> > Why have the 'bridges' between the parallel strings of LED's?
> 
> Don't know. The LEDs won't be conducting half the time. It 
> would help with assembly a bit I guess, as you'd solder two 
> LEDs in anti- parallel and then join them to the next pair. Maybe ?


Has any ever made a bridge out of LEDs?  It rectifies and lights up!

I've seen LEDs run off mains simply by using a resistor.  The last one I saw
was in one of those cheap main filter things.  Not the best for a lamp, but
it seemed to work ok as an indicator, if the layer of dust was any guide to
its age. 

Usually it's a physically large resistor, either because dropping 240v
produces a few watts or to give a large gap for isolation in case something
goes wrong (sure!), but sometimes 2 or 3 small wattage ones in series.  The
series method is for the really cheap stuff.

Tony

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