Several months ago, I acquired two US-market Philips White SON (HPS) lamps in 100W.

https://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=0&pos=22&pid=258147
https://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=0&pos=23&pid=258146

 It was insane enough that I found them for sale on eBay, but the ballasting system they use might as well not exist. These lamps require a White-SON-specific S-105 ballast. As far as I know, there is only one S-105 ballasting system in existence, the Advance 71A8005, which I can’t find for sale anywhere. And I certainly don’t anticipate finding one anytime soon. I don’t think any other manufacturers made such a ballast, so it’s only that one Advance model. So I was wondering, is there an alternative ballasting setup that I can use to illuminate these lamps? From what I understand, the “white” part of these lamps is enabled by a special igniter specific to these lamps, and the ballast itself is more or less ordinary. Provided it can be done easily and safely and it is known what components/circuit design are required, would it be possible to create a DIY igniter? Or if anyone knows where I can get an Advance 71A8005 ballast/ignitor, please let me know. Thank you for the help! 

Do you want to light up this lamp just for fun once or you want to use it permanently?

May be American S54 or S55 with an extra choke in series will be OK to try.

SDW lamps do not need a special ignitor significantly different from regular metal halide lamps. But for long term use they need a current to be regulated in a special way. First, line voltage variations are need to be controlled in somewhat tight range, second as the lamp ages, power applied should be reduced to keep the color. In Europe, at 230V this is done by a specialized electronic gizmo, basically a specially controlled TRIAC phase dimmer in series with magnetic choke, or the lamp is just lighted on a custom electronic ballast made by Philps.

 

Hi, i had similar issue, try to search Philips primavision electronic ballast, if you are lucky enougth, you'll find cheaply 

There are still NOS drivers for SDW-T and -TG 100w available on various european web shops.
I have no clue of there is much of a difference between those, and what your lamp was used with originally.

Do you want to light up this lamp just for fun once or you want to use it permanently?

May be American S54 or S55 with an extra choke in series will be OK to try.

SDW lamps do not need a special ignitor significantly different from regular metal halide lamps. But for long term use they need a current to be regulated in a special way. First, line voltage variations are need to be controlled in somewhat tight range, second as the lamp ages, power applied should be reduced to keep the color. In Europe, at 230V this is done by a specialized electronic gizmo, basically a specially controlled TRIAC phase dimmer in series with magnetic choke, or the lamp is just lighted on a custom electronic ballast made by Philps.

 

I didn't know that SDW lamps don't redding out near EOL like regular HPS lamps do on the correct equipment. I only thought that with a regular HPS/MH their color shifting range is very wide and that they simply don't have a stable 2500K all the way of their life (As you see, this is caused by line voltage variations), as I've seen in supermarkets and shops.
I would be interested if they still passes mercury color near EOL on the correct equipment.

@RRK - Thanks for clarifying. I would only be illuminating the lamps temporarily as a test, not for regular service. If I happen upon an S54 or S55 ballast, I will definitely try one. What kind of choke would I need to put in series?

@marcopete87 - I don’t think those are compatible with the American spec White SON lamps.

@Laurens - I don’t think the American White SON lamps have the same electrical specifications as the European ones, so I don’t know if any European White SON ballasts would work with them.

Well, my guess on S54 is based on the fact that Philips decided to homologate European SDW lamps parameters with regular SON lamps of the same wattage, only dropping the power further as the lamp ages. *May be* but not certain that Philips did the same with their American low-voltage SDW, homologating them to American low-voltage SON. If so, a new lamp will run more or less OK on American low voltage SON gear.

Some caveats:

SON lamps generally require ~1.5kV peak ignition voltage while SDW, at least European ones, are rated to full MH-like 3.5-4.5kV. So SDW lamp may refuse to ignite on a regular SON ballast.

SDWs, having just bare tungsten rods as their electrodes, none of starting aid thin tungsten wire coils as with most HIDs, are having troubles to attach the arc and do glow-to-arc transition for quite long time after being turned on. May be up to 30 seconds for both SDW and SDW-t, even on electronic ballast. So the lamp flickers a lot at start, don't be surprised, this is normal.


Regarding extra chokes. If American SDWs are in fact homologated to low voltage American HPS, 100W S54 will fit directly. 150W S55 will need to add some extra impedance in series to drop the current a bit. Something relatively low, I don't know what you have on hand, may be even a secondary winding of some high-watt CWA or HX transformer with a primary shorted.
 
It is relatively easy to tell if SDW is running at optimal power by monitoring its color and if you can, an inverted black gap over a sodium resonant orange line in the spectrum. If underdriven, SDW will never run up to its proper color, and will look like a regular SON color with relatively narrow gap in the spectrum at orange. If overdriven, the lamp will pass its optimum golden color at 2500K CRI 85 as it is running up and will become dim blueish-whitish with a very large black gap in the orange part of the spectrum.  Turn it off immediately and attempt to reduce the current.