i do not know how to do a timing circuit..
i will be using it a switch to an ac load..
i only know lm555..hehe

 

Can you describe in greater detail what specific timing circuit you would like to design?

Maybe you can indicate your timing circuit application to better focus your question.

hgmjr

 

If you interest is in switchg a load after a period of time, look up time dealy relays in google.

 

i will be using it to automatically turn on/off a water pump for a specific period of time