Why do you resists using a ready-made controller to do this? For example, the Siemens LOGO is more than capable of accomplishing this simple task and is probably less expensive than what you could build an analog circuit board for (as long as you put a value on your time).

Siemens LOGO programmable relay

Hi JR,

Thank u for your input; I have checked the specs from the website, it is an overkill if i use this timer for my simple application. I am not sure of the cost per unit.. but i think it is not going to be less than usd 10.

thanks

You may need to check the term analog out.--Analog for what I do is a variable signal--0-10 volts or 4-20mA, typically. It has to be processed to do do anything with it.

Digital is a simple on or off (yes or no, 1 or 0) @120V, 24V or whatever.

You could use two timing relays--There are tons of brands.

Set one relay up for, say 12 hours, and the other for the on duration of what you want switched. You would get an ON, twice a day.

Wire the 12 hour timing relay with a reset through the ON timing relay. To reset the 12 hour timer. Seal the ON timing relay in with it's own contacts.

Tricky, but it can be done easily.

Hope this helps.

Thanks for your reply KT,

Would be nice if u could explain by a block diagram or a simple schematic... I think i get the idea...

thanks

Moomoo,

What is the time you need for ON and when? 12 hour intervals okay?

The relays I use aren't cheap and may not work for your budget. Be specific about the time and how much you can spend and I will look for some--Or if you find them, post a link to the manufacturer and we may be able to help you set them up.

--K T

The on time is from to be adustable from 5 secs to 300 secs. Budget is less than 20 usd for the whole circuit. Basically i want to switch it on at morning once and late evening once, making it a 12 hour interval. The on time should be variable.

Thanks

All kind of time selections here.

http://www.alliedelec.com/catalog/catalogpages/200809/1294.pdf

duration time for timer 1 & timer 2 could be adjusted as shown in catalog that our friend sent before.

yeah, thanks elect-ok, i i'll try that out . Thanks to all the members for their inputs.

Regards

Hi moomoo

If you are into (up to) a little circuit design, here is a site with many circuit diagrams using the 555 (LM555, LM556) timer chip(s) that can fulfill your needs. They can be used to control cheaper mechanical relays for your lights.

It will take some time and probably some trial-and-error to get what you want, but it will be cheaper and you will learn something to boot.

Just a suggestion. Good luck!

Jeff

Hi Snygolfgs,

Thank u, that would be nice indeed! Could u give me the URL please.

Thanks

Hi moomoo

LOL...I apologize for my goof ...I shouldn't do things with only one eye opened.

Here it is:

http://home.cogeco.ca/~rpaisley4/LM555.html

I think you'll find it most enlightening.

Take care.

Hi Syngolfgs,

Thanks for your response.

That was really an eye opener URL!. Thank u for the spirit of sharing and also the same to all the other contributors. Thanks for sharing your knowledge..

I was actually needing a circuit to turn on 9V pump to water my plants two times a day 7.00 am and 7.00 pm at a ontime duration adjustable from 5 to 300 secs. I often go out on long occasions and i dont want want my plants to die of thirst. Bad Karma u know!...

Joy to u

MooMoo

I don't know if you've purchased all the parts yet, but there are systems made for this, and are reasonably priced.

Yes of course Bricktop! I have seen and also got some plant watering systems samples from China. But it doesnt lasts! Short MTBF. Very very unreliable. So i wanna build it by myself. I know there are also some in the US; and these too are imported from China.

Joy to u.!

Glad we could be of some help.

Good luck to you and let us know how it turns out.

Happy Holidays to you.

Jeff

For a similar application I use Omron time delay relays. You can find them on eBay quite often.