Archived from groups: rec.audio.tech (
More info?)
"Karl Uppiano" <karl.uppiano@verizon.net> wrote in
news:Z5axd.263$L7.255@trnddc05:
>
> "Barry Mann" <zzzz@zzzz.zzz> wrote in message
> news:41c51860$1$avgroveq$mr2ice@wcnews.cyberonic.com...
>> In <cpuqod$iol$1@news.ks.uiuc.edu>, on 12/17/04
>> at 08:33 AM, "Chad Wahls" <cwahls@uiuc.edu> said:
>>
>>
>>>"Richard Crowley" <rcrowley7@xprt.net> wrote in message
>>>news:10s4psjjfjroq27@corp.supernews.com...
>>>> "ansermetniac" wrote ...
>>>>> I want to use a CD player from Europe. Do I need the frequency
>>>>> conversion. I prefer the cd to spin at the proper speed
>>>>
>>>> Almost NO electronic equipment any more cares what the power/
>>>> mains frequency is. Certainly no CD players do (or ever did).
>>>>
>>
>>>Alarm clocks, even digital. Use mains freq.
>>
>> Yes, ,many electronic clocks count cycles, but they have an internal
>> clock that is accurate enough to determine if it is plugged into 50
>> or 60Hz and the cycle counting is adjusted accordingly. In industrial
>> nations with smooth running power grids, cycle counting results in
>> very accurate time keeping. Hour by hour a few cycles may slip, but
>> the power grid will make up for it later. As a result, the long term
>> accuracy is very good. In remote, off grid, or under developed areas,
>> power frequency control is not as good and clocks with accurate
>> internal time bases are more reliable.
>
> That's true for time-keeping, but most microprocessor-controlled
> devices such as CD players, simply use an internal quartz crystal
> timebase not tied to the line frequency. They might not be extremely
> accurate, but they are very reproducible, and certainly more than
> accurate enough for the application at hand.
>
>> You may be aware of how poor most personal computers are at time
>> keeping. Slipping a minute or two (or more) per month is about par.
>> (yes, some are more accurate, but it's a happy accident, most are
>> not) These clocks are usually crystal controled. In my experience (in
>> the US) a simple motor driven or electronic cycle counting clock
>> (assuming no outright power failures) is rarely off by more than a
>> second or two over a period of months.
>
> Many computers can automatically sync up with Internet time servers,
> so they are generally very accurate these days, even if they only
> connect infrequently.
If your computer doesn't already have software to do this, NISTIME is a
good application to acquire. It's available at a number of sites, a couple
of which are given below:
http
/www.boulder.nist.gov/timefreq/service/its.htm
http
/www.pcworld.com/downloads/file_description/0,fid,23895,00.asp
It can be run manually. If you have cable or DSL you can configure your
registry to run it at startup (a registry setup file is available at the
pcworld site), or you can add a startup link to it.
I've been using it for a couple of years now with no problems. One of my
PCs has the clock from hell. Loses about 30 seconds a day (and, no, its
not the battery).
>
>> Any more, inexpensive appliances must operate anywhere in the world.
>> It is much too expensive to have a fresh design for each region.
>> There are relatively minor differences to satisfy unique regulatory
>> requirements of different regions. For example, a unit that is
>> considered "legally safe" in the US, may not be "safe" in Europe.
>> Multi-voltage units that are "safe" in Europe, are not "safe" in the
>> US. Power cords vary with the map. That's why so many products come
>> with an external power supply and a multi-language instruction
>> manual. Except for some minor variations in language printed on the
>> controls and setting an internal switch for the display language, all
>> the units are identical and can be assembled in massive quantities of
>> identical units -- there's no need to slow down to customize for each
>> country. It's a simple matter to drop an appropriate power supply
>> into the box before it is sealed.
>
> Another reason manufacturers like to use wall-wart power supplies.
> That was being debated on another thread in this NG.
>
>
Please don't go _there_ again!
-- JS
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