mapj1:
Rather than waste power on lossy resistors a lot of the cell saver designs of torches do the dimming from anything other than full brightness by chopping the current waveform, so half brightness is the same as full brightness for half the time.
Normcall:
The 'twin packs' of 6ft fittings were produced mainly for commercial projects. They were single 6ft fittings sold in pairs - one lead/one lag - to correct the power factor when used in shops/factories which often had 3 phase supplies and getting the PF as near to unity could save money.
mapj1:
Rather than waste power on lossy resistors a lot of the cell saver designs of torches do the dimming from anything other than full brightness by chopping the current waveform, so half brightness is the same as full brightness for half the time. What I do not understand is why the makers elect to do this slicing at low audio frequencies, rather than hundreds of kHz, which is just as easy for the electronics and would avoid the worst of the weird optical illusions.
I do seem to be 'gifted' with the ability to see flicker more than most, and to me the overhead motorway variable speed signs flicker as well, and asking at work, most people have not noticed it, but those of us who do agree it is bloody annoying.
Chris Pearson:
AJJewsbury:
I have occasionally noticed flicker from LEDs ...Now you mention it, whilst drilling the fixing holes for a back box today and using a head torch for illumination (no mains lighting for obvious reasons) I thought of this and noticed that my drill appeared to be going backwards; so clearly, even battery powered LEDs must flicker.
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