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nclay
Joined: 17 Mar 2007
Posts: 1
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 Posted:
Sat Mar 17, 2007 5:43 pm Post subject:
timing circuits, questions! |
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Im trying to make a circuit that has multiple timers in it, about 5, what i want it to do is have a red and green light for each timer, when the timer is active then the green led is active, if the timer is not active then the red led is active.
Im not new to the the traditional 555 based timing circuits and such. But in the case i need a user selectable range of 1-30 days.
Suggestions, tips, or point me in the right direction, and it will be greatly appreciated.
-Nick
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when in doubt look for sub-delta |
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Retiredguy
Joined: 13 Nov 2006
Posts: 8
Location: Kent, OH
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Mon Mar 19, 2007 3:28 pm Post subject:
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Nick,
If what I think you want to do is to have these timers to turn on and off LED's after a certian amount of time, then a microcontroler would be your best bet. However, if you are not versed in these, as I am not, you could use a stable time base and counters to set up the amount of time you would wish to pass before the LED's would change. If you can get your hands on a CMOS LOGIC DATA BOOK by Motorola, under the MC4040B, there are some examples on how to do this. Hope this helps some.
Mike
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Retired Guy |
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razorreilly09
Joined: 07 May 2007
Posts: 4
Location: US
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Thu May 17, 2007 10:16 am Post subject:
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Nick, as previous mentioned, you can purchase standard microcontrollers for general use; 120vac, 20-30amps with 2 sets of opposite contacts for around $150 , they are usually 7 day continous timers and have battery memory. I purchase them from Grainger all the time and use them for irrigation and motor controllers-goodluck, Jeff
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neon
Joined: 25 Feb 2006
Posts: 593
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Fri Jun 01, 2007 1:52 pm Post subject:
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| well if you read the specs on LM 555 and mostly capacitors you will relize that is a 30 days wet dream. the inpossible to inplement 30 days caps leaks and to discharge the monster the LM555 cannot do it. one day ok |
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