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I've just refurbished a couple of old machine lamps for use in my workshop. In the olden days I'd have put a filament bulb in these for flicker free lighting on rotating machinery. What does one use these days? I know some compact fluorescents and some leds do flicker but do they all? Obviously I don't want any strobing effects.
LED's will strobe, it's the way they work. It's one advantage that incandescent filament bulbs have.
Could you use 12v halogen bulbs?
Actually, there's nothing intrinsic to the LED that means it flickers, it's just that the most convenient (inexpensive) way to build a circuit that drives them causes flicker. So there [i]could be[/i] flicker free LEDs on the market, but good luck finding them clearly labelled as such.
Interesting paper from [url= http://www.cree.com/led-components/media/documents/Flicker.pdf ]Cree[/url]
Shame that Flicker Index and Flicker Percentage aren't reported for products.
Use halogens?
http://www.screwfix.com/c/electrical-lighting/light-bulbs/cat8350001#category=cat8350001&lamptechnology=halogen
LED's will strobe, it's the way they work.
Most cheap mains bulbs will as they just half rectify ac to power them.
If you power 12v ones off a decent DC PSU, you won't get any strobing.
Some bulbs will do power factor correction and the voltage step down in a single stage and they will have a inherent 2x mains frequency ripple (100Hz) which would cause strobe effects. The cheapo dial LED filament bulbs I bought from b&q a while back didn't have power factor correction and were therefore ripple free.
You'll probably have to buy a few different types and test them.