Author Topic: Why don't modern ovens keep their time after mains power failure?  (Read 3186 times)

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Offline Halcyon

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For years I've noticed that most microwave and wall ovens don't keep their time after a blackout. Both of mine are under 5 years old, yet each time the power goes out, even for a moment, the clock resets.

Why aren't they designed with super caps to keep the clock ticking for at least a few minutes?
 
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Offline Berni

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #1 on: August 31, 2018, 10:23:25 am »
Because supercaps cost money and the clocks use the 50/60Hz from the mains to get the timing from.
 
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Offline ogden

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #2 on: August 31, 2018, 10:23:39 am »
For years I've noticed that most microwave and wall ovens don't keep their time after a blackout. Both of mine are under 5 years old, yet each time the power goes out, even for a moment, the clock resets.

It's feature - blackout indicator. How would you otherwise know that blakcout happened? :-DD

Yes, it's weird that for 20 years or so kitchen appliance electronics have virtually no progress (well except capacitive sensors and "internet-connected madness").
 

Offline mikeselectricstuff

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #3 on: August 31, 2018, 10:24:03 am »
Cost. (not just the cap, but the low power circuitry needed)
It's not a feature that sells any more units.
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Offline joseph nicholas

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #4 on: August 31, 2018, 10:27:58 am »
It's a feature not a bug.  But it does seem kind of stupid not to put a supercap in there, how much more would it cost?
 

Offline mikeselectricstuff

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #5 on: August 31, 2018, 11:07:25 am »
It's a feature not a bug.  But it does seem kind of stupid not to put a supercap in there, how much more would it cost?
How many extra ovens would it sell ?
How often to power failures happen in the countries these appliances typically sell to ?
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Offline glarsson

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #6 on: August 31, 2018, 11:09:30 am »
It is not only the time that is lost. My microwave needs a complete configuration after power failure to set things like language of the display. Without a set language it just displays numbers. It doesn't even default to English. Expected better from such an expensive name brand unit.
 
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Offline Alex Eisenhut

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #7 on: August 31, 2018, 11:15:45 am »
Noticed that a long time ago too! There used to be frequent blackouts here until they sealed up the underground transformer properly.

It is frustrating, but rather than find a simple solution I think the way forward is an i7 with webcam in every appliance that runs unpatched Windows, so it can get the time from NTP. Then within two hours of being plugged in people are downloading your high school pics from your toaster oven.

Progress.
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Offline David Hess

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #8 on: August 31, 2018, 11:22:04 am »
They are just cheap in the quality sense.  They all use a limited number of mass produced controllers and none of them support clock and memory backup.

As far as how often blackouts are, in my experience the number per year has been increasing for decades.  Where I live now, we get at least three a year and two will be hours long.
 

Online Zero999

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #9 on: August 31, 2018, 12:13:57 pm »
Do they make IoT microwaves? They wouldn't suffer from this issue. Of course until it's hacked so the magnetron only turns on when the door is opened and you're fried.  >:D
 

Offline xrunner

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #10 on: August 31, 2018, 12:22:14 pm »
It's a power-failure notification feature. If you are gone from the house, you will know if a power failure happened. Important information easily displayed for you.
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Offline BradC

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #11 on: August 31, 2018, 12:42:34 pm »
Every appliance I've owned with some form of backup, from a pool filter timer to a standard oil heater has required repair or replacement of the backup source (battery or capacitor) long before the appliance might have reached the end of its useful life. The sort of intervention that had I not been handy with a soldering iron, would have seen it on the kerb and the wife off to buy a new one.

I'd rather have an appliance last >30 years and suffer the inconvenience of having to set the clock a couple of times a year.
 

Offline joseph nicholas

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #12 on: August 31, 2018, 02:45:52 pm »
It probabily the annoyance factor that companies love to embrace.  When something is a constant irritant it sticks in your mind but as time goes by you tend to forget it was annoying and just remember the products manufacture's brand name.  But of course all modern microwave ovens use the same chip to control itself.  This market is extremely competive with lots of sales.  They all act the same way.  Almost nobody, rich or poor fixes a broken microwave, they just throw it out and buy a new one.
 

Offline Mr. Scram

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #13 on: August 31, 2018, 02:53:39 pm »
Now you have a very accurate and reliable clock, bar outages. Otherwise you'd have a more expensive clock that could run fast or slow and has caps that can go bad.

I prefer the dumb, cheap and reliable option.
 
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Offline David Hess

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #14 on: August 31, 2018, 04:20:59 pm »
Everybody here likely has one or several ubiquitous examples where this was a solved problem going back decades.  The battery backed up clock and CMOS RAM inside most PCs does everything needed with a replaceable CR2032 battery.

Consumer appliances are just cheap.

 

Offline hermit

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #15 on: August 31, 2018, 04:29:36 pm »
As someone who used to work in that industry in the repair field let me give you the 'real answer' as it was given to us.  You ever fix something by unplugging it to clear the corrupted memory?  A battery would prevent this. So, consumers are going to gripe about resetting the time or the 'complex' method of clearing the memory.  Often they would get charged for this by a repair person.
 

Online nfmax

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #16 on: August 31, 2018, 04:43:12 pm »
The OP asked the wrong question. It should have been: "Why do modern ovens require the damn clock to be set before they will cook anything?"
 

Offline mzzj

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #17 on: August 31, 2018, 05:01:32 pm »

How many extra ovens would it sell ?
How often to power failures happen in the countries these appliances typically sell to ?
THIS.

Supercap or battery is probably already dead before the first power outage  ;D
In last 10 years we have had one or two power outages so its not really a selling point for me...on the other hand my parents home on countryside has power outages couple of times each year.
 

Offline David Hess

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #18 on: August 31, 2018, 05:14:45 pm »
The OP asked the wrong question. It should have been: "Why do modern ovens require the damn clock to be set before they will cook anything?"

Mine do not but both of my microwave ovens are on their second high voltage ballast capacitor.
 

Offline factory

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #19 on: August 31, 2018, 05:36:01 pm »
Another unwanted feature to look for if I have to replace either of them, I don't bother with the clock on the Microwave and the oven is gas (I use a 60min clockwork timer for that). Both are switched off at the wall when not in use and not left unattended when in use.

The only kitchen appliance that stays on is the fridge/freezer, everything else would just waste energy.

David

PS, We have had quite a few short power cuts this year.
 

Offline tom66

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #20 on: August 31, 2018, 05:49:19 pm »
It is not only the time that is lost. My microwave needs a complete configuration after power failure to set things like language of the display. Without a set language it just displays numbers. It doesn't even default to English. Expected better from such an expensive name brand unit.
Not quite as bad as my Panasonic inverter combi microwave oven.

It has a grill, and three power levels.  It also has a six character display.

So, to display the grill power level, it shows "GRILL " followed by "RILL 1".  That is, it scrolls a seven character message because it will not fit on the six character LCD.  And you need to wait three seconds every time for it to start scrolling,  *every* time you change the power level.

Nothing would have stopped them abbreviating it to GRL 1,  or even just removing the space there...but nope.   It scrolls the message.  It's infuriatingly bad design and I encounter it on an almost weekly basis.  I can guess the power level by pressing it a few times,  but sometimes I'll miscount -- so  I'll have to wait for it to tell me the setting.
 

Online PA0PBZ

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #21 on: August 31, 2018, 06:12:46 pm »
I don't understand why you would even have a time display on a microwave, do you also have one on your coffee maker, fridge, mixer? If I don't set the clock on my microwave the display just stays dark when not in use, the way it should be.
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Offline glarsson

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #22 on: August 31, 2018, 06:19:26 pm »
I don't have any use of the clock on the microwave. Luckily it doesn't flash 00:00 when not set or show any other time, it only shows :. However, it does not display text menus unless the language is set. Ok if you know what menu number 16 of 17 does.
 

Offline steve30

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #23 on: August 31, 2018, 06:22:37 pm »
Not quite as bad as my Panasonic inverter combi microwave oven.

It has a grill, and three power levels.  It also has a six character display.

So, to display the grill power level, it shows "GRILL " followed by "RILL 1".  That is, it scrolls a seven character message because it will not fit on the six character LCD.  And you need to wait three seconds every time for it to start scrolling,  *every* time you change the power level.

Nothing would have stopped them abbreviating it to GRL 1,  or even just removing the space there...but nope.   It scrolls the message.  It's infuriatingly bad design and I encounter it on an almost weekly basis.  I can guess the power level by pressing it a few times,  but sometimes I'll miscount -- so  I'll have to wait for it to tell me the setting.

I've had a Panasonic machine for years and have always noticed this silliness. It never really bothers me though; probably because I tend to count the beeps. one beep for grill 1, two beeps for grill 2, three beeps for grill 3.

Personally I would have thought they'd have named them the other way round, with 1 being the lowest power and 3 being the highest.
 

Offline Halcyon

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Re: Why don't modern ovens keep their time after mains power failure?
« Reply #24 on: September 01, 2018, 12:39:02 am »
It's a power-failure notification feature. If you are gone from the house, you will know if a power failure happened. Important information easily displayed for you.

I guess some people look at it that way, but I don't see how it would help the regular consumer?

I've had two brief power failures in two weeks due to wind/weather and other than "oh great, the power went out", I don't know when it occurred or for how long. It's not really all that useful.

Besides, I already have an elaborate power failure notification system: My NAS needs the crypto password before I can access it again. ;-)

My Sharp microwave oven isn't too much of a bother to me. When the clock resets, the LCD just displays "0" (for no time left on the cooking timer). It's logical, I can live with that. It doesn't flash away at some arbitrary time like my wall-oven does.
 


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