A year ago I decided to make a fully automatic green house, but, because of no free time, I eventually backed out.
Anyway, before getting out of this project I made a circuit that will activate a water pump, for aproximate 2 minutes, every 24 hours.
I combined the circuit from here and the 555 timer monostable circuit from wiki.
R8 – 3M will be the jumpper from a CD4060 output pin (in my PCB you can choose from 2-3) and 555 trigger (pin 2) .
To change the duration of the “on time” you will have to modify the R7 and capacitor value (100k and 1000uF in my version).
This is the equation from wikipedia, where t is in seconds, R is in ohms and C is in farads.
To modify the time of the CD4060 , you have this table :
7 19 Second
5 38 Second
4 75 Second
6 2.5 Minute
14 5 Minute
13 10 Minute
15 20 Minute
1 80 Minute
2 160 Minte (2 hours 40 minute)
3 320 Minute (5 hours 20 minute)
I played with the capacitors, variable resistors and resistors values and i got 24h theoretically, practically I never tested.
Here are pictures of my resulted product :
Here are the pcb layout, silk and components placement.
If you want to build this you need to read the 555 time monostable and the page from the initial schematic because not all modification required are written here.
Credits to this site which, I again say, please read.
If you have any problem or question about this circuit leave a comment or send me an email (email in about page).
I hoped you enjoyed this and, as always, have a nice day!