My AC digital clocks run fast. Cheap fix?

I can't seem to get my local power company interested, but I suspect they are the cause of the problem. I've got numerous AC powered digital clocks in VCRs,
DVRs, microwave ovens and clock-radios. The appliances are all made by different manufacturers. Some were purchased this year and some are more than 10 years old. All run fast, several seconds/day. I have no problems with brownouts, flickering lights, etc. I use only typical home appliances and most of them were used in my previous homes (in other cities) where the older digital clocks that are now running fast kept almost perfect time.
Doing a little research on the web, I found an article "Solving the Fast Clock Problem" which can be viewed at this link: http://www.writenowcommunication.com/PDF_Files/Solutns/Sol03.pdf
This article leads me to believe that my problem is external to my home. I do not own an oscilloscope or any other sophisticated electrical analysis equipment and I don't want to spend the money to hire an electrical engineer to assess the quality of the power being supplied to my home. All the "power conditioners" I've explored seem quite expensive.
Some of the clocks that are running fast are plugged into surge strips that have EMI/RFI suppression built-in, so I doubt that an additonal EMI/RFI filter would solve my problem.
Is there a simple, inexpensive solution to my problem or am I condemned to resetting about 7 digital clocks each week if I want my wake up when I want to and record TV programs when they are broadcast rather than before they start and miss the endings?
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Although it is easy to blame the power company, I would have to say it is not their fault or problem. The business of the power company is just that, to supply you with power. Nothing within providing that service indicates they're responsible to provide a clock timing pulse. This business of clocks being accurate falls back to the manufactures. It's up to them to make a product that works correctly. Instead of building an accurate clock, they've taken the cheaper shortcut of trying to use the 60 Hz power line as the timing circuit.
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wrote:

There are requirements for long-term (30-day) accuracy.
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Here, in Crete, south Greece, the local control centre of the utility (www.dei.gr) has a special display on the control room, that tells how accurate a 50 Hz clock would be, had it followed the mains frequency. So. yes, utilities care for those clocks, at least in Greece.
--
Tzortzakakis Dimitrios
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Tzortzakakis Dimitrios wrote:

Here in the US I've visited a regional system operator and they have a very similar 'clock' for 60 HZ. I would assume all sysops in the US have this concern as well.
daestrom
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daestrom wrote:

It is easy to see how a single power plant can change the frequency for an isolated system.
How does a "regional system operator" make fine adjustments in the frequency of an interconnected grid?
--
bud--

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bud-- wrote:

Well, the simple answer is, "By raising/lowering the speed of the connected generators." :-)
The more complicated answer has to do with many generators are running as base-load where the governor is *not* the item controlling steam/power flow into the generator. And a few generating units *are* running as 'regulating units', where power flow into the generator is a function of the generator's speed.
To raise the system frequency, the sysop can call a *non-regulating* and has them pick up more load. This slowly raises the system speed and as speed rises the regulating plants shed some load as they speed up. If the regulating units are adjusted well, they will all shed load in similar percentages. The result is the base-load unit is carrying more load and the grid frequency is now maintained at a higher level by the less-loaded regulating units.
You can get the same effect by raising the governor setting of one or more regulating unit. But raising the setting on only a few regulating units causes them to pick up load away from other regulating units. So naturally you call them and ask them to speed up a bit. So 'adjusting' all the regulating units can take a while.
Which way you choose to go depends on how well the various regulating units are balanced and how evenly loaded your base-units are and other factors (hydro have complex water policies).
At least that's how it used to be done. Now with deregulation you have to also consider all sorts of price schemes where one base unit might be obligated at one price while another is contracted to deliver a certain amount of power corresponding to a particular customer agreement.
Also, nowadays computer programs also keep track of various contract $$ and unit limits and distribution line limits. A pretty fair amount of prediction of what load will be needed hour-by-hour and more. Many regulating units now can be controlled over at least part of their load range from the sysop using SCADA computer systems. Of course as with any computer, GIGO (garbage-in, garbage-out).
daestrom
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Here, they have the base-load plants running 24/7 anyway (Crete, south Greece, isolated small grid), basically two-stroke diesels and small steam turbines, fired with mazut.), and they have the servers that control the grid control a regulating unit (usually a gas turbine, fired with ordinary diesel) controlling its output so that it picks/sheds load. There are UF (Under Frequency) relays on select medium-voltage (15 kV) circuit breakers that shed those loads, when the grid's frequency goes below a chosen point (automatic trip of those breakers). The best fuel economy have the two-stroke diesels, with 100 grams of mazut for each kWh IIRC, and then the steam-turbines, with 300 gram/kWh of mazut. The worst are the gas-turbines, with their expensive fuel, and are used only in peaks. There are no hydro in Crete.
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Tzortzakakis Dimitrios
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Tzortzakakis Dimitrios wrote:

So you only have one or two units acting as regulating units? Then it certainly would be easy to keep them set the same as you adjust up/down. When you have many more units working 'regulation', it's often easier to raise/lower a non-regulating unit. That way the settings of all the regulating units don't have to be adjusted together constantly throughout the day.
Some non-regulating units are not operated at full load all the time like a base-load plant. Instead they would come on line and carry an amount of load dictated by system operator. As system load rises, at first the regulators would take it but that resulted in system frequency dropping as the regulating units are loaded down. Then the sysop would call one of these non-regulating unit and ask them to pick up more load. When they did so, it took load away from the regulating units and system frequency rose back again. Since the regulating units didn't have to change their settings, they all gain/shed load simultaneously. You adjust one or two plant's output and all the regulating units can be left alone (well, most of the time anyway).

We have load shedding too, but that's considered a bit drastic. In the days before deregulation, we too would consider heat rate and fuel costs (combined into simply marginal cost for any given unit). When you owned all different forms of generation and were responsible to a regulator to act prudently, you would operate your mix of plants to get the lowest overall cost.
With deregulation it's up to each generating company to bid a price they can afford sell at and that will still win them some bids. But in times of high demand, price isn't set solely by what it costs the generator to create the power. If a generator is pretty sure his power is needed, he can bid a higher price and still win. In times of low demand, plants with high fuel costs end up bidding a price that doesn't win so they don't put onto the grid.
daestrom
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Peter wrote:

The line frequency should have excellent long term accuracy. It may drift a bit during the day but should catch up at night. If you're in the US, I don't see how the frequency could be off since it's one big interconnected grid. You might have noise on the line causing this. Can you tell if the clocks drift steadily and in sync with one another or do they sporadically skip?
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James Sweet wrote:

They drift steadily. I haven't actually taken the time to precisely measure the amount of drift that each clock has, but after a week, each is about 9-12 seconds fast. (My calibration standard is the time on both my "atomic" desk clock and wrist watch, which are never more than an infinitesimal amount different from each other.) It's a real pain for my VCRs and DVRs when we are out of town for several weeks. Inevitably we end up missing the end of programs we recorded near the end of our absence. Lately I've been adding 1-2 minutes to the turn-off time to avoid that.
From the responses so far, sounds as though I'm going to have to live with this issue until I move. I'll check with some of my neighbors to see if they have noticed the same problem. However, I suspect from the random pattern with which they collect their newspapers off their lawns that they may be less compulsive than I am and not even be aware of the problem if they have it. If they have cable or FIOS TV service (I don't bother) their VCRs and DVRs probably remain accurate from the time signal I believe is transmitted with those services. (My VCR was accurate until the analog to digital transition.)
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Peter wrote:

Actually it's a couple of 'big connected grid's, but your point is valid. US frequency, in the long term, is very accurate.

Don't know if this is related, but I've noticed some networks do not have shows start/stop exactly on the hour/half-hour anymore. Sometimes a show runs 'long'. I've actually seen a couple of episodes claim to run from 8:00 PM to 9:02 PM.
Go figure. I remember when you could almost set your clock by when the first commercial break would come in. Remember 'Wild Wild West'? It was originally four commercial breaks and they would put a still image in each quadrant of the screen for each segment. Nowadays a show would go under with so little commercial space.
daestrom
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wrote:

Star Trek, TOS, were ALL 50 minute long episodes.
That only allows for four 2.5 minute long breaks.
Nowadays, they go to commercial before 6 minutes have passed, and some of the "breaks" last through 6 commercials!
They also often start with "Previously on..." So they can waste away four more minutes of new storyless content.
It really is pathetic that they can make such good shows, but nip away at the actual airtime they give to us. It is truly sad.
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wrote:

Get a cheap electric clock that runs on a synchronous motor. See if when it uses the power line frequency, which all these cheap clocks do, if they have long term inaccuracy. Even quartz crystal clocks can be off. Most new VCR synchronize off of PBS YV statops.
Bill
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As the years go by, dying just before having to fill out a tax return has merit.

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My stove's clock is an old fashioned synchronous motor clock. It keeps good time. I suspect the problem is noise spikes, and probably not frequency inaccuracy.
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wrote:

If that is the case, you need line filtering. A surge protector might do it. Use the equivalent of what is used to keep rf out of screen rooms. A screen room filter costs too much but you could assemble something good enough much cheaper.
Bill
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As the years go by, dying just before having to fill out a tax return has merit.

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Surge protectors (eg. MOVs) do not clamp spikes that are at or below the mains voltage, yet these spikes can still play havoc with the mains frequency detector in clocks. EMI filters (L's and C's in a box) will do a better job. You may need a strong one!
G.
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On Mon, 16 Nov 2009 14:29:47 -0800 (PST), glenbadd

AC synchronous clocks do not have any such "detector".
The frequency IS what determines their operating speed.
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On Mon, 16 Nov 2009 17:50:04 -0800, Capt. Cave Man

Wrong again, WrongAgain.

And spikes at the crossings *can* fool them, DimBulb.
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The only moving part is the rotor. The other "work" part is the coil. There are NO electronics.
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