M Graff wrote: > Dave Lag wrote: > >> I was going to scale back myself this year,( nothing to speak of - >> half dozen rope lights, snowmen, trees) considering electricity prices >> etc... > > > That's one nice thing about dimmable lights. I can have the same number > of lights installed, but if I just use full-on for effects, and use > half- or even quarter-brightness for most strings, I have a well-lit > house that costs much less to run. > > BTW, I noticed LED bulbs, which I bought several strings of, flicker. I > wonder if that is because they only use half the sine wave and I'm > seeing the 50% duty cycle or if they full-wave rectify and i'm seeing > the 120 Hz zero-crossings... MOST LED strings use half wave rectified AC. As a result they have about a 30% duty cycle since they only light up brightly on the top 1/3 of the cycle so the flicker is obvious, particularly if you pan your eyes across them. I added full wave bridge to mine. Much less flicker, and about twice as bright. Then I added 470uF 220VDC cap to the bridge (per 4 watt string). BRIGHT. Much less flicker. [120VAC 60Hz input. ~150VDC output]. Not sure how long they're going to last now. Have to do some clip leading to be able measure the peak DC current. 5 year warranty . Robert -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist