I replied to this post earlier, but haven't seen it appear on the list,
so assume that it got lost in the aether...

NSM:
What do they know about electrics? FWIW, you could check that the amps are
OK, see what they draw on AC and don't exceed that on DC.
....
Another way, run them up on a DC supply until they operate then add 10% to
that.

I measured the inductance of the solenoid (120mH) and calculated that
the total impedance at 50Hz (R=24 Ohms, Xl=37 Ohms - Z=61 Ohms) would
make for a current of 400mA - less than half the DC current (1A). To
achieve 400mA on DC, I would be putting in only 9.6V.

I'll do tests with a 24V transformer on a Variac - I'm guessing on 12V
DC operation at the moment.

I'll modify my power supply to run at the appropriate voltage and never
again will trust the word of a landscaper on electrical matters, no
matter how convincing they sound ;-)

Many thanks to NSM for these suggestions.

Cheers

M

PS: N - did you try to mail me? My server bounced a "nowrite" e-mail
address earlier today. (It rejects anything that hasn't a real return
address.)