rotating machines & flourescent lights

Still widely available.

As a lot of metal working machines involve quantities of coolant sloshing about, the work lamp would normally be 50v or lower for safety and 50v GLS still seem to be readily available.

Very common, if not universal, as a work light on modern metal working lathes etc.

High frequency fluorescent lights.

Colin Bignell

I've never considered it a great risk in a home workshop, as usually there's only the one person working there and only one machine tool at a time. Even if it looked stationary, the noise would tell the operator that it is running. It'd be an entirely different matter in a workshop with multiple machines running and a number of people.

SteveW

That did apply once, but now only to cheap fittings. Decent fittings will run at a much higher frequency than mains which increases efficiency. And removes the strobing problem.

On Sunday 20 October 2013 17:50 jim wrote in uk.d-i-y:

? Plenty still available.

phase

Most ordinary fittings still just have choke type ballast and run at

No the lamp still flickers, it moves the apparently static tool to other rotational speeds which may or may not be a problem.

I'd be surprised if the phosphors in the tube react at all to frequencies around 30,000 Hz.

A long time ago when i was working, leans on old walking stick.. I recall special lights whos phospher was long persistance or something like that, for this very task of lighting in areas where lathes and such were sited.

Do these still exist? I never liked the light from them, it seemed cold to me at the time. Brian

Failing a three phase supply with lights on separate phases, there used to be special twin fluorescent lights where one tube was phase shifted. This produced continuous light. Eg

The discharge in the tube becomes continuous when operating at 5kHz because of the ion decay time (and this is also why there's an increase in efficiency as you get to 5kHz). All electronic control gear operates well above this, so no high frequency strobing is possible.

Or putting them on the other two phases, if three pahes is available, but HF is the better option.

Andrew Gabriel formulated on Monday :

More efficient due to no energy being wasted heating the ballast up.

Electronic ballasts give off less heat, but the tube itself gets around 10% more efficient as the operating frequency goes up past

One method was lead and lag pairs, using inductive and capacitive ballasts, since the light peak occurs at different times. Simon.