That sounds like overkill for a "small" lathe. I have a 4 ft fluorescent tube above mine.

Even if there is a stroboscopic effect, it should be manageable. I can see that in a workplace, somebody could approach a lathe and not realise that it is turning, but even then surely the motor would be heard. If it is just your workshop, and you happen to have it turning at just the right (or wrong) speed, you must know that it is on.

I sometimes use an LED head lamp when I want especially good illumination and that does have a stroboscopic effect, but it is not the only illumination so I can still see that the lathe is turning.

I would say that the real issue is whether this is a place of work or not because the Health and Safety at Work etc. Act 1974 and its subordinate legislation impose much tighter controls than in the domestic environment.

That sounds like overkill for a "small" lathe. I have a 4 ft fluorescent tube above mine.

Even if there is a stroboscopic effect, it should be manageable. I can see that in a workplace, somebody could approach a lathe and not realise that it is turning, but even then surely the motor would be heard. If it is just your workshop, and you happen to have it turning at just the right (or wrong) speed, you must know that it is on.

I sometimes use an LED head lamp when I want especially good illumination and that does have a stroboscopic effect, but it is not the only illumination so I can still see that the lathe is turning.

I would say that the real issue is whether this is a place of work or not because the Health and Safety at Work etc. Act 1974 and its subordinate legislation impose much tighter controls than in the domestic environment.

I thought the phenomena was more to do with lights on different phases in the same area? I wouldn't have thought single phase would be noticeable.

any one light is dimmest at the zero-crossing of the sinewave current of the phase it is on.

Before electronic ballasts and large enough capacitors to hold up the volts over the gap existed, the old school fix was florry lights that had two tubes on different phases, or if only 1 phase supply available then an L-C phase shift network to delay the waveform to one lamp, and not the other. In effect creating another phase locally -rather like the capacitor start for a 1 phase motor.

Indeed special "workshop fittings" were made with this extra phase shift ballast arrangement.

The aim is to ensure that the light level is not varying periodically, or at least not by so much as to matter and give the film wagon wheels going backwards illusion.

Mike.