Need timer circuit by NE555

[phongphanp]

I want to setting for water to tree every 6 hour twice per day except the midnight.
And for situation when hot temperature , I plan to use RTD for default , can we get all in one circuit ?

Thanks up,
Phongphan Porana.

 

[kam1787]

555 is not so good at timing for long intervals.

you might look at:
http://www.brighthubengineering.com...-simple-versatile-long-duration-timer/#imgn_0
http://www.electroschematics.com/8749/0-3-seconds-to-10-hours-timer-relay/
**broken link removed**
**broken link removed**
http://www.reuk.co.uk/Timer-Circuits-With-4060B.htm
http://www.zen22142.zen.co.uk/ronj/rts.html

You can 'OR' the output of the timer and the RTD to turn on the water.
http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/trangate.html
http://www.circuitlab.com/circuit/9dg8h8/bjt-or-logic/

BTW you can NOT "every 6 hour twice per day except the midnight" with the usual timer. Besides, every 6 hours [excepting midnight] would be 3 times a day. With the usual timer, it is every Nth interval - no exceptions. You could use a wall timer **broken link removed**

 

[yassin.kraouch]

555 is not so good at timing for long intervals.

you might look at:
http://www.brighthubengineering.com...-simple-versatile-long-duration-timer/#imgn_0
http://www.electroschematics.com/8749/0-3-seconds-to-10-hours-timer-relay/
**broken link removed**
**broken link removed**
http://www.reuk.co.uk/Timer-Circuits-With-4060B.htm
http://www.zen22142.zen.co.uk/ronj/rts.html

You can 'OR' the output of the timer and the RTD to turn on the water.
http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/trangate.html
http://www.circuitlab.com/circuit/9dg8h8/bjt-or-logic/

BTW you can NOT "every 6 hour twice per day except the midnight" with the usual timer. Besides, every 6 hours [excepting midnight] would be 3 times a day. With the usual timer, it is every Nth interval - no exceptions. You could use a wall timer **broken link removed**

do we have IC which can give long delay time, and also retriggebale ?
many thanks,

 

[phongphanp]

What's long your interval , I think the NE555 can take more than 10 years for working mode. That's not enough !

 

[yassin.kraouch]

no i mean retriggebale but i need just 3 minutes

 

[BradtheRad]

A counter IC is a convenient way to divide down the pulses from a 555 IC.

Example, 4020, 4060, etc.

These consist of a train of divide-by-2 flip flops.

It would be tedious to try to obtain a 6-hour interval directly. You would have to sit and watch for hours after you make an adjustment.

It's easier if you adjust the 555 to put out a pulse every 21.1 seconds, then divide the pulses by 1,024. That way you know you have a 6 hour time interval.

Here's my idea to prevent the water from operating in the middle of the night... A photodetector.

However if you do not use a photodetector, then you must count 3 times to go 'ON' and 1 time to stay 'OFF'. This adds more circuitry to the project.

 

[yassin.kraouch]

A counter IC is a convenient way to divide down the pulses from a 555 IC.

Example, 4020, 4060, etc.

These consist of a train of divide-by-2 flip flops.

It would be tedious to try to obtain a 6-hour interval directly. You would have to sit and watch for hours after you make an adjustment.

It's easier if you adjust the 555 to put out a pulse every 21.1 seconds, then divide the pulses by 1,024. That way you know you have a 6 hour time interval.

Here's my idea to prevent the water from operating in the middle of the night... A photodetector.

However if you do not use a photodetector, then you must count 3 times to go 'ON' and 1 time to stay 'OFF'. This adds more circuitry to the project.

have you an ieda if therer is retriggebale timer with a delay more than 150 second ?

 

[schmitt trigger]

There is a CMOS timing circuit (CD4045), which has an astable oscillator and a long, 21 stage counter, very suitable for extra long delays.

 

[BradtheRad]

There are kitchen timers (also called egg timers).

But to tell the truth, since you want a cycle of 24 hours, it will be easier to use one of the Intermatic timers (operating on mains AC).

The TN311 unit (see post #2) will give you 3 events per day. That happens to be the amount of events you want. It is easy to set the time of day. It is easy to set the time for each event to occur.

It will be a lot of work to make this a homebrew project. It will be hard for you to set its time to real time. You will also have to find a way to set the next event.

Even if your project's time can be set, it will be easy for it to get out of sync with real time.

On the other hand, mains AC provides 50 or 60 Hz, predictably. It is convenient to use. And if you decide to use it, then you might as well use a store-bought timer.

 

[yassin.kraouch]

no body want to answer my question ?

 

[schmitt trigger]

no body want to answer my question ?

You hijacked a thread.
The original discussion was about a long timer covering full day events. Then you jumped in and want to discuss a retriggerable timer.

If you have a similar (but different question), you must start a new thread.

 

[yassin.kraouch]

i already created a new thread but no answer, https://www.edaboard.com/threads/304071/
i did not find a solution yet

 

[schmitt trigger]

I've read the thread you created on "electronic elementary questions", and two different posters give you two different solutions.

The first is with the CD4541, and the other with the 74HC5555. Both can provide very long delays and can be configured to be retriggerable, as outlined in their datasheets.

 

[phongphanp]

Do you mean the error on hot temperature caused the delay out or such a large circuits ?