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Long delay Timer

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raindeepak4u

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Hi all,

Please any one give me link to getting long delay timer circuits . I am planning to make a custom timer for my aquarium with out the use of micro controllers for that i need a timer circuits . please any one of you provide some circuit sources.thanks in advance.



Regards
Deepak
India.
 
Here is a link for a 120Vac timer that can be set for 1,2,4,or 8 hours.

**broken link removed**

What control voltage do you need
 
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If it's an 8hr mains timer it would be safer and cheaper just to buy a standard wall timer as suggested. Else a crystal and CD4060 plus a bunch of dividers & relay. Then you'll have to figure out how to handle the off time (as you didn't specify)
 
blue off the timer and all r not problem am using it for day time purpose only so i can use LDR to control it or off it...
 
What we have here is a failure to communicate.

Deepak, If you can, please explain what it is you are trying to do.

How long you need the timer On and OFF is a start
Next, please try to tell us what you are going to want to do once the time has elapsed
 
So it needs to run once every 8hrs or once every 24hrs? Either way looks like a handful of ICs, I would start by looking at the previously suggested CD4060 and a 32768Hz watch crystal.
 
the problem is in my planted tank i need a lighting for 8 to 10 hours for my plants for that i am planning to do a project to build a custom timer with out using controllers for that i need a timer circuit which on the lights for 8 to 10 hours and then goes off. the initial trigger is given by alarm table clock.

make working it into 24 hours is not problem . they long delay is problem not yet getting any circuits from 1 hour googling.
 
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You're building more than one? Then use a micro, a simple 8pin like the 12F508 would have no problem with such a task. If it's AC powered then you can clock it using the mains frequency which is pretty accurate.
 
**broken link removed**
**broken link removed**
EDIT:
The above schematic contains an error: C3 should be non-polarised (see text on schematic and on the site the link takes you to).
 
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Heres another I'm working on.. Generally the same as above, but uses additional counters to control on/off periods rather than an rc time..
Basically the counters IC6 & IC7 only count once then reset the counters IC4 & IC5, to properly sync/(or rather unsync) them.. IC4 & IC5 each reset and flip the relay once/daywhen they hit their count.. One of those turns the relay on once/day, and the other turns it off once/day.. A day is however many minutes the counters IC4 & IC5 are set to count.. Both these timers should be set the same.. The number of minutes between plugin, and flip on time are jumpered to the IC6 counter, and the number of minutes from plugin to flip off time is jumpered to the IC7 counter..
So it gets plugged in, all counters start, when IC6 counter hits its total it resets the IC4 counter to zero and turns on the relay.. IC6's job is now complete until the unit gets unplugged because IC4 flips the relay on everytime it resets and begins another day..
Same thing happens with the IC7 & IC5 pair of counters to turn off the relay..
So lets say you wanted a pump to come on for 10min each hour, but you don't want it to come on the first time until 15 minutes have passed..
The 2 diode/jumper banks from IC4 & IC5 are each set to 60..
The IC6 jumper bank gets set to 15
The IC7 bank gets set to 25 (15minute wait+10min duty)
And the process repeats every hour..

A day can be anything from 2-4096 minutes (24hr=1440min)
On/Off periods can be 1-4094min logically..
Minimum 2min is because IC6 & IC7 cannot be allowed to reset simultaneously, so do not set them for the same number of minutes..

The board can obviously be simplified by specializing it to your timing needs instead of making each of those banks fully adjustable from 0-4096 minutes..
BTW, on the right side via IC1 & IC2, the crystal is divided to create a 2Hz clock, which is further divided by 120 to create a 1minute count for easy time management..

I'm also including a simpler version that needs to be manually told when to trigger on the first day period, then repeats the routine after that.. In that circuit, those ugly black marks by pins 4 & 6 of IC3 are normally closed pushbuttons that need to be pressed at the appropriate time on the first day to force reset and sync the IC4 startup counter, and the IC5 shutdown counter.. All circuitry added in the larger scematic is to electronically perform that function thus eliminating the need to be there at appropriate times on the first day..
 

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BTW, those wierd black lines/dots on the lines in the right pic are normally closed push buttons.. In that circuit you need to wait until desired on/off time and then press the respective button to reset that timer on the first day.. The additions to the left in the other circuit basically replace the need for those buttons..
It just occurred to me I forgot to draw in the 9V battery between the power and ground rails.. Its not actually necessary, but without it, the timing will get all out of synce if the power goes out.. The battery lets it keep counting..
 
The right schematic is probably the best one in this thread because it uses a crystal oscillator which is very accurate.

I would recommend the single 4060 circuit over the left schematic because it's just as accurate and much simpler.
 
The right circuit is the basis for the left.. With a crystal and a single 4060 you could only count to 1s.. In both circuits, the 4060 and 4040 on the right formulate merely 1 minute periods.. those are counted by the two in the center (and the 2 on the left) to a maximum of 4096min (this period whatever its jumpered to constitutes a day).. The simpler circuit has a major disadvantage of needing to wait around to tell it when to on/off on the first day with the buttons.. everything to the left just lets you set and forget..
 
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