supply electrode with the humidity of the soil

[GPG]

I tkink I use first ne555 for temporisation 10 minutes and 7 secondes , and the second ne555 create 500hz signal .

is it right ?View attachment 22691

I tkink I use first ne555 for temporisation 10 minutes and 7 secondes , and the second ne555 create 500hz signal .

is it right ?View attachment 22691

Should have refreshed. Yes it could be done that way.

 

[hagi]

I will use 12V from supply adaptateur, or else I could use 9V with 7809 .

 

[GPG]

Can you obtain this
http://www.analog.com/media/en/technical-documentation/data-sheets/ADG419.pdf
Or http://www.vishay.com/docs/70051/dg417.pdf
It will be driven by the electrode signal and selectively respond to that.

 

[hagi]

I did not know analog swith , I will watch examples of application on the internet.
I have found the schematic

 

[CDRIVE]

This might be considered old school since it would include a relay but the 555 can be used to cycle a DPDT relay wired the same way they're used to reverse polarity for DC motor direction control. Come to think of it a DPDT relay wired in this configuration constitutes the electromechanical equivalent of a solid state H Bridge, so that might be doable too.

Cheers,
Chris

 

[hagi]

http://www.circuitsproject.com/2014/02/an-electronic-watering-can-circuit.html