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Countdown Timer Answered

Hey guys, first forum post.
I have just gotten into the electronics field, and I have made a few circuits that I have read schematics from. There's something I want to make, and it's a countdown timer.
This is want I want it to have:

Be able to count down from at least 15 seconds and be able to change the amount of time
Have some 7 segment displays
Use the least amount of voltage possible (ie: not need to use the mains or some 12 volt power supply, id rather use a couple of AA's)
Have a relay capable of turning on or off a light.
And to be as simple as possible.

Because I am rather new to this I would rather a schematic, rather than just some help on which components I need to use, because I don't know where they need to solder to where. 


6 Replies

ryanlg (author)2010-10-26

I do have an arduino, but i am hopeless at coding. and telling me components I could use is no use to me, I wouldn't mind schematics.

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Goodhart (author)2010-10-25

Other then Kiteman's suggestion (probably the easiest if more expensive way to go), there are other TTL and CMOS ICs that will do the job, but you need to have supporting passive components like resistors and capacitors, and of course the Spec Sheet for the IC helps a LOT.

If you still are having difficulties configuring the IC of choice, try a search here, and then if nothing shows, try Google. There are a lot of ways to do this.

Your last statment: to be as simple as possible
pretty much leaves out one or two countdown IC's, a display driver and lots of passive parts, and the Arduino looks like the best bet.

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Kiteman (author)2010-10-25

Have you looked into PICaxe or Arduino?

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Kiteman (author)Kiteman2010-10-25