Please be careful in knowing that a F40T12 ballast, a European 80W mercury vapor ballast, a North American 75W H43 mercury vapor ballast, or a North American 100W H38 mercury vapor ballast WILL QUICKLY OVERHEAT AND CATCH FIRE IN A MATTER OF MINUTES WITH THE ND20 low pressure sodium lamp due to the lamp’s extremely low arc voltage drop. THESE BALLAST SUGGESTIONS ARE EXTREMELY DANGEROUS AND MUST BE AVOIDED AT ALL COSTS.

Thanks for the info!

These are all interesting ideas, but do any of these result in significant ballast losses or could be used in security lighting?

Hello,

My first try would be a leak transformer for an 90W SOX lamps.

Regarding the ballast of an 80W fluorescent, I suspect that RRK means the soviet 8ft fluorescent tubes and balasts?

I certainly think that these ballast are overloaded at such a low lamp voltage drop, however id need the exact ballast data to tell anything about how quick in would catastrofically fail. However I personally and this is my opinion you shold be fine with runnig that for short times / testing purposes.

Soviet/British 80W 102V 865mA 5ft tubes. Ballast sure runs hot but OK for a reasonable time. About the same as running in a circuit with a stuck starter. One may set up a little fan to keep the temperature low enough BTW.

These are all interesting ideas, but do any of these result in significant ballast losses or could be used in security lighting?

No easy way with off-the shelf ballasts. But I doubt these Chinese lamps (and all spectral lamps also) have enough lifetime to be considered for general lighting. More of scientific toys with some hundreds hours (at best) of life.