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Random question about something not audio related
Todd Friemuth:
I have noticed recently, that the clock on both my microwave and oven have been running fast. They are on two separate circuits of a 200a panel. Everything else in my house (DVR, TV's, computers, etc) get their clocking from the internet I assume. I've noticed this since the time has changed. About once a week I have to reset the microwave and stove and back them up about 5 mins in reference to the actual time. I haven't metered the frequency yet as I don't have a meter at home that does Hz.
With all that said, is it possible that could be any indication that the transformer serving my house is about to go, or what else can the hive mind suggest I investigate that may cause this situation?
Thanks in advance.
Todd.
Andrew Broughton:
Digital clocks on the Microwave and Oven? They'll be unaffected by power other than to stop working when there isn't any.
Todd Friemuth:
Yes, both clocks are digital. They both keep exact time in reference to each other, however they both end up running about 5 minutes fast per week compared to my cell phone or the tv or anything battery operated in my house. The microwave and stove are two separate units on two separate circuits.
Jonathan Johnson:
--- Quote from: Todd Friemuth on April 02, 2018, 07:08:16 PM ---I have noticed recently, that the clock on both my microwave and oven have been running fast. They are on two separate circuits of a 200a panel. Everything else in my house (DVR, TV's, computers, etc) get their clocking from the internet I assume. I've noticed this since the time has changed. About once a week I have to reset the microwave and stove and back them up about 5 mins in reference to the actual time. I haven't metered the frequency yet as I don't have a meter at home that does Hz.
With all that said, is it possible that could be any indication that the transformer serving my house is about to go, or what else can the hive mind suggest I investigate that may cause this situation?
Thanks in advance.
Todd.
--- End quote ---
Some line-powered digital clocks do indeed get their "sync" from the 60 Hz (50 Hz in Europe) line frequency. Not all of them use an independent oscillator.
If this is the case, it seems very odd to me that they would gain or lose time, because the line frequency of the power grid is normally very very stable; it's regulated with atomic clocks. It's awfully hard to change the speed of hundreds of tons of phase-locked rotating mass.
On the other hand, I suppose it's possible that somehow you're not even connected to the larger grid, and your neighborhood is being fed by a single generating station not far from where you are. That would be a bad situation, because it's not easy to bring an out-of-phase portion of a grid back into the main grid. There again, you've got an enormous amount of rotating mass to bring into phase with the rest of the grid before you connect it, and you don't want to push the frequency too far off of target or you can damage customer equipment.
There are 10,080 minutes in a week. 5 minutes of variation in that time is about 0.05%. To gain five minutes in a week, the frequency would have to be around 60.03 Hz.
For a poor-man's frequency meter, get an analog, line-powered motorized clock with a sweep second hand. Using a quartz-regulated watch or clock with a sweep second hand, compare the two after several hours to see how much they are off and do the math.
(Good luck finding a line-powered motorized clock. They are pretty much obsolete.)
A call to your electric utility may be in order.
Tim McCulloch:
--- Quote from: Jonathan Johnson on April 02, 2018, 07:34:54 PM ---Some line-powered digital clocks do indeed get their "sync" from the 60 Hz (50 Hz in Europe) line frequency. Not all of them use an independent oscillator.
If this is the case, it seems very odd to me that they would gain or lose time, because the line frequency of the power grid is normally very very stable; it's regulated with atomic clocks. It's awfully hard to change the speed of hundreds of tons of phase-locked rotating mass.
On the other hand, I suppose it's possible that somehow you're not even connected to the larger grid, and your neighborhood is being fed by a single generating station not far from where you are. That would be a bad situation, because it's not easy to bring an out-of-phase portion of a grid back into the main grid. There again, you've got an enormous amount of rotating mass to bring into phase with the rest of the grid before you connect it, and you don't want to push the frequency too far off of target or you can damage customer equipment.
There are 10,080 minutes in a week. 5 minutes of variation in that time is about 0.05%. To gain five minutes in a week, the frequency would have to be around 60.03 Hz.
For a poor-man's frequency meter, get an analog, line-powered motorized clock with a sweep second hand. Using a quartz-regulated watch or clock with a sweep second hand, compare the two after several hours to see how much they are off and do the math.
(Good luck finding a line-powered motorized clock. They are pretty much obsolete.)
A call to your electric utility may be in order.
--- End quote ---
Or a genuine Hammond B3. Synchronous 60Hz motor. Is the organ on pitch or sharp a few cents?
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