I need to build a board with 7-segment LED clock (hh/mm/ss) it is very important to have seconds and power suplay is 12V in car
Does anyone have a circuit for this?
Thanks!
- posted
18 years ago
LED clock?
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- posted
18 years ago
A clock is a bad project as it will never be sufficiently accurate.
Rene
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- posted
18 years ago
Guaranteed accuracy of a couple minutes a year should be achievable using an off-the-shelf TCXO. Doing firmware compensation on a
32.768kHz oscillator would be more fun, though.Best regards, Spehro Pefhany
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- posted
18 years ago
Not accurate enough for what?
For the OP, try Googling on 'led clock circuit', or just cruise over to:
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Cheers.
Ken
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- posted
18 years ago
Whoops, meant to mention - use the 12V supply instead of the transformer and IIRC (without checking....) there's a clock circuit for 50 or 60 Hz on that site as well.
Ken
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- posted
18 years ago
The availability of the 50Hz signal may be an issue in a car.
Best regards, Spehro Pefhany
-- "it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
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- posted
18 years ago
As clock. The only clock I can trust to have accurate time is my battery operated radiocontrolled one. Every other, be in the car or wherever is suddenly off by a minute or so and the railway or the bus is gone.
Rene
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- posted
18 years ago
I need to adjust time!
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- posted
18 years ago
And that should worry the OP (or anyone else) for what reason? Oddly enough, clocks other than your one special battery powered, 'radiocontrolled' one have worked just Jim-Dandy for a few years now.
'Suddenly' off by a minute sounds like operator error. Buses and trains running on time sounds like Nirvana. Or Elton John on a good day.
Ken