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| Thread ID: 139381 | 2015-04-24 05:18:00 | My Digital Clock Gains Time... | Ruralkiwichik (17361) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1399211 | 2015-04-24 05:18:00 | Hi there... I found a post from 2005 from Beemer in Horowhenua, who's digital clock was gaining time... Is there any electrician out there that knows what to do about this that lives in or near Levin?? | Ruralkiwichik (17361) | ||
| 1399212 | 2015-04-24 05:43:00 | I have noticed on 3 different clocks that use a 9V battery as a backup that they gain time when running on the battery. Had any power cuts lately? My alarm clock is hiding in a corner still on daylight savings time, I never look at it any more instead I just use my phone. |
dugimodo (138) | ||
| 1399213 | 2015-04-24 06:02:00 | .. you might be wondering why a quartz watch doesn't keep time with absolutely accuracy forever. The answer is that the quartz vibrates at a slightly different frequency at different temperatures and pressures so its timekeeping ability is affected to a tiny degree by the warming, cooling, ever-changing world around us. In theory, if you keep a watch on your wrist all the time (which is at more or less constant temperature), it will keep time better than if you take it on and off (causing quite a dramatic temperature change each time). But even if the quartz crystal could vibrate at a perfectly constant frequency, the way it's mounted in its circuit, tiny imperfections in the gearing, friction, and so on can also introduce minute errors in timekeeping. All these effects are enough to introduce an inaccuracy of up to a second a day in typical quartz clocks and watches (bear in mind that a second lost one day may be compensated by a second gained the next day, so the overall accuracy may be as good as a few seconds a month). The average quartz watch has a variance of 0.5-2 seconds per day. The average mechanical or automatic watch has a variance of 3-5 seconds per day. ...and my really old non-quartz clocks keep awful time, loses a few MINUTES a day....LOL. |
pctek (84) | ||
| 1399214 | 2015-04-24 06:28:00 | I bought an old mains Technica LED bedside clock/radio to put under our TV. Darn thing gains about a min per day. Darn nuisance! Don't know what it uses to synch with. | linw (53) | ||
| 1399215 | 2015-04-24 06:46:00 | Hi there... I found a post from 2005 from Beemer in Horowhenua, who's digital clock was gaining time... Is there any electrician out there that knows what to do about this that lives in or near Levin?? Most electricians would not know what to do :banana........... with apologies to any electricians out there who do know. It's more of an electronic job. Most quartz oscillators have a tiny tiny trimmer to adjust the frequency a minute amount, similar to adjusting the balance wheel spring on a mechanical watch. It can take a long time to adjust to get best time keeping, say a week of checking and careful tweaking. Use internet time to set the clock. Use the local time server msltime1.irl.cri.nz. Otherwise, just use internet time to determine the clock's rate, ie the amount it gains or loses and then apply a correction. |
Terry Porritt (14) | ||
| 1399216 | 2015-04-24 07:46:00 | Wow, I have got a Seiko Kinetic watch which replaced my 12 yr old old Seiko Kinetic. (Son now has the old one.) SWMBO gave me the new one for my 70th birthday over 2 years ago. I wear my watch all the time and what pctek says about that sounds true. I only have had to adjust both watches in their time, twice a year, at daylight saving time. Neither of them have been any more than 10 seconds out. I can highly recommend them. Ken |
kenj (9738) | ||
| 1399217 | 2015-04-24 07:52:00 | Battery backed mains powered digital clocks are synchronised to the mains 50hz - this (the 50 hz) is not startlingly accurate in the short term (minutes) but very accurate indeed over a period of hours or days. (Power cuts excepted.) However, the National Semiconductor integrated circuit they almost all use to control the clock functions plus drive the display is usually set with the battery timekeeping controlled by a simple RC circuit that is intended only to be "near enough" for brief power outages. They allowed an option for 50 or 60 hz to be selected by the clock manufacturer to suit the mains frequency of the country of sale. What they neglected to do was provide any option for the battery time frequency generator to conform. Naturally, the battery frequency is set for "Them", so for us we have a 50 hz clock gleefully counting down from a 60 hz reference while the power outage lasts. This means during power cuts the clock runs 20% too fast. A possible solution is to migrate West during power cuts to take advantage of the time zones, but often the power cuts are too short to give you a full hour of gain, and frequently you are going to be in a pretty wet location which introduces other problems, aside from the commuting hassles. Plan B might be to use time dilation at extreme velocities, this poses the obvious risk of trying to run at close to the speed of light at night in a power cut. (If it's not night, why do you care what time your bedside clock shows?) The wimp's solution is to use the wee buttons on the clock to warp time to suit your needs, but beware weekend power cuts that might slam you right into a Monday and miss Sunday altogether. Naturally, observe all safety precautions shown in the clock's approved manual of procedures. Correct protective safety apparel should be warn while carrying out temporal rectification, and all applicable by-laws and ordinances must be strictly adhered to. Clocks used for timesaving purposes may be required to display a certificate of compliance with Ministry of Time standards. ;) |
R2x1 (4628) | ||
| 1399218 | 2015-04-24 08:04:00 | My Seiko brand battery-powered wristwatch, which is now 34 years old, still only loses about 7 seconds per month. It's been a brilliant gadget, despite my seldom wearing it. And the cool thing is that the batteries have given me between seven and nine years between changes. | Greg (193) | ||
| 1399219 | 2015-04-24 10:36:00 | I have a bed-side digital alarm clock that runs on mains power and it gains time. It's currently about 3 mins faster than the correct time. When we have power cuts I have to add the time in again and reset all the preset radio stations, so the theory about the battery back up doesn't apply to mine as it doesn't have any. I'd like to know why it does this too. On the hand hand my kitchen clock, which is a battery powered clock with hands rather than numbers (whatever you call them - too tired to think of the word right now), constantly loses time. It's a cheap and nasty clock but the actual thing the clock is set into is rather cool and I like it as an ornament, hence not chucking it away. I just have to remember to move the clock forward a few minutes every week or two. :) If I want to know the exact time rather than the rough time I look at my phone or laptop. |
catspyjamas (15614) | ||
| 1399220 | 2015-04-28 00:54:00 | we haven't had any power cuts at all as I know it gains then, but this was just plugging in and letting it go... the gain is about an hour... also I don't know whether this has anything to do with it but my partners tablet was working okay before we moved in and he was charging it on the same power point as we plugged the clock into and the tablet doesn't work anymore... the house was built in the 1920-1930 era so not too sure if it has anything to do with that either :o) I hate being an electro-dunce :o)) | Ruralkiwichik (17361) | ||
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