. It is built like a tank compared to anything modern, it weighs about 80 pounds. The new ones have undersized transformers that still perform OK, but the old ones will run for hours without getting very hot.
« Last Edit: November 23, 2018, 07:46:45 PM by Bert » Logged
Print 
© 2005-2024 Lighting-Gallery.net | SMF 2.0.19 | SMF © 2021, Simple Machines | Terms and Policies