In Search of Some Ballasts
Posted 30 December 2005 - 01:54 PM
I have a feeling the ballasts might be easier to locate in Europe. I'd be grateful if anyone had any leads.
Posted 30 December 2005 - 02:12 PM
you've probably already tracked them down, but LTMs' US address is:
LTM Van Nuys
7755 Haskell Avenue, Van Nuys, CA 91406
Phone 1 (800) 762-4291
Phone (818) 780-9828
Maybe they can help. If not, is there any reason why an Arri or Strand ballast won't work?
Posted 30 December 2005 - 02:25 PM
I don't know if you can mix-n-match ballasts.
Posted 30 December 2005 - 04:45 PM
Unless it's the same lamp type (and probably in the same housing) there is no guarantee of commonality between HMI ballasts. Different lamp designs require different starting and current regulation.
That said, you could always try building one. I would. But I'm nuts.
Posted 30 December 2005 - 04:51 PM
+44 (0) 20 7582 8750 or firstname.lastname@example.org
Not sure if they still have it
Posted 03 January 2006 - 01:35 PM
A salesperson at Bron Kobold called the 270's 'extinct'
LTM Paris open up again on the 6th. I think they might be my last hope, unless...
Anybody know how to make an HMI ballast?
Posted 04 January 2006 - 03:48 AM
I am the original DIY guy, I've cobbled up all sorts of work-arounds but I hit a blank wall when I tried to improvise a ballast for my project. I did learn one thing from GE: hot restrike lamps do not have to be operated on a hot restrike ballast, they will work correctly off a properly designed ballast, in fact they last longer if NOT hot restruck.
Posted 04 January 2006 - 09:49 AM
As long as you can find out what the lamp current is supposed to be when it's running, it should be possible to build a ballast. You might end up hand winding some inductors and doing head-bending mathematics in the design phase, and it would be most ideal to know what the strike range is (at least so you can find out if this is the reason it isn't starting properly).
Probably the easiest way to do it would be to use one of the standard switched-mode power supply controller ICs and an array of large MOSFETs, but you would almost certainly be winding custom inductors and it can be quite difficult to design these things to be highly efficient (although flicker-free is easy).
I should imagine it would be quite easy to drive them badly without knowing it.
Posted 04 January 2006 - 01:28 PM
Call Tony - UK lunch times
Or if it doesn't work out or is too much then I am sure you can build one