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?

--
*The statement below is true.

Dave Plowman London SW
To e-mail, change noise into sound.

On 13/12/2016 00:23, Dave Plowman (News) wrote:
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?

Yup pretty much... Throw a bit of PWM into the mix as well, and you
should be able to get dimming and fading effects as well.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

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

--
----- -
This newsgroup posting comes to you directly from...
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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?

--
*The statement below is true.

Dave Plowman London SW
To e-mail, change noise into sound.

and quite a lot of radio interference I noticed a few years ago when messing
around with a radio near a shop with them round the window.
Brian

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

Blind user, so no pictures please!
"John Rumm" wrote in message
o.uk...
On 13/12/2016 00:23, Dave Plowman (News) wrote:
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?

Yup pretty much... Throw a bit of PWM into the mix as well, and you should
be able to get dimming and fading effects as well.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 13/12/2016 00:23, Dave Plowman (News) wrote:
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?


Julian Ilett explains two-wire pulse-controlled RGB LEDs here. Not sure
if your blue/white is exactly the same.

https://www.youtube.com/watch?v=gxdgRHmOuIo

--
Reentrant

On 13/12/2016 09:16, Reentrant wrote:
On 13/12/2016 00:23, Dave Plowman (News) wrote:
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?


Julian Ilett explains two-wire pulse-controlled RGB LEDs here. Not sure
if your blue/white is exactly the same.

https://www.youtube.com/watch?v=gxdgRHmOuIo

That was interesting, thanks, I have some of those.

His video makes me wonder if they could be 'randomised' by first sending
lots of low pulses of ever decreasing length between say 500us and
100us, then switching to a fixed 20us pulse regime.

I think that would make a more interesting display.

Cheers
--
Clive

Dave Plowman (News) wrote:
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?

Fascinating devices.
Googling for NorthLight products (as seen in the videos) suggest Clas
Ohlsen but the site say discontinued maybe sold out until next Xmas perhaps?
Anyone found a supplier with stock?

On Tuesday, 13 December 2016 02:54:08 UTC, John Rumm wrote:
On 13/12/2016 00:23, Dave Plowman (News) wrote:
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?

Yup pretty much... Throw a bit of PWM into the mix as well, and you
should be able to get dimming and fading effects as well.

It's more than just PWM it's IC2 which uses atmel contollers to control each individual LED is possible .

https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1


https://www.amazon.co.uk/d/Indoor-Li...A38G67QEAA9E03


we have this sort of thing on our lab christmas tree it has a remote control I can set almost any colour and slow of fast transitions. Last time when two studetns were doing selfies with my tree I used teh remote to turn it off, they looked worried as they thought they'd broken the lights. :-)

So it might be that a dedicted xmas tree light setup uses the above and possibley even cheaper.

On 13/12/2016 11:33, whisky-dave wrote:
On Tuesday, 13 December 2016 02:54:08 UTC, John Rumm wrote:
On 13/12/2016 00:23, Dave Plowman (News) wrote:
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?

Yup pretty much... Throw a bit of PWM into the mix as well, and
you should be able to get dimming and fading effects as well.

It's more than just PWM it's IC2 which uses atmel contollers to
control each individual LED is possible .

https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1

The RGB LED strips are a somewhat more sophisticated setup than many of
the cheap two wire sets of lights though. However the posh versions of
them can do quite impressive lighting effects.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
whisky-dave wrote:
On Tuesday, 13 December 2016 02:54:08 UTC, John Rumm wrote:
On 13/12/2016 00:23, Dave Plowman (News) wrote:
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?

Yup pretty much... Throw a bit of PWM into the mix as well, and you
should be able to get dimming and fading effects as well.

It's more than just PWM it's IC2 which uses atmel contollers to
control each individual LED is possible .

https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1

Wouldn't expect Amazon to provide any real details, but the pic shows a
four pin connector. Which would allow three different colour LEDs to be
driven in any way you can think of.

That wasn't what I was asking about.

--
*Beauty is in the eye of the beer holder...

Dave Plowman London SW
To e-mail, change noise into sound.

On Tuesday, 13 December 2016 13:14:19 UTC, Dave Plowman (News) wrote:
In article ,
whisky-dave wrote:
On Tuesday, 13 December 2016 02:54:08 UTC, John Rumm wrote:
On 13/12/2016 00:23, Dave Plowman (News) wrote:
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?

Yup pretty much... Throw a bit of PWM into the mix as well, and you
should be able to get dimming and fading effects as well.

It's more than just PWM it's IC2 which uses atmel contollers to
control each individual LED is possible .

https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1

Wouldn't expect Amazon to provide any real details, but the pic shows a
four pin connector. Which would allow three different colour LEDs to be
driven in any way you can think of.

Yes I know and that was brought last year.
I can't think of why they don;t multiplex the control signals with the power, simialtr to the way old mians wireless intercomms work.
Maybe that should be a studetn project.


That wasn't what I was asking about.

--
*Beauty is in the eye of the beer holder...

Dave Plowman London SW
To e-mail, change noise into sound.

whisky-dave wrote:

Dave Plowman wrote:

the pic shows a four pin connector. Which would allow three
different colour LEDs to be driven in any way you can think of.

That seems to be the type with GND and a separate power to all the R/G/B
in parallel, i.e. no individual control of LEDs, but with PWM you can
drive the whole string to any colour.

Yes I know and that was brought last year.
I can't think of why they don;t multiplex the control signals with the power, simialtr to the way old mians wireless intercomms work.

Some of the new ones available this year seem to do just that, just a
GND and +5V rail, with colour data sent as brief pulses to 0V on the 5V
rail.

"Brian Gaff" writes:

and quite a lot of radio interference I noticed a few years ago when messing
around with a radio near a shop with them round the window.

Fairy lights are a well known cause of poor ADSL connections.

--
Alan J. Wylie http://www.wylie.me.uk/

Dance like no-one's watching. / Encrypt like everyone is.
Security is inversely proportional to convenience

Andy Burns submitted this idea :
whisky-dave wrote:

Dave Plowman wrote:

the pic shows a four pin connector. Which would allow three
different colour LEDs to be driven in any way you can think of.

That seems to be the type with GND and a separate power to all the R/G/B in
parallel, i.e. no individual control of LEDs, but with PWM you can drive the
whole string to any colour.

Yes I know and that was brought last year.
I can't think of why they don;t multiplex the control signals with the
power, simialtr to the way old mians wireless intercomms work.

Some of the new ones available this year seem to do just that, just a GND and
+5V rail, with colour data sent as brief pulses to 0V on the 5V rail.

A neighbour seems to have a set which are RF synchronised. They have a
set in a ground floor window and an identical set in a first floor
window at the opposite corner to the first set. Both flash at the same
rate, showing the same colours etc. at the same time.