On Wed, 21 Nov 2007 08:20:59 -0800 (PST),
wrote:

Hi. thanks for the detiailed response JF.

I'm using the following solenoid: www.radionics.ie : RS Part number
search (top of page): 431-7560
(19mm push, 12V)

I'm looking at about 3.5% duty cycle.
It says on the datasheet(
http://docs-europe.electrocomponents...6b805c2a1f.pdf)
that the wattage increase by the square of the increase in voltage.
12-72 = 6x increase so 36x increase in wattage. (1/36 for the duty
cycle)
7W at 100% duty @ 12V so we're looking at 252W on 72V on a 3.6% duty
cycle.

Unfortunately they don't mention current or resistance in the
documentation but I can go and measure tonight.


According to my RS website page RS 431-7560 is manufactured by
SAIA-BURGESS http://www.saia-burgess.com/2302/2303/2310/2316.asp which
owns the LEDEX brand http://www.ledex.com/ of STA linear solenoids
http://www.ledex.com/linear-solenoid...solenoids.html

(You will be requires to register)

The STA LEDEX part no. for the RS 431-7560 is 195225-230 for which the
data sheet is Metric STA 20 x 40
http://www.ledex.com/ltr2/access.php...20x40_Push.pdf

On this page
http://www.ledex.com/solenoid-applic...solenoids.html you
will find applications for linear solenoids some of which may be what
you are trying to accomplish.

Also, I would suggest that you read as much as you can on the LEDEX
website including
http://www.ledex.com/ltr2/access.php..._Section_M.pdf

When using your solenoid at the nominal voltage of 12V you can leave
it permanently connected without overheating but if you wish to
increase the voltage then you may be wise to use a LEDEX Hold-in
Circuit Module as described on page 6 of the last document link.

If you need help then I am sure that LEDEX will be able to answer your
queries.

Good luck!