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I have a Rayton R3 UVB lamp for phototherapy. It consists of a this PL-S 9W/01/2P bulb with a G23 base, and the ballast is magnetic 120v/60hz.
I would like to swap the ballast for a 240v/50hz ballast, and all I've found is a universal electronic ballast (here) but Wikipedia and others say that two pin lamps are designed for conventional (magnetic) ballasts. Does that mean that an electronic ballast should not be used? Can you tell me if the linked ballast is compatible?
The given phototherapy tube is a glow start tube with filaments. The glow starter is built into the base. Glow start tubes are usually driven with conventional magnetic ballasts. There might be also electronic ballasts for 2 pin tubes with built in glow starters, but usually electronic ballasts need access to all 4 pins of the tube.
The given listing for "universal electronic ballast" is lacking in details (input voltage/frequency ranges, tube current etc.) to give any recommendation for it's suitability.
I'd recommend replacing the existing ballast with an European model. For example: http://www.lighting.philips.com/main/prof/lighting-electronics/fluorescent/fluorescent-electromagnetic/bpl-em-ballasts-for-cfl-pl-t-pl-s-and-pl-c-lamps/913710122350_EU/product or https://www.helvar.com/en/products/L11D240V50Hz/ or any other magnetic ballast with correct frequency, voltage and lamp power. Also when converting the wires might need also upgrading for the higher mains voltage. Consult a local lamp repair shop for advice.
Added, since unable to comment:
Suitable search terms to try on your favorite online platform: "magnetic ballast 9w" "Helvar L11D" "pl-s ballast".
Fluorescents are arc-discharge lights, meaning like neon where a high voltage runs the length of the tube, and that arc must be initially struck on startup. 2-pin simply means the lamp does not have electrode preheaters for gentle startup. They are built extra tough to handle this.
So a 2-pin ballast needs a somewhat higher startup voltage. That is not a significant difference, if anything it makes the ballast simpler than a preheat ballast. So yes, it can easily be an electronic ballast.
For instance you see the same dichotomy on 48" fluorescent tubes, rapid/programmed start ballasts use the preheaters, instant start ballasts do not. Both are electronic.
Once the arc is struck, the tube needs something to limit current. That's tge other job of the ballast, and why they call it a ballast. Again not a problem to do that in an electronic ballast.
Getting rid of buzz and flicker is still desirable, so I'm sure somebody makes an electronic ballast for your types of bulb.
Not sure I would trust a no-name ballast brand from eBay, though. I would gravitate toward companies with an actual history at making ballasts, like GE, Philips/Advance, Sylvania and others often seen on sites like 1000bulbs.com.
I know in the early 2000's the U.S. outlawed magnetic ballast the universal ballast is based on voltage they use 100-277v where the old mag ballast have a specific voltage 120v, 240v,277 as a common in the US now all 3 of these if the same lamp type use 1 type of electronic ballast. You do need to match the ballast type with the lamp if not sized properly the lamp or the ballast will have a shortened life span. The hospital I worked at used some photo therapy (in Oregon) for SAD treatment and we also had white light fixtures with the g23 base that we converted to electronic ballast. Don't go cheap I know the early electronic ballast were a high failure rate item but still find the failure rate high on electronic ballast if not a quality brand compared to the old magnetic ballast that lasted for decades.
