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Real time clock basics

J

Jack// ani

Jan 1, 1970
0
Hi all,

How do those RTC work...do they need external battery backup or
something else to maintain time??

Thanks
 
D

Dan Hollands

Jan 1, 1970
0
Jack// ani said:
Hi all,

How do those RTC work...do they need external battery backup or
something else to maintain time??

Thanks

Some have internal batteries and some require external batteries

Sometimes a very large value capacitor is used in place of external
batteries

Dan

--
Dan Hollands
1120 S Creek Dr
Webster NY 14580
585-872-2606
[email protected]
www.QuickScoreRace.com
 
J

Jack// ani

Jan 1, 1970
0
Hi Dan,

Thanks for reply...do internal battery need charging, how long do they
last??

Thanks
 
R

Rich Grise, but drunk

Jan 1, 1970
0
Hi Dan,

Thanks for reply...do internal battery need charging, how long do they
last??

Thanks

You'll have better luck with a question like this if you actually use the
other side of google - the web search.

Try various things in the search box, like "Real Time Clock Batteries" or
whatever search phrase you want to make up - you will be amazed at what's
already out there.

Admittedly, that's a lot colder and less fun than interacting with actual
real live people, but huff! This is the sci.electronics.design group, not
the sci.electronics.basics group, so we're all insufferable arrogant prigs
who mercilessly flame anyone who asks an impertinent question.
<pause for audience laughter>
Was everybody able to discern that that was a joke? ;-)

But in answer to your question, the only honest answer is, as usual, "It
Depends." :)

Good Luck!
Rich
 
J

Jack// ani

Jan 1, 1970
0
Hi Rich,

If you can read properly.....the thread is posted in
*sci.electronics.basics* not sci.electronics.design!!!! Dosen't that
makes any difference....and turns what all you said useless!!!!!
 
J

Jasen Betts

Jan 1, 1970
0
Hi all,

How do those RTC work...do they need external battery backup or
something else to maintain time??

yes.

some are encapsulated with the battery,

other use an seternal battery. these days a 3v lithium disc cell or a large
capacitor is commonly used,

In the past on-board NiCd rechargables and external battery packs been used
as well.

Amstrad even made a computer with an external battery compartment.

Bye.
Jasen
 
J

Jasen Betts

Jan 1, 1970
0
Hi Dan,

Thanks for reply...do internal battery need charging, how long do they
last??

no, when the battery fails the unit must be replaced (or opened and the
battery replced)

about 5 years.

the first signs of a failing battery is that the PC's real time clock starts
losing time and then stops

As the clock chip also stores the BIOS configuration info the next sign is
corrupted config info.

Bye.
Jasen
 
R

Rich Grise

Jan 1, 1970
0
Hi Rich,

If you can read properly.....the thread is posted in
*sci.electronics.basics* not sci.electronics.design!!!! Dosen't that
makes any difference....and turns what all you said useless!!!!!

Sorry, I won't bother you with any replies next time.

Good Luck!
Rich
 
M

Mr. C

Jan 1, 1970
0
Some have internal batteries and some require external batteries
Sometimes a very large value capacitor is used in place of external
batteries

We are now using a 1 Farad super capacitor with our RTC. If you do
not expect long power outages (like several weeks), the super cap is a
nice way to go. It does not require replacement like a battery and
can be permanently installed.

On the other hand, if there are few power outages, a lithium battery
would also work well since it has such a long shelf life. The
supercap/RTC combination we use retains the time for outages well over
one month.

Lou
 
J

Jack// ani

Jan 1, 1970
0
Hey Rich......I've no such intention, so keep posting!!
 
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