Re: Automatic watering

[ian.bird@xxxxxxx]

Must be something simple like this otherwise it would not be possible to
run it off a battery. The valves I use consume about 230ma each to stay
open but close when the power is removed. I would guess the original water
computer only pulsed the magnet for a second or so in either direction for
open and close. Stating the obvious really but it was fun.

This type of behaviour will make tracking the valves state a tad harder
than with the auto close variety. You might like to consider a flow sensor
as I installed which I use to check if after closing the valve the water
really has stopped flowing. It was from Farnell and not too expensive. Ask
away if you want more details as I have not added this to my site yet.

Ian







"Tim Fletcher" <timfletcher@xxxxxxx>
03/12/2003 11:54
Please respond to ukha_d


To:     <ukha_d@xxxxxxx>
cc:
Subject:        Re: [ukha_d] Automatic watering


reverse the polarity to close the valve?

----- Original Message -----
From: Rob Lamb
To: ukha_d@xxxxxxx
Sent: Wednesday, December 03, 2003 11:48 AM
Subject: [ukha_d] Automatic watering


I need a little help with a new project. Up until now I've used a
standalone Gardena water computer to control my irrigation system
but as this now seems to have failed and I now also have Homevision
I thought I try to control the valve part of the water computer.
Taking the water computer apart there are just a pair of wires that
lead to what looks like an electromagnet on the valve. Connect 9V DC
to these leads (that's the same as the battery the computer used)
and hey presto water flows through the valve. But here's the
problem. Disconnect the power and - the water still flows! Any ideas
on what I'm doing wrong or what to do next?

Regards,

Rob



[Non-text portions of this message have been removed]