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I still haven't figured out what time has been "saved" by the three minute time zone between the bathroom & the rest of the house, but I guess it works for them |
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This is more being too dumb to figure out how to change it without the manual, being too lazy to find the manual, getting used to the unacceptable, then during time changes relying on me to fix the hour then wanting to keep the minutes wrong....on one clock and 2-3 minutes off it's not the end of the world, but when it's 4 or more clocks each off by different larger amounts for no meaningful/real reason it starts to get excessively difficult to manage and confusing. On the car clocks I generally cut the drift in half and try to set it by that amount in the opposite of the drift so for the half of the year between adjustments it's at least closer to correct on average than it otherwise would be.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
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Years ago I had one of these mains-based clock... sometimes it become crazy and doubled the seconds count (it blinked at 1/2 second interval) for a minute or so...
In fact, mais based clock is in reality a pity, since in the reality, the mean frequency in practice is slight > 60Hz (or 50 for the 50Hz countries) in the long run, even with national operators dictating near 60Hz for entire interconnected system (for example, here in Brazil) and power plants need to sync with it perfectly or they are automatically disconnected (of course, due to electrical phasing mismatch/overload etc). Here also is common to a mains based clock to having 1 to 4 minutes/month added. I have a DIY clock with 6dB passive plus 24dB/oct active filtered clock followed a carefully calibrated squarer to pick the mais freq, and even so, this time difference occurs. I also have a crystal clock in the car that advanced 5 minutes in a month... when I have some time I will sub the internal circuit for one from these home wall clocks that have far more accuracy. Recently I built this vector CRT clock: http://www.sgitheach.org.uk/scope2.html having a promising RTC; will be very happy if the RTC is precise as described in it's datasheet (about the time issue)...
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So many projects, so little time... |
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Here are some actual measurements from a place in the Netherlands: https://wwwhome.ewi.utwente.nl/~ptde...20using%20them. However, the freedom from transients, dropped cycles, etc., has not necessarily improved over time. |
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Too many coincidences with too many observations led me to believe that (along with some other technicians frinds of mine), even after talking with a colleague that is from a sector near the operators here in the Itaipu DAM (where I work, but at other sector not related to this). He is not a authority in this subject, but he explained at that time the same explanation in this page you mention here, that the ONS here (National Electric System Operator; Operador Nacional do Sistema Elétrico in Brazilian Portuguese) enforces exactly mean 60Hz in long run, but I didn'd see a graph for the long run, and I wondered if in a month the national grid deviated slight above 60Hz mean. In short run, frequency is subject to some variations due to various demands. And I talked with him about this same subject of clocks at that time, but he believe that all clocks being bad filtered etc. Perhaps I need to ask to an actual operator about this subject. Of course, is not possible to cathegorize my clock being ultra scientific accurate (more professional measuring is needed). And, of course, most other ones have paltry filtering. That's correct, is a belief, to be yet checked with some more professional work (or to find one already made); maybe the more correct sentence here is: "I strongly believe that in practice this"...
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So many projects, so little time... |
Audiokarma |
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