They do, but the strobe is at a higher frequency and with less difference between the highs and lows (lamps tend to use phosphors that don't have much persistence) This may or may not cause machines to appear stationary depending on the rpm. Some woodworking machines run at several thousand RPM so may well appear stationary even with electronic ballasts. I would use tungsten lights and be safe.
Err. No. All (recent) electronic ballasts use frequencies over the audible range. One I just had my scope on used 60Khz, and that's about typical. Leading to 120Khz flicker. If you are running woodworking machines at 7 million RPM, can you please post first, so we can duck?
Do you still wear gloves on a piece of elastic threaded through the sleeves of your anorak ?
Well, I guess youre right. Fl tubes had crept up to 100lm/w in 2000, with LPS at 200 lm/w and hps 140 lm/w
NT
You are assuming that the rotating part doesn't have a pattern on it.
The speed the strobe runs at is not going to stop the effect. It will only alter the way it looks.
What would save you if you were running the tube at 60kHz is the persistence of the phosphor which would eliminate the strobe effect entirely.
I have never seen one that runs that high before.
Had ordinary strip lights in my wood workshop for years with good visibility and absolutely no problem with flicker or anything else (except colour photos require filter - no prob with digital however). Diffused light is essential, tungsten or other small bulbs would be a problem, except for occasional use of large anglepoise type lamp for close up work. Handy to fix striplights on chains or similar, with flexes so that they can be re-positioned if necessary.
cheers Jacob
lol
I wonder if things will ever go that way, maybe in another 300 years they'll have small light hand drills with motors doing turbo type speeds. And costing =A35 for a 1kW drill.
NT
Useful comment there.
Tungsten is safe for all woodworking machines and it is more compact, making fitting to the machinery easier. Fitting fluorescent lighting requires more careful choice and maintenance, so tungsten is easier, cheaper and safer for localised lighting of the machinery.
If it's got 100 radial stripes, that's 'only' 70 thousand RPM.
The several I've measured in the past are all about that. The simple reason is that the electronics are cheap to produce at that frequency. Higher, and the transistors become expensive. Lower, and the passive components do.
For decent white light, with reasonable colour rendition, 200 or so is the hard physical limit. So common tubes are getting moderately close.
white LEDs are at maybe 40lm/W or so, with optimistic assumptions.
Modern fluorescent tubes are very efficient, mostly flicker free and not that expensive.
Then add in spotlights where you have need of high specific illumination.
When you get to somewhere around 5kHz, you will find the mercury electrons will not yet have decayed from the last half cycle, so the discharge becomes continuous (and this is what results in a
5-10% increased light output from electronic control gear). Since all electronic control gear runs well above 5kHz, the persistance of the phosphor is irrelevant in this respect.What you can find with cheap electronic control gear is that the internal supply has 100Hz ripple on it which comes through into the final light output.
It doesn't work like that. One of the two speeds only has to be a multiple of the other for it to appear stationary. They don't have to run at the same speed.
The phosphours have a persistence of about 1 mSec so anything above 1kHz shouldn't flicker much. I would still avoid them as localised lighting on machines though. You don't have to worry about ripple or any other problem causeing flicker if you have a tungsten lamp on the machine.
Its just age showing through.. take the easy option when you *know* it will be safe.
This is one of the problems.. you can't see 100Hz ripple but it will act as a strobe. It means you can't detect a faulty control unless you notice your moving machine is strobing. Not very safe IMO.
Yes - but only for strobes. For other things, it's got to be a very small multiple of the other, as otherwise it just blurs out. Even neglecting persistance in the phospohor.
Dr Dribble will probably claim some oddball pseudo premium manufacturer has been making these for years. They allegedly go like zippo and are so cheap compared to "filthy chinese produced japanese branded crap" you can buy a dozen "just in case" and they have a 5 year guarantee you will never need to use.
They would need to have fine patterned components or be rotating extremely fast.
I have a variety of woodworking machinery and have not observed this effect at all.
I wouldn't. It isn't bright enough unless you have a very large amount of it.
I think this is something that would only go wrong fairly rarely, as everything needs to be just right for something to appear stationary. Rotation and mains freq need to be an exact multiple, and not too high one either else you end up with so much blur that it stil doesnt look stationary. Most of us will have seen a record deck speed check disc strobing on filament light.
Its also possible to paint angled stripes on the chuck to avoid this problem, such that as the chuck rotates it appears to be moving at 90 degrees more slowly. Paint 2 sets, each moving towards the other, and movement is even more evident, even in synchronised strobe conditions.
NT
A 100w halogen at 2ft is brighter than a 60W tube at 6 feet.
The message from "dennis@home" contains these words:
I've a couple of 4' fluoros for general lighting and a couple of 150W halogen clipons (the things like security lights without the PIR bit) which I move around the roof timbers as needed. Works well for me.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.