In article <mn.e5297dd4ee26ba91.127094@snitoo>,
Snidely <
snide...@gmail.com> wrote:
> On Sunday, Hactar queried:
>
> > So I have this crazy idea of rigging up a switch and 14 9v batteries in
> > series (they have these convient terminals) and using that to power an
> > LED rope light to decorate my wheels. How do I find out if a rope light
> > works on DC? I have no diodes or test equipment at home. I figure
> > someone in the Engineering department at the local university (at
> > I'm a student) can test it, but short of pounding on likely-looking
> > doors, anyone have a good idea? The rope appears to flicker, but I don't
> > know if it's the whole rope on for half the cycle then off for half the
> > cycle, or two halves of the rope taking turns being on.
>
> Ikea has LED light strings that run on 2x AA cells,
Right, those are all over the place. But they're not protected in a
vinyl tube. What I've done in the past is manually put one of those
in a 1/2"-5/8" clear vinyl tube from e.g. Lowe's.
> as well as ones
> that run on 110V AC. The former, in it's snowflake incarnation, has 10
> lamps well spaced over a 6 ft span, which may not be dense enough for
> the effect you want.
It's not. What I've been using is two strings per wheel. What I'd like
to do is have a power distribution network with one master switch and a
6v battery and then have a voltage converter on each wheel, but I'd
need a slip ring to pass the power to each wheel. Those are easily had,
but I couldn't find a way to get/make one that would come apart and have
the pieces be physically robust. I mean, sometimes the chair gets put in
a car trunk, which is dirty and there are forces in odd directions.
Maybe some kind of inductive thingy would do, like in an electic
toothbrush base, but that sounds complex.
> The string with the stars uses a wall wart to put
> 24VDC on a 15' string, but I didn't count the stars. More than 10,
> though.
I'd probably get a string, so I can make some design that sticks close to
the spokes (it's a bicycle-style wheel) for robustness. But that's a
good idea -- find a rope light with a wall wart, then I KNOW it works on
DC. Plus 24 VDC is a bit safer than 126 VDC. I might approximate
24 ~= 3*9 because that's a lot more compact than 24 = 16*1.5, and that's
only a 12.5% overvoltage. Or 24 = 2*9 + 4*1.5, but mixing battery types
like that bothers me though.
> I used to have actual rope lights, but I'm not sure I waited long
> enough to get LED ones.
LED is practically a requirement if you're running from battery.
Incandescent bulbs will drain a normal-size battery in a day or so.
> I think I have an indoor/outdoor string of LED
> lights that imitate the mini-bulbs that dominated for the last 30
> years, but it isn't anyplace convenient, so I don't expect to disect it
> soon.
Thanks. Maybe attacking this string with a multimeter would be
informative.