solenoid valves driven by x10 appliance module problem

["s369180" <yahoo@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Hello,

Last year I bought some of those solenoid valves from RS, which
people have recently been discussing here. It's only now that it is
spring that I have come to use them to water my garden. I have the
12v variety. My set up is this:
1. 240v outlet connected to x10 appliance module
2. x10 appliance module connected to 12v dc psu
3. 12v dc psu connected to solenoid valve

When the x10 signal switches on the psu, although it is supposed to
be a regulated psu it is outputing 15v rather than 12v! The solenoid
valve actuates and my garden gets watered: good, that's what's
supposed to happen... but, and you knew there had to be a but...

When the x10 off signal is transmitted, the appliance module switches
off, however a voltmeter connected across the solenoid valve shows an
output of 0.8v. Do appliance modules "leak" current? I know the
light
modules are supposed to send current to see if a load is connected.
Am I experiencing something similar?

The problem is that the solenoid valve is not closing. If I
disconnect the psu from the valve, the valve shuts immediately. If I
then reconnect the 0.8v the valve remains closed. It seems that 0.8v
is enough to keep the valve open but not enough to throw the solenoid
once the gate is closed.

How can I fix this? At the moment I can automate the water on but not
automate it off! Would a diode in series help by dropping the 0.8v to
0.2v? Perhaps the diode could be a LED to give me a visual sign that
the water is on? Or is it that I am not seeing 0.8v dc but a brief
pulse of ac that averages 0.8v?

Thanks for your help.

Stephen.



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