Simple digital oscillator in a chip driving a transistor on and off I'd
imagine. it need only be small as little dissipation all on or all off.
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Dave Plowman (News)" wrote in message
...
Got a set of Xmas lights. Gawd knows how they do them at the price.
Blue and White. PS/controller gives a variety of programmes. Including
flashing the blue and white alternately, or all on together. But only two
wires from the PS. I can see reversing the polarity could have one colour
or the other, but how both at once with no apparent flicker? Fast
switching?

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*The statement below is true.

Dave Plowman London SW
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