Hi All,

I would like to put some solar powered lights in the 20' x 10' x 8'
(to eaves) workshop, mainly just to be able to see in there to move
about rather than work as such. I don't have power down there all the
time atm (long story) and even if I did (and in the spirit of d_i_y) I
still like the idea of 1) making use of some of this kit [1] and 2)
having some alternative lighting in there.

So, I don't mind having a few unit, say one on each of the 5 roof
trusses and a pull switch by the door to turn them on and off but what
is currently the most efficient and good vfm please, LED or CF /
Fluro? 12V inverted up to ~600V or regulated down to 5 etc?

I was thinking those tubular 12V x 8W fluro inspection lamps
(typically a fiver) or LED equiv held under the beams by a couple of
Terry clips each (as that way they could be easily pulled down to
replace the lamp (fluro)) or to help me see in a dark corner). They
also have clear outers (not 'diffusers') and even a built in reflector
so I can get most of the light out and where I want it and being
designed for 'inspection' would probably take a knock or two without
damage. If I leave some slack cable on them they could be temporarily
re-positioned making use of the hook you often see on the ends of such
things?

http://www.machinemart.co.uk/images/...large/0231.jpg

Re the fluorescent, are there good and no_so_good, from an efficiency
pov please? Does spending more money generally mean I get a better
design (from a Lumens pov and ignoring the same unit priced higher
etc).

I did think of using a maintained lamp unit but they would be more
expensive and I don't necessarily want them on when the power is off
(and I don't think they would be easy to switch etc).

Any ideas welcomed. ;-)

Cheers, T i m

p.s. I guess I could use an inverter to run the existing 6' fluros off
a solar / mains charged battery but that might make the whole project
that much bigger and I'm not sure how efficient it would all be? This
all started from seeing one of those 15 quid solar shed lights! ;-)

[1] I have various solar panels (@~5W), can probably find an ex backup
type battery or two and have some suitable cable, so it's just the
actual lighting units I need.

On Oct 20, 1:08*pm, T i m wrote:
Hi All,

I would like to put some solar powered lights in the 20' x 10' x 8'
(to eaves) *workshop, mainly just to be able to see in there to move
about rather than work as such. I don't have power down there all the
time atm (long story) and even if I did (and in the spirit of d_i_y) I
still like the idea of 1) making use of some of this kit [1] and 2)
having some alternative lighting in there.

So, I don't mind having a few unit, say one on each of the 5 roof
trusses and a pull switch by the door to turn them on and off but what
is currently the most efficient and good vfm please, LED or CF /
Fluro?

CFL is most efficient, then linear fl. LEDs vary - theyre most useful
for very low light output devices, eg 1w. Ideal for low power drop
lights due to robustness.


12V inverted up to ~600V or regulated down to 5 etc?

Every change of voltage loses energy, so 12v will be most efficienct.


I was thinking those tubular 12V x 8W fluro inspection lamps
(typically a fiver) or LED equiv held under the beams by a couple of
Terry clips each (as that way they could be easily pulled down to
replace the lamp (fluro)) or to help me see in a dark corner). They
also have clear outers (not 'diffusers') and even a built in reflector
so I can get most of the light out and where I want it and being
designed for 'inspection' would probably take a knock or two without
damage. *If I leave some slack cable on them they could be temporarily
re-positioned making use of the hook you often see on the ends of such
things?

I'd probably use a couple of those for ceiling lights, and a droplight
or 2, maybe LED.


http://www.machinemart.co.uk/images/...large/0231.jpg

Re the fluorescent, are there good and no_so_good, from an efficiency
pov please?

there is significant variation. Very thin tube CFLs are some of the
best.

Does spending more money generally mean I get a better
design (from a Lumens pov and ignoring the same unit priced higher
etc).

Tesco microspirals are efficient and cheap. High CCT lamps are
slightly more efficient, but the light quality's nasty.


I did think of using a maintained lamp unit but they would be more
expensive and I don't necessarily want them on when the power is off
(and I don't think they would be easy to switch etc).

Any ideas welcomed. ;-)

Cheers, *T i m

p.s. I guess I could use an inverter to run the existing 6' fluros off
a solar / mains charged battery but that might make the whole project
that much bigger and I'm not sure how efficient it would all be? This
all started from seeing one of those 15 quid solar shed lights! ;-)

[1] I have various solar panels (@~5W), can probably find an ex backup
type battery or two and have some suitable cable, so it's just the
actual lighting units I need.

While you could run a 5 footer at 240v, it would take a real long time
to replenish the energy used at just 5w. Energy capture can be
improved a little with diffuse reflection in winter only - dont
concentrate in summer.

One option would be to run the 5 footer at much reduced power. Details
depend on the ballast type, but either way its easy to do. Tube life
would drop signifcantly, but tubes are so cheap and other methods not
so, so it may work well.

TBH though I'd not overlook gas lighting. Its way more reliable than
solar electric, needs no installation, gives sensible output levels.


NT

On Mon, 20 Oct 2008 06:07:23 -0700 (PDT), wrote:

So, I don't mind having a few unit, say one on each of the 5 roof
trusses and a pull switch by the door to turn them on and off but what
is currently the most efficient and good vfm please, LED or CF /
Fluro?

CFL is most efficient, then linear fl.

Ah, didn't know that.

LEDs vary - theyre most useful
for very low light output devices, eg 1w. Ideal for low power drop
lights due to robustness.

Ok ..


12V inverted up to ~600V or regulated down to 5 etc?

Every change of voltage loses energy, so 12v will be most efficienct.

That's what I was thinking but whilst I could probably (nearly) run
LED's directly from 12V DC (ie, no regulation wastage?) don't these
CFL's have inverters in them anyway?


I was thinking those tubular 12V x 8W fluro inspection lamps
(typically a fiver) or LED equiv held under the beams by a couple of
Terry clips each (as that way they could be easily pulled down to
replace the lamp (fluro)) or to help me see in a dark corner). They
also have clear outers (not 'diffusers') and even a built in reflector
so I can get most of the light out and where I want it and being
designed for 'inspection' would probably take a knock or two without
damage. *If I leave some slack cable on them they could be temporarily
re-positioned making use of the hook you often see on the ends of such
things?

I'd probably use a couple of those for ceiling lights, and a droplight
or 2, maybe LED.

Ok.


http://www.machinemart.co.uk/images/...large/0231.jpg

Re the fluorescent, are there good and no_so_good, from an efficiency
pov please?

there is significant variation. Very thin tube CFLs are some of the
best.

Ok ..

Does spending more money generally mean I get a better
design (from a Lumens pov and ignoring the same unit priced higher
etc).

Tesco microspirals are efficient and cheap.

I don't suppose they are available in 12V though? :-(

High CCT lamps are
slightly more efficient, but the light quality's nasty.

As long as they illuminate the area efficiently I'm not fussy. ;-)


snip

While you could run a 5 footer at 240v, it would take a real long time
to replenish the energy used at just 5w.

Understood.

Energy capture can be
improved a little with diffuse reflection in winter only - dont
concentrate in summer.

;-)

One option would be to run the 5 footer at much reduced power. Details
depend on the ballast type, but either way its easy to do. Tube life
would drop signifcantly, but tubes are so cheap and other methods not
so, so it may work well.

Hmm, I think I'll stick with an independent system then. 240V for real
/ working lighting and this solar for the odd time I pop down there
with the mains off (why is it the tool you need is where you aren't).

TBH though I'd not overlook gas lighting. Its way more reliable than
solar electric, needs no installation, gives sensible output levels.

Hmm, not sure about that (gas) .. sounds like the recipe for an
instant sun roof on my workshop!

All the best ..

T i m

p.s. Sorry but I'm getting old and my memory is failing fast ... did
we meet up once, solar panels and generators etc?

T i m wrote:
On Mon, 20 Oct 2008 06:07:23 -0700 (PDT), wrote:

So, I don't mind having a few unit, say one on each of the 5 roof
trusses and a pull switch by the door to turn them on and off but what
is currently the most efficient and good vfm please, LED or CF /
Fluro?
CFL is most efficient, then linear fl.

Ah, didn't know that.


AFAIK that is in fact not true.


That's what I was thinking but whilst I could probably (nearly) run
LED's directly from 12V DC (ie, no regulation wastage?) don't these
CFL's have inverters in them anyway?

Of course. One reason they are not very efficient.

Consider the typical 12v powered caravan fluorescent.

If you are using solar panels to charge car batteries, anyway.


Hmm, I think I'll stick with an independent system then. 240V for real
/ working lighting and this solar for the odd time I pop down there
with the mains off (why is it the tool you need is where you aren't).

Yes. I would simply have some batteries charged by solar if you must, or
by mains charger, and use caravan lights as emergency, and proper mains
tubes for real power.

On Mon, 20 Oct 2008 15:03:59 +0100, The Natural Philosopher
wrote:

That's what I was thinking but whilst I could probably (nearly) run
LED's directly from 12V DC (ie, no regulation wastage?) don't these
CFL's have inverters in them anyway?

Of course. One reason they are not very efficient.

Is this in general .. in comparison with incandescent (mind you, I
could do with some heating down there as well). ;-)

Consider the typical 12v powered caravan fluorescent.

I guess it's all relative. Lucky my eyes are still reasonable in the
dark and all I'm looking to do here is make it easier than stumbling
about in the pitch black or taking a torch.

If you are using solar panels to charge car batteries, anyway.

I have the panels and ex UPS batteries so I might as well have them
wired together and doing *something*?


Hmm, I think I'll stick with an independent system then. 240V for real
/ working lighting and this solar for the odd time I pop down there
with the mains off (why is it the tool you need is where you aren't).

Yes. I would simply have some batteries charged by solar if you must, or
by mains charger, and use caravan lights as emergency, and proper mains
tubes for real power.

Well, there are currently 6 x 5' (not 6') singles down there and
supplementary light over the bench and an Angle poise with mini spot
over the lathe. I could leave an auto charger on there as well cos if
the solar panels do their job there won't be much for the mains
charger to do when the power is on?

Cheers, T i m

On Oct 20, 3:03*pm, The Natural Philosopher wrote:
T i m wrote:
On Mon, 20 Oct 2008 06:07:23 -0700 (PDT), wrote:

So, I don't mind having a few unit, say one on each of the 5 roof
trusses and a pull switch by the door to turn them on and off but what
is currently the most efficient and good vfm please, LED or CF /
Fluro?
CFL is most efficient, then linear fl.

Ah, didn't know that.

AFAIK that is in fact not true.

Both technologies cover a range of efficiencies, so best to look at
individual ones if you want exact figures.


NT

wrote:
On Oct 20, 3:03 pm, The Natural Philosopher wrote:
T i m wrote:
On Mon, 20 Oct 2008 06:07:23 -0700 (PDT), wrote:
So, I don't mind having a few unit, say one on each of the 5 roof
trusses and a pull switch by the door to turn them on and off but what
is currently the most efficient and good vfm please, LED or CF /
Fluro?
CFL is most efficient, then linear fl.
Ah, didn't know that.
AFAIK that is in fact not true.

Both technologies cover a range of efficiencies, so best to look at
individual ones if you want exact figures.



Indeed. But AFAIK the figures are roughly 10-25% efficient for linear
fluorescents. 6-10% for CFL, similar for LED and 1-3% efficient for
incandescent.

This makes reasonable reading.

http://en.wikipedia.org/wiki/Luminous_efficacy

A CFL bulb is merely a normal fluorescent with all the efficiency
compromised by a cheap and nasty inverter, a shortened and coiled tube,
and use of natural light phosphors to make it 'look' nicer.

Industrial grade striplights with electronic ballasts compromise light
quality to get efficiency.


NT

On Oct 20, 3:03*pm, The Natural Philosopher wrote:
T i m wrote:
On Mon, 20 Oct 2008 06:07:23 -0700 (PDT), wrote:

So, I don't mind having a few unit, say one on each of the 5 roof
trusses and a pull switch by the door to turn them on and off but what
is currently the most efficient and good vfm please, LED or CF /
Fluro?
CFL is most efficient, then linear fl.

Ah, didn't know that.

AFAIK that is in fact not true.

Both technologies cover a range of efficiencies, so best to look at
individual ones if you want exact figures.


That's what I was thinking but whilst I could probably (nearly) run
LED's directly from 12V DC (ie, no regulation wastage?)

You need regulation for that, unless you want to run them with a very
inefficient ballast. A constant current regulator is good, ideally an
LDO type.


don't these
CFL's have inverters in them anyway?

Of course. One reason they are not very efficient.

CFL and linear FL are the 2 most efficient domestic white light
sources.


NT

wrote:


don't these
CFL's have inverters in them anyway?

Of course. One reason they are not very efficient.

CFL and linear FL are the 2 most efficient domestic white light
sources.



That right, but CFLS are not as efficient as linear.

From experience, the caravan type linear fluorescent is probably the
best thing from a 12v source, though some LEDS seem to be catching up fast.

To got from DC to inverted AC, then to a mains CFL, and then back to DC
and to AC again in the bulb is madness.



NT

On Oct 20, 2:52*pm, T i m wrote:
On Mon, 20 Oct 2008 06:07:23 -0700 (PDT), wrote:

12V inverted up to ~600V or regulated down to 5 etc?

Every change of voltage loses energy, so 12v will be most efficienct.

That's what I was thinking but whilst I could probably (nearly) run
LED's directly from 12V DC (ie, no regulation wastage?) don't these
CFL's have inverters in them anyway?

Yes, but of a different type to the one's you'd use externally. Ever
voltage conversion step loses energy, so the less steps you add the
better from an effieicncy POV. Of course most efficient isn't always
cheapest - 240v CFLs cost less than 12v ones.


Tesco microspirals are efficient and cheap.

I don't suppose they are available in 12V though? :-(

I guess not


High CCT lamps are
slightly more efficient, but the light quality's nasty.

As long as they illuminate the area efficiently I'm not fussy. ;-)

ok


While you could run a 5 footer at 240v, it would take a real long time
to replenish the energy used at just 5w.

Understood.

Then again if you only use it occasionally, and you've got more than
one 5w panel and a battery big enough to supply it for as long as you
use it, it would be ok. If.


TBH though I'd not overlook gas lighting. Its way more reliable than
solar electric, needs no installation, gives sensible output levels.

Hmm, not sure about that (gas) .. sounds like the recipe for an
instant sun roof on my workshop!

ha - they do produce a lot of heat.


p.s. Sorry but I'm getting old and my memory is failing fast ... did
we meet up once, solar panels and generators etc?

Sorry, I've not been to any of the ukdiy meets yet, so I dont think
so. Been to other events though, if that's what you mean.


NT

On Mon, 20 Oct 2008 16:51:38 -0700 (PDT), wrote:

On Oct 20, 2:52*pm, T i m wrote:
On Mon, 20 Oct 2008 06:07:23 -0700 (PDT), wrote:

12V inverted up to ~600V or regulated down to 5 etc?

Every change of voltage loses energy, so 12v will be most efficienct.

That's what I was thinking but whilst I could probably (nearly) run
LED's directly from 12V DC (ie, no regulation wastage?) don't these
CFL's have inverters in them anyway?

Yes, but of a different type to the one's you'd use externally.

So better or worse than the external ones do we think? I mean the
external ones are much bigger and what must be built in so and I
presume they wouldn't do that less they had to (bigger / heavier might
be better but more expensive)?

Ever
voltage conversion step loses energy, so the less steps you add the
better from an effieicncy POV.

Agreed. I was thinking that the nearer I could get to a (say) raw 12V
as a ideal supply the less regulation I might need? However, you often
deed a bit of an offset for active regulation so maybe I'd end up
looking for a 9V supply rail for the LED's? With yer std LM7809 type
regulators does that mean the surplus energy is going to be 'wasted'
in the reg?

Of course most efficient isn't always
cheapest - 240v CFLs cost less than 12v ones.

By quite a percentage it seems. :-(


Tesco microspirals are efficient and cheap.

I don't suppose they are available in 12V though? :-(

I guess not

I have since found quite a few suppliers of 12V CFL's and it seems
they may be the preferred solution for remote buildings, stables and
sheds etc. ie, You can get kits with panel, battery and a couple of lv
CFL's.

While you could run a 5 footer at 240v, it would take a real long time
to replenish the energy used at just 5w.

Understood.

Then again if you only use it occasionally, and you've got more than
one 5w panel and a battery big enough to supply it for as long as you
use it, it would be ok. If.

Indeed, and that may well be the actual scenario / usage pattern.

As an aside I've just bought a couple of ~1.5W 12V (not 12V but higher
of course) bare panels with the intention of making them up into fully
waterproof modules to fix the South facing wall of this house, where
it happens we park a couple of our motorbikes. A suitable non-latching
connector fitted in the right place on the bikes and the panels should
at least balance any background losses from alarms, and maybe even
keep them topped up and ready.

I think there could be a market for a long, narrow 12V 'charging'
panel that could be fitted on or on the wall underneath external
window sills. Not the ideal angle(s) maybe but probably better than
nothing and not 'obvious' to passers by?


TBH though I'd not overlook gas lighting. Its way more reliable than
solar electric, needs no installation, gives sensible output levels.

Hmm, not sure about that (gas) .. sounds like the recipe for an
instant sun roof on my workshop!

ha - they do produce a lot of heat.

I was thinking more the mixture of gas and air and a lighted match!


p.s. Sorry but I'm getting old and my memory is failing fast ... did
we meet up once, solar panels and generators etc?

Sorry, I've not been to any of the ukdiy meets yet, so I dont think
so. Been to other events though, if that's what you mean.

I was thinking I may have been to yours, a few years back but I must
have my wires crossed (sorry).

Cheers, T i m

On Oct 21, 9:13*am, T i m wrote:
On Mon, 20 Oct 2008 16:51:38 -0700 (PDT), wrote:
On Oct 20, 2:52*pm, T i m wrote:
On Mon, 20 Oct 2008 06:07:23 -0700 (PDT), wrote:

12V inverted up to ~600V or regulated down to 5 etc?

Every change of voltage loses energy, so 12v will be most efficienct.

That's what I was thinking but whilst I could probably (nearly) run
LED's directly from 12V DC (ie, no regulation wastage?) don't these
CFL's have inverters in them anyway?

Yes, but of a different type to the one's you'd use externally.

So better or worse than the external ones do we think? I mean the
external ones are much bigger and what must be built in so and I
presume they wouldn't do that less they had to (bigger / heavier might
be better but more expensive)?

They're really 2 fairly different things. Efficiency and life
expectancy vary a fair bit for both types.


Ever
voltage conversion step loses energy, so the less steps you add the
better from an effieicncy POV.

Agreed. I was thinking that the nearer I could get to a (say) raw 12V
as a ideal supply the less regulation I might need?

If youre thinking of LEDs here, its the other way round. The closer
your LED string is to 10.4v (cutoff voltage for 12v lead acids), with
an unregulated ballast the more the LED current varies as the battery
varies from 10.4v to 14v. Say we have a 10v LED string, then the
ballast drops anything from 0.4v to 4.4v, current changing by a factor
of 11, which is quite useless.

If you want efficiency, you need to use a regulator as an LED ballast.


However, you often
deed a bit of an offset for active regulation so maybe I'd end up
looking for a 9V supply rail for the LED's? With yer std LM7809 type
regulators does that mean the surplus energy is going to be 'wasted'
in the reg?

Whats dropped in the reg is wasted, yes. But you cant use a 7809 as 78
series require a min Vdrop of 4v, and 10.4v - 6v = 4.4v max for your
LED string, with consequent poor efficiency. Best to use an LDO reg
(Low DropOut) in constant current mode, then you can go upto 10v or
more with your LED string.

If you went with a switched mode reg, then the dropped V wouldnt be
wasted, but for LEDs the cost & complication isnt generally worth it.
OTOH if you know how to easily make a basic sm reg it would likely be
practical.


While you could run a 5 footer at 240v, it would take a real long time
to replenish the energy used at just 5w.

Understood.

Then again if you only use it occasionally, and you've got more than
one 5w panel and a battery big enough to supply it for as long as you
use it, it would be ok. If.

Indeed, and that may well be the actual scenario / usage pattern.

Would save you buying anything but an invertor & changeover relay.

Then again if you've got mains you dont need the panels.


As an aside I've just bought a couple of ~1.5W 12V (not 12V but higher
of course) bare panels with the intention of making them up into fully
waterproof modules to fix the South facing wall of this house, where
it happens we park a couple of our motorbikes. A suitable non-latching
connector fitted in the right place on the bikes and the panels should
at least balance any background losses from alarms, and maybe even
keep them topped up and ready.

Maybe in summer. Are they going flat?


I think there could be a market for a long, narrow 12V 'charging'
panel that could be fitted on or on the wall underneath external
window sills. Not the ideal angle(s) maybe but probably better than
nothing and not 'obvious' to passers by?

I'm not sure a PV solar panel is that useful whre there's already
mains.


TBH though I'd not overlook gas lighting. Its way more reliable than
solar electric, needs no installation, gives sensible output levels.

Hmm, not sure about that (gas) .. sounds like the recipe for an
instant sun roof on my workshop!

ha - they do produce a lot of heat.

I was thinking more the mixture of gas and air and a lighted match!

Who would leave it on unlit?


p.s. Sorry but I'm getting old and my memory is failing fast ... did
we meet up once, solar panels and generators etc?

Sorry, I've not been to any of the ukdiy meets yet, so I dont think
so. Been to other events though, if that's what you mean.

I was thinking I may have been to yours, a few years back but I must
have my wires crossed (sorry).

Cheers, T i m

Ah, yeah must be someone else then


NT

T i m wrote:


Agreed. I was thinking that the nearer I could get to a (say) raw 12V
as a ideal supply the less regulation I might need? However, you often
deed a bit of an offset for active regulation so maybe I'd end up
looking for a 9V supply rail for the LED's? With yer std LM7809 type
regulators does that mean the surplus energy is going to be 'wasted'
in the reg?

LEDS of the silicon/gallium sort have typical forward voltages in the
1-3v region.

They need to be current driven. the cheap and cheerful wy is to bung in
a power wasting resistor. The better way is a SMPS that detects the
current and adjusts output accordingly. Essentially chop te DC to AC and
put an inductor in series to limit current losslessly - well fairly
losslesly anyway.

7809 is not what you want at all.



Of course most efficient isn't always
cheapest - 240v CFLs cost less than 12v ones.

By quite a percentage it seems. :-(

Econmomies of scale. If you have a large office or industrial space to
illuminate, you use ****loads of striplights. They are the most
efficient, and because they are produced in ****loads, they are cheap.

The mini ones are just as hard, if not harder, to make, and have
slightly more complex electronics. And probably slightly less efficient
electronics. And are sold in much smaller quantities for boat and
caravan type usage.



I have since found quite a few suppliers of 12V CFL's and it seems
they may be the preferred solution for remote buildings, stables and
sheds etc. ie, You can get kits with panel, battery and a couple of lv
CFL's.

Yup. I've got about 4 such in my camper van. No battery though. Just a
12v capable mini fluorescent pair with the inverters. YOu can in fact
get fluorescent torches as well.




While you could run a 5 footer at 240v, it would take a real long time
to replenish the energy used at just 5w.
Understood.

Really?. I don't understand at all. 5W is 5W irrespective of the voltage.


Then again if you only use it occasionally, and you've got more than
one 5w panel and a battery big enough to supply it for as long as you
use it, it would be ok. If.

Indeed, and that may well be the actual scenario / usage pattern.

I can run a couple of 12v fluoros, an occasional water pump, off a
nearly fsked leisure battery for a couple of LONG evenings before it
goes flat.

Many people with boats use solar panels to charge leisure batteries, and
run without mains of generator power at all.

Its not hugely efficient, nor is it cheap, but if te biats engine isn;
running, its reasonable compromise.



As an aside I've just bought a couple of ~1.5W 12V (not 12V but higher
of course) bare panels with the intention of making them up into fully
waterproof modules to fix the South facing wall of this house, where
it happens we park a couple of our motorbikes. A suitable non-latching
connector fitted in the right place on the bikes and the panels should
at least balance any background losses from alarms, and maybe even
keep them topped up and ready.

I think there could be a market for a long, narrow 12V 'charging'
panel that could be fitted on or on the wall underneath external
window sills. Not the ideal angle(s) maybe but probably better than
nothing and not 'obvious' to passers by?

Again, look at the caravan market. My caper has a mains to 12v SMPS
charger that is very compact and very efficient. Not weatherproof, but
that is simply a question of the right enclosure.

Meow is as usual disseminating a mixture, of truths, half truths and
mieleading stuff improperly understood.

If you want to go into a solar/leisure battery/12v lighting system,with
or without mains backup, go and find a caravan or boat specialist
suppliers. Everything you need will be there.

using an inverter to the run stuff intended for mains is a dubious path:
If you want to go THAT route, use a computer UPS - they will run a
complete mains installation from batteries for a period.

And then use proper full length striplights, not CFLs.

On Mon, 20 Oct 2008 06:07:23 -0700 (PDT), wrote:
On Oct 20, 1:08*pm, T i m wrote:
Hi All,

I would like to put some solar powered lights in the 20' x 10' x 8'
(to eaves) *workshop, mainly just to be able to see in there to move
about rather than work as such. I don't have power down there all the
time atm (long story) and even if I did (and in the spirit of d_i_y) I
still like the idea of 1) making use of some of this kit [1] and 2)
having some alternative lighting in there.

So, I don't mind having a few unit, say one on each of the 5 roof
trusses and a pull switch by the door to turn them on and off but what
is currently the most efficient and good vfm please, LED or CF /
Fluro?

CFL is most efficient, then linear fl. LEDs vary - theyre most useful
for very low light output devices, eg 1w. Ideal for low power drop
lights due to robustness.

If you fancy playing around with some LEDs, try these kinda things:
http://tinyurl.com/5psh64
Briefly, high-power LEDs are extremely bright. These units claim up to
400 lumems (c.f. 100W bulb: 1700 lumens) and can be wired in series
to match the voltage from your battery - more or less.
The one's I got a couple of years ago were 1W jobs, they came with a
warning not to look directly at the light source. Although not as
bright as a mains bulb, the source is much, much smaller so the light
is more concentrated.

On 20 Oct 2008 14:48:16 GMT, pete wrote:


If you fancy playing around with some LEDs, try these kinda things:
http://tinyurl.com/5psh64
Briefly, high-power LEDs are extremely bright. These units claim up to
400 lumems (c.f. 100W bulb: 1700 lumens) and can be wired in series
to match the voltage from your battery - more or less.

Understood.

The one's I got a couple of years ago were 1W jobs, they came with a
warning not to look directly at the light source. Although not as
bright as a mains bulb, the source is much, much smaller so the light
is more concentrated.

Yes, I have a single_LED torch and it is very intense indeed!

If it's agreed that LED's are the most efficient I'm thinking I could
wire a few of those little 'stick-up' lights (that normally take 3 x
AAA or similar) together in series parallel (if each unit is designed
to run on 3 x 1.5V (4.5V) then 3 in series should be ok on ~14V ?

I've seen said pretty cheap on the markets and I think are often also
magnetic (so would clip directly to my steel roof angles). ;-)

http://www.amazon.co.uk/LED-Stick-N-.../dp/B000NOSCYO

With enough it will look like those halogen downlighters that people
were so keen on before they became too expensive to run. ;-)

Cheers, T i m

On Oct 20, 6:37*pm, T i m wrote:
On 20 Oct 2008 14:48:16 GMT, pete wrote:



If you fancy playing around with some LEDs, try these kinda things:
http://tinyurl.com/5psh64
Briefly, high-power LEDs are extremely bright. These units claim up to
400 lumems (c.f. 100W bulb: 1700 lumens) and can be wired in series
to match the voltage from your battery - more or less.

Understood.

The one's I got a couple of years ago were 1W jobs, they came with a
warning not to look directly at the light source. Although not as
bright as a mains bulb, the source is much, much smaller so the light
is more concentrated.

Yes, I have a single_LED torch and it is very intense indeed!

If it's agreed that LED's are the most efficient I'm thinking I could
wire a few of those little 'stick-up' lights (that normally take 3 x
AAA or similar) together in series parallel (if *each unit is designed
to run on 3 x 1.5V (4.5V) then 3 in series should be ok on ~14V ?

I've seen said pretty cheap on the markets and I think are often also
magnetic (so would clip directly to my steel roof angles). ;-)

http://www.amazon.co.uk/LED-Stick-N-.../dp/B000NOSCYO

I'd be surprised if those were the most efficient LEDs around. More
likely cheap sh--.


NT

On Tue, 21 Oct 2008 17:07:29 -0700 (PDT), wrote:


I've seen said pretty cheap on the markets and I think are often also
magnetic (so would clip directly to my steel roof angles). ;-)

http://www.amazon.co.uk/LED-Stick-N-.../dp/B000NOSCYO

I'd be surprised if those were the most efficient LEDs around. More
likely cheap sh--.

Well, good point and one I'd considered but I guess these things are
relative. Also, I considered that 'several' cheap / (potentially not
the best efficiency in the world) lights might just do the intended
job better than something less 'affordable'?

I've got a few of such LED lights already but more designed for
portable / car use (they have a magnet on the back) and yesterday I
tried one in the darkened kitchen. As expected the LED's are fairly
directional giving me a bright downlighter / spot but still the one
lamp was more than sufficient to take a dangerous dark hole into
somewhere you could safely make a cuppa. ;-)

Given that this lamp has so far lasted *ages* of 3 x cheapo AAA cells
I think it would be ok as part of my experiment. [1]

Cheers, T i m

[1] I will first get 3 off these and run them from 12V and measure the
current. I will then compare those with one fluro inspection strip
lamp, a 12V cfl and a 'caravan' type fluro.

In article ,
writes:
CFL is most efficient, then linear fl.

Other way around.
The extra losses in a CFL are caused by folding the tube,
so there's always one bit of tube blocking the light from
another bit of tube, and the tubes are quite opaque so that
this light is almost completely lost. Some effort went into
working out ways of folding the tube so as to lose least light
(and give a reasonably uniform light distribution). An open
coil/spiral is generally the winner, but results in lamps
which are too big for many purposes (and I believe there are
patent issues with it too). Trying to make a small compact
light source from a tube is always the loser.

With a linear tube, there is no self shielding of the tube.

In both cases, the luminare also plays a big part -- i.e.
how well it directs the light where it is wanted and avoids
losing/wasting it elsewhere, and in the case of luminares
of a certain age, the efficiency of external control gear.
(There's a period, probably from around 1985 to 2000, when
control gear efficiencies got lower and lower until EU
stepped in and set minimum legal standards.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel wrote:
In article ,
writes:
CFL is most efficient, then linear fl.

Other way around.
The extra losses in a CFL are caused by folding the tube,
so there's always one bit of tube blocking the light from
another bit of tube, and the tubes are quite opaque so that
this light is almost completely lost. Some effort went into
working out ways of folding the tube so as to lose least light
(and give a reasonably uniform light distribution). An open
coil/spiral is generally the winner, but results in lamps
which are too big for many purposes (and I believe there are
patent issues with it too). Trying to make a small compact
light source from a tube is always the loser.



The best/brightest CFLs we have are described as being 'trumpet' style.
An open spiral similar in shape to a trumpet mute. On that basis, my
experience agrees absolutely. (Also happen to have excellent colour.)

--
Rod

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