Oven and microwave clocks gaining time quickly

[Targarama]

Here in Muscat our house seems to have good electrikery, but I've noticed our oven and microwave clocks have recently started gaining 10 minutes a week. I set them when I powered them up when we came out here (2nd home) on 6th Oct. They are both 30 mins fast now.

Do you think this is an issue with the frequency/hz of the electricity supply (210-230v 50hz like the UK btw). The appliances are AEG and are top quality. The oven has always cooked incredibly quickly, but I don't that that is related.

Any ideas?

[bga]

IIRC it is a bad attempt by AEG to account for Omani stretch time.

I'll ask my dad if he gets the same, he's living in Muscat at the moment.

[HoHoHo]

We have two ovens and a microwave in our kitchen here in wet West Sussex. All three are Miele and all three have since day one been unreliable at keeping time to the point where I haven't bothered setting them for some years, and I let them do their own thing.

Not only do they seem to be able to move forward, it at differing rates as well!

Thought it was simply the voltage in my house, possibly not!

[Engineer1]

The time could be that it is taking it's "seconds" pulse from the mains frequency, 50 pulses is one second, if the power being transmitted is closer to 60hz then each second will be 5/6 of a second and so on, usually this sort of thing only happens on smaller grids.

[grumbledoak]

I cannot imagine that it is the mains frequency. Quartz watches are dirt cheap and they don't have any mains feed at all.

[Targarama]

Engineer1 said:

The time could be that it is taking it's "seconds" pulse from the mains frequency, 50 pulses is one second, if the power being transmitted is closer to 60hz then each second will be 5/6 of a second and so on, usually this sort of thing only happens on smaller grids.

This is what I think is happening.

[HoHoHo]

Targarama said:

Engineer1 said:

The time could be that it is taking it's "seconds" pulse from the mains frequency, 50 pulses is one second, if the power being transmitted is closer to 60hz then each second will be 5/6 of a second and so on, usually this sort of thing only happens on smaller grids.

This is what I think is happening.

Does that mean we're on a 'smaller grid' here in this part of West Sussex?

[jet_noise]

Dear Targarama,

when I designed some cooker controllers ('twas in the late 80s mind) the clock did indeed take it's timebase from the mains frequency. Usually this is pretty accurate long term but, especially in times of high/low demand and if the power station controller is not on the ball the frequency can drift.

Why do it this way?
Cheap and every penny counts in white goods. A resistor may be the only additional component you need to get the signal into a microcontroller and that saves a few pennies compared to a crystal & loading caps,

regards,
Jet

[grumbledoak]

jet_noise said:

Why do it this way?
Cheap and every penny counts in white goods. A resistor may be the only additional component you need to get the signal into a microcontroller and that saves a few pennies compared to a crystal & loading caps,

Well, roger me with an award winning leek! Quartz clocks are dirt cheap and the mains frequency regulated to within a banana. A strange choice and even more unlikely than it all going pear shaped.

You learn something new every day. Ta!

[jet_noise]

Dear go,

grumbledoak said:

Well, roger me with an award winning leek! Quartz clocks are dirt cheap and the mains frequency regulated to within a banana. A strange choice and even more unlikely than it all going pear shaped.

You learn something new every day. Ta!

Step away from the blackadder fruit based simile writing tutor

regards,
Jet

[Simpo Two]

jet_noise said:

Step away from the blackadder fruit based simile writing tutor

If you put that into Google the first hit is back here.

Wibble.

[Deva Link]

HoHoHo said:

Targarama said:

Engineer1 said:

The time could be that it is taking it's "seconds" pulse from the mains frequency, 50 pulses is one second, if the power being transmitted is closer to 60hz then each second will be 5/6 of a second and so on, usually this sort of thing only happens on smaller grids.

This is what I think is happening.

Does that mean we're on a 'smaller grid' here in this part of West Sussex?

It won't be that. Old electric clocks used to do this but modern electronic things don't.

If it was frequency related, they'd be gaining more than a day a week, not 10 mins.

[HoHoHo]

Deva Link said:

HoHoHo said:

Targarama said:

Engineer1 said:

The time could be that it is taking it's "seconds" pulse from the mains frequency, 50 pulses is one second, if the power being transmitted is closer to 60hz then each second will be 5/6 of a second and so on, usually this sort of thing only happens on smaller grids.

This is what I think is happening.

Does that mean we're on a 'smaller grid' here in this part of West Sussex?

It won't be that. Old electric clocks used to do this but modern electronic things don't.

If it was frequency related, they'd be gaining more than a day a week, not 10 mins.

In my case, there seems to be no consistent gaining or loss. I have reset both clocks on so many occasions to the same time and it can then be a day, or a week or an hour and they are then different. Sometimes by minutes, sometimes by hours!

[jas xjr]

Am I the only one that does not set the time on appliances ?

[Deva Link]

jas xjr said:

Am I the only one that does not set the time on appliances ?

I set the time on some things at my Dad's house and he said 'you shouldn't have bothered, I turn them off every night'!

[jet_noise]

Dear ST,

Simpo Two said:

If you put that into Google the first hit is back here.

Wibble.

You are Dave Gorman AICMFP,

regards,
Jet

[Engineer1]

Deva Link said:

HoHoHo said:

Targarama said:

Engineer1 said:

The time could be that it is taking it's "seconds" pulse from the mains frequency, 50 pulses is one second, if the power being transmitted is closer to 60hz then each second will be 5/6 of a second and so on, usually this sort of thing only happens on smaller grids.

This is what I think is happening.

Does that mean we're on a 'smaller grid' here in this part of West Sussex?

It won't be that. Old electric clocks used to do this but modern electronic things don't.

If it was frequency related, they'd be gaining more than a day a week, not 10 mins.

Not necessarily it could be load related so during normal load it is 50hz but peaks and troughs as demand alters so it isn't a straight x many hz out. I heard something similar happened in Sicily when the connection to the mainland failed.

[grumbledoak]

It's not likely to be the mains frequency. Tolerances are extremely tight because a lot of stuff used to work that way. We wouldn't have had analogue TV for fifty years if it wasn't pretty close to spot on.

Not mentioning the content, mind. "Nice to see you..."

[bga]

OP - my Dad hasn't seen this up in Wudam.