Smart 1 watt LED front light

On Thu, 2 Dec 2004 01:36:29 +0000 (UTC), [email hidden] (Chris

Malcolm) said:

Up till now I've used a rather feeble white LED front light for being
seen and being legal, with a 2.5 watt halogen lamp for when I needed
to see where I was going. I've been waiting for the 1 watt Luxeon
white LED to appear in a good cheap bike light design.

Found an attractively cheap one, the Smart 1 watt white LED
lamp.

Thanks for the info. Can you confirm which model you are describing? I
can see a couple of Smart single LED lamps at Wiggle, one of them is
only £12.99, so I'm assuming this is yours:

http://www.wiggle.co.uk/v2_product_detail.asp?ProdID=5360014731

--

Call me "Bob"

"More oneness, less categories,
Open hearts, no strategies"

Email address is spam trapped, to reply directly remove the beverage.

Call me Bob said:

On Thu, 2 Dec 2004 01:36:29 +0000 (UTC), [email hidden] (Chris
Malcolm) wrote:

Quoted message said:

Quoted message said:

Up till now I've used a rather feeble white LED front light for being
seen and being legal, with a 2.5 watt halogen lamp for when I needed
to see where I was going. I've been waiting for the 1 watt Luxeon
white LED to appear in a good cheap bike light design.

Found an attractively cheap one, the Smart 1 watt white LED
lamp.

Quoted message said:

Thanks for the info. Can you confirm which model you are describing? I
can see a couple of Smart single LED lamps at Wiggle, one of them is
only #12.99, so I'm assuming this is yours:

Quoted message said:

http://www.wiggle.co.uk/v2_product_detail.asp?ProdID=5360014731

That's it. You may be able to get it a bit cheaper. I got mine for
approx 25 quid from The Bike Chain in Edinburgh on a special 10% off
just-opened-shop offer. It comes with batteries included.

There's an apparently identical lamp (same photo, same advertising)
sold in the US under another name (which I forget).

--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

Chris Malcolm said:

There's an apparently identical lamp (same photo, same advertising)
sold in the US under another name (which I forget).

Planet Bike. I've got a couple bought over there befor the Smart
version became available over here

Tony

i'd be very interested in this if it is regulated - any chance you
could measure current at various voltages to confirm? Or let us know
how bright it stays as the batteries wear down?

cheers,

rob.

[email hidden] (Chris Malcolm) wrote in message news:<[email hidden]>...

Quoted message said:

Up till now I've used a rather feeble white LED front light for being
seen and being legal, with a 2.5 watt halogen lamp for when I needed
to see where I was going. I've been waiting for the 1 watt Luxeon
white LED to appear in a good cheap bike light design.

Found an attractively cheap one, the Smart 1 watt white LED
lamp. Doesn't say it's a Luxeon 1 watt LED, but if it isn't it looks
and performs like one. Runs off 4 AAs. Says on the packet "only use AA
alkalines", which suggests lack of proper regulation, but trying it
with batteries in various states of exhaustion suggests it is in fact
regulated. The important point is that it has no significant
difference in brightness of light or current drawn when used with
freshly charged NiMH AAs, so it is clearly safe to use them.

Compared to the Cateye 1 watt LED, it has a much wider close beam,
making it suitable for riding in woods at night, and better for being
seen. The long beam doesn't reach as far as the Cateye. Some suggest
that combining this with the Cateye makes a perfect combination for
high speed night riding on unlit roads.

Seems to put out about as much light as a 2.5 watt halogen lamp. Being
a slow rider I've always found that adequate if the beam shape was
good. The LED light should give at least twice the battery life plus
the very long graceful degradation of low power LED light on low
batteries compared to the rapid death of filament bulbs.

"Chris Malcolm" <[email hidden]> wrote

Quoted message said:

Up till now I've used a rather feeble white LED front light for being
seen and being legal, with a 2.5 watt halogen lamp for when I needed
to see where I was going. I've been waiting for the 1 watt Luxeon
white LED to appear in a good cheap bike light design.

Found an attractively cheap one, the Smart 1 watt white LED
lamp. Doesn't say it's a Luxeon 1 watt LED, but if it isn't it looks
and performs like one. Runs off 4 AAs. Says on the packet "only use AA
alkalines", which suggests lack of proper regulation, but trying it
with batteries in various states of exhaustion suggests it is in fact
regulated. The important point is that it has no significant
difference in brightness of light or current drawn when used with
freshly charged NiMH AAs, so it is clearly safe to use them.

The curious thing concerns the run time where 30 hours is claimed. Duracell
AA's have a capacity of about 2Ahr which implies a current of 70mA. Say the
batteries give 5V, that's only 0.35W.

Presumably the run time is really only 8 hours with 22 hours as a glow
worm. What is your expereince?

i just measured a smart Polaris 2AA front LED - a nice little lamp,
very neat. The blurb mentioned 'Smart Peak Voltage Technology' - I
wondered if this meant regulation. However:
2.8V 138mA fresh alkalines
2.5V 72mA fresh NiMH / part used alkaline
2.42V 53mA zinc carbon
2.18V 39mA old alkalines
suggests not. A shame - it's great with fresh batteries.

[email hidden] (robc) wrote in message news:<[email hidden]>...

Quoted message said:

i'd be very interested in this if it is regulated - any chance you
could measure current at various voltages to confirm? Or let us know
how bright it stays as the batteries wear down?

cheers,

rob.

[email hidden] (Chris Malcolm) wrote in message news:<[email hidden]>...

Quoted message said:

Up till now I've used a rather feeble white LED front light for being
seen and being legal, with a 2.5 watt halogen lamp for when I needed
to see where I was going. I've been waiting for the 1 watt Luxeon
white LED to appear in a good cheap bike light design.

Found an attractively cheap one, the Smart 1 watt white LED
lamp. Doesn't say it's a Luxeon 1 watt LED, but if it isn't it looks
and performs like one. Runs off 4 AAs. Says on the packet "only use AA
alkalines", which suggests lack of proper regulation, but trying it
with batteries in various states of exhaustion suggests it is in fact
regulated. The important point is that it has no significant
difference in brightness of light or current drawn when used with
freshly charged NiMH AAs, so it is clearly safe to use them.

Compared to the Cateye 1 watt LED, it has a much wider close beam,
making it suitable for riding in woods at night, and better for being
seen. The long beam doesn't reach as far as the Cateye. Some suggest
that combining this with the Cateye makes a perfect combination for
high speed night riding on unlit roads.

Seems to put out about as much light as a 2.5 watt halogen lamp. Being
a slow rider I've always found that adequate if the beam shape was
good. The LED light should give at least twice the battery life plus
the very long graceful degradation of low power LED light on low
batteries compared to the rapid death of filament bulbs.

(robc) said:

i'd be very interested in this if it is regulated - any chance you
could measure current at various voltages to confirm? Or let us know
how bright it stays as the batteries wear down?

Quoted message said:

[email hidden] (Chris Malcolm) wrote in message news:<[email hidden]>...

Quoted message said:

Quoted message said:

Says on the packet "only use AA
alkalines", which suggests lack of proper regulation, but trying it
with batteries in various states of exhaustion suggests it is in fact
regulated. The important point is that it has no significant
difference in brightness of light or current drawn when used with
freshly charged NiMH AAs, so it is clearly safe to use them.

I did measure the voltage across a volt meter interpolated between the
battery and casing when the light was switched on. but obviously
drawing only voltmeter current: 4.1 volts, when the actually battery
voltage was 6.12 (new alkalines) or only 5 (not quite fresh
NiMhs). That, and the above, convince me it is regulated.

I'm not planning any more experiments. You'll have to wait at least a
few weeks for my observations on battery exhaustion :-)
--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

DavidR' nospam_a@t_nospam.com said:

"Chris Malcolm" <[email hidden]> wrote

Quoted message said:

Quoted message said:

Up till now I've used a rather feeble white LED front light for being
seen and being legal, with a 2.5 watt halogen lamp for when I needed
to see where I was going. I've been waiting for the 1 watt Luxeon
white LED to appear in a good cheap bike light design.

Found an attractively cheap one, the Smart 1 watt white LED
lamp.

Quoted message said:

The curious thing concerns the run time where 30 hours is claimed. Duracell
AA's have a capacity of about 2Ahr which implies a current of 70mA. Say the
batteries give 5V, that's only 0.35W.

Quoted message said:

Presumably the run time is really only 8 hours with 22 hours as a glow
worm.

Yup, that was what I guessed as well. I have an experiment I use to
assess the total light output of a lamp: I shine at the white ceiling
of a darkened room, and measure the illumination of a bit of white
paper on a table with a light meter. It produces the same total light
output as a hand torch I have which also uses a 1 watt Luxeon, but
with only 3AAs. The total light output appears to be the same. Of
course they might both be running at .75 watts for all I know, but it
does suggest they're both sticking the same design criteria for
running the LED.

Quoted message said:

What is your expereince?

I can confirm that putting seriously dead batteries in it produces a
glow worm light, and not quite so dead ones produce an enthusiastic
glow worm. Unless it behaves unexpectedly, or I get very bored, I'll
probably not do any more detailed experiments.

--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

"Chris Malcolm" <[email hidden]> wrote

Quoted message said:

DavidR' nospam_a@t_nospam.com said:

"Chris Malcolm" <[email hidden]> wrote

Quoted message said:

Quoted message said:

Presumably the run time is really only 8 hours with 22 hours as a glow
worm.

Yup, that was what I guessed as well. I have an experiment I use to
assess the total light output of a lamp: I shine at the white ceiling
of a darkened room, and measure the illumination of a bit of white
paper on a table with a light meter. It produces the same total light
output as a hand torch I have which also uses a 1 watt Luxeon, but
with only 3AAs. The total light output appears to be the same. Of
course they might both be running at .75 watts for all I know, but it
does suggest they're both sticking the same design criteria for
running the LED.

Quoted message said:

What is your expereince?

I can confirm that putting seriously dead batteries in it produces a
glow worm light, and not quite so dead ones produce an enthusiastic
glow worm. Unless it behaves unexpectedly, or I get very bored, I'll
probably not do any more detailed experiments.

I just bought a Cateye EL-120 just for a notice light. This has a single
led and uses 2 AA's so *must* have a boost circuit to work. The current
drawn is

Fresh alkalines 60mA
NiMh 30mA

Since the power & storage element is the most expensive part of a booster,
it is difficult to imagine penny pinching being the reason for not
regulating it. I wonder what the real reason is. It works remarkably well
when overdriven by fresh batteries though.

Actually this brings other thoughts into play: leds are fine for low power
operation but aren't we getting carried away with ones intended to
illuminate the road?

A 2.4W filament lamp costs about £12. Put NiMh batteries in it and it gives
4 hours operation. A 1W led lamp, costing £26 gives less output for 8
hours. It's not cost effective. The argument that a led gives longer life
doen't hold water either because I end up breaking the things long before
the bulb gives up.

Why not a flourescent lamp? Most such torches only drive their 4W tubes to
about 1.5W; with proper drive and focussing they ought to be pretty
effective potentially.

DavidR' nospam_a@t_nospam.com said:

I just bought a Cateye EL-120 just for a notice light. This has a single
led and uses 2 AA's so *must* have a boost circuit to work. The current
drawn is

Quoted message said:

Fresh alkalines 60mA
NiMh 30mA

Quoted message said:

Since the power & storage element is the most expensive part of a booster,
it is difficult to imagine penny pinching being the reason for not
regulating it. I wonder what the real reason is. It works remarkably well
when overdriven by fresh batteries though.

You underestimate how easily penny-pinching accountants can make
nonsense of a good engineering design!

Quoted message said:

Actually this brings other thoughts into play: leds are fine for low power
operation but aren't we getting carried away with ones intended to
illuminate the road?

Quoted message said:

A 2.4W filament lamp costs about #12. Put NiMh batteries in it and it gives
4 hours operation. A 1W led lamp, costing #26 gives less output for 8
hours.

I'm not sure about that. My previous bike lamp was a 2.4W filament
type, which I was quite happy with, and it was the standard of
lighting which I was waiting LED front lights to catch up with before
I bought one. It's hard to say which puts out most light with fresh
batteries, or which lights up the road better, because the beam shapes
and colour temperature are so different. I suspect the filament light
has a slight edge. But with half used batteries, the filament lamp is
noticeably weaker, whereas the Smart is still as bright as new. I'd
say it's definitely a viable replacement.

Quoted message said:

It's not cost effective. The argument that a led gives longer life
doen't hold water either because I end up breaking the things long before
the bulb gives up.

In terms of resistance to breakage, my twice-the-price Smart is much
more robustly engineered. It also doesn't get switched on in my bag!
With an hour's dark commuting not unusual at this time of year, the
extra battery life is a pleasant convenience, and the long graceful
degradation of light output once the batteries start to die means that
I don't have to carry spares.

Quoted message said:

Why not a flourescent lamp? Most such torches only drive their 4W tubes to
about 1.5W; with proper drive and focussing they ought to be pretty
effective potentially.

That's the big problem: focussing a fluorescent tube.
--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

DavidR nospam_a@t_nospam.com opined the following...

Quoted message said:

I just bought a Cateye EL-120 just for a notice light. This has a single
led and uses 2 AA's so *must* have a boost circuit to work. The current
drawn is

Fresh alkalines 60mA
NiMh 30mA

Why must it have a boost circuit. 2.4v - 3v is enough for some LEDs.

Quoted message said:

Actually this brings other thoughts into play: leds are fine for low power
operation but aren't we getting carried away with ones intended to
illuminate the road?

Not really.

Quoted message said:

A 2.4W filament lamp costs about £12. Put NiMh batteries in it and it gives
4 hours operation. A 1W led lamp, costing £26 gives less output for 8
hours. It's not cost effective. The argument that a led gives longer life
doen't hold water either because I end up breaking the things long before
the bulb gives up.

OK. A 1W led (The base unit including lens) costs £12. Some regulation
circuitry can be built for a fiver or less, depending on how efficient
you want it.

It's hard to directly compare them as the filament lamp often requires a
higher voltage and the actual current draw differs from unit to unit.

I'm currently running a 3W led at just over half-current (These appear
to have a non-linear response to current increases) and it is bright
enough to cause cars to dip their headlights when out on country roads.
I plan to modify the circuit so that it is switchable to full current as
it currently limits the speeds I can do when out in "real" darkness.

I had two bulbs die in my former light before the light itself died. The
replacements cost be around £5 each. The light died because I built a
particularly [censored] mounting bracket for it, out of copper strips and it
fell off and got run over.

Quoted message said:

Why not a flourescent lamp? Most such torches only drive their 4W tubes to
about 1.5W; with proper drive and focussing they ought to be pretty
effective potentially.

Because it's a royal PITA to focus a flourescent lamp.

Jon

On 6/12/04 10:50 am, in article [email hidden],

Jon Senior' jon_AT_restlesslemon_DOTco_DOT_uk said:

I'm currently running a 3W led at just over half-current (These appear
to have a non-linear response to current increases) and it is bright
enough to cause cars to dip their headlights when out on country roads.
I plan to modify the circuit so that it is switchable to full current as
it currently limits the speeds I can do when out in "real" darkness.

Would it be possible to bodge something like that into a MR16/MR11 format?
The reason I ask is that it would be very nice to replace one of the halogen
lamps on my dual lamp setups..

...d

David Martin [email hidden] opined the following...

Quoted message said:

Would it be possible to bodge something like that into a MR16/MR11 format?
The reason I ask is that it would be very nice to replace one of the halogen
lamps on my dual lamp setups..

Yes. A 3W with lens is about the same size as an MR11 (I think). The
control circuitry is pretty small but could easily be made external.

Jon

"Jon Senior" <jon_AT_restlesslemon_DOTco_DOT_uk> wrote

Quoted message said:

DavidR nospam_a@t_nospam.com opined the following...

Quoted message said:

Quoted message said:

I just bought a Cateye EL-120 just for a notice light. This has a single
led and uses 2 AA's so *must* have a boost circuit to work. The current
drawn is

Quoted message said:

Fresh alkalines 60mA
NiMh 30mA

Quoted message said:

Why must it have a boost circuit. 2.4v - 3v is enough for some LEDs.

White leds will operate but only draw 10-15mA.
This particular lamp generates rf. Possibly a switched capacitor because it
is less noisy than a torch that I know uses a coil.

Quoted message said:

Quoted message said:

Actually this brings other thoughts into play: leds are fine for low
power
operation but aren't we getting carried away with ones intended to
illuminate the road?

Quoted message said:

Not really.

Quoted message said:

Quoted message said:

A 2.4W filament lamp costs about £12. Put NiMh batteries in it and it
gives 4 hours operation. A 1W led lamp, costing £26 gives less output
for 8

Quoted message said:

OK. A 1W led (The base unit including lens) costs £12. Some regulation
circuitry can be built for a fiver or less, depending on how efficient
you want it.

But you are talking about homebrew. A bare 5W Luxeon is now $30 retail but
a pair in a lamp end up on the shelves at £270.

Quoted message said:

Quoted message said:

Why not a flourescent lamp? Most such torches only drive their 4W tubes
to about 1.5W; with proper drive and focussing they ought to be pretty
effective potentially.

Quoted message said:

Because it's a royal PITA to focus a flourescent lamp.

Depends what you want. Not a spot lamp for sure.

DavidR nospam_a@t_nospam.com opined the following...

Quoted message said:

White leds will operate but only draw 10-15mA.
This particular lamp generates rf. Possibly a switched capacitor because it
is less noisy than a torch that I know uses a coil.

Not sure what the first argument is about, but the generation of rf
definately implies a switched circuit of some variety.

Quoted message said:

But you are talking about homebrew. A bare 5W Luxeon is now $30 retail but
a pair in a lamp end up on the shelves at £270.

A 3W is marginally better than a 10W halogen (See photos at
www.solidlights.co.uk). A pair of 5Ws would be impressive. The other
thing to consider is that the 1W / 3W are relatively easy to build up,
but the 5W requires some more careful thought about the heatsink in
order to not fry the LED.

Quoted message said:

Depends what you want. Not a spot lamp for sure.

No use for illuminating the road. Might be good for being visible, but
the control circuitry is quite heavy and complex (Requires inverters).
If you're going down that route for visibility, EL strips would make
more sense as these don't take up less space.

Jon

In article said:

A 3W is marginally better than a 10W halogen (See photos at
www.solidlights.co.uk).

It depends. _With fully charged cells_, my "10W" halogen puts out
over 10W, and more light than the 3W SolidLight (equally bright
in the centre, much more light overall). By the time its low battery
warning LED comes on a couple of hours later (from a much heavier
battery pack than the SolidLight), it is only putting out less than
5W and much yellower. In between, at about 8W, its central spot is not
as bright as the SolidLight, but is wider, and the peripheral light
is more.

I could upgrade my light to have a higher voltage battery pack and
a Willie Hunt regulator so it gave a full 10W the whole time for
less than the cost of the SolidLight. The SolidLight would however
have a lighter battery pack and longer runtime.
The SolidLight can also run off a dynamo (or at least SolidLights
that can run off dynamos exist, I only had a battery one to try),
and is definitely better than a 3W Lumotec (assuming the dynamo
SolidLight gives the same light as the battery one).

On 7/12/04 10:22 am, in article [email hidden],

Alan Braggins said:

In article said:

A 3W is marginally better than a 10W halogen (See photos at
www.solidlights.co.uk).

It depends. _With fully charged cells_, my "10W" halogen puts out
over 10W, and more light than the 3W SolidLight (equally bright
in the centre, much more light overall). By the time its low battery
warning LED comes on a couple of hours later (from a much heavier
battery pack than the SolidLight), it is only putting out less than
5W and much yellower. In between, at about 8W, its central spot is not
as bright as the SolidLight, but is wider, and the peripheral light
is more.

Seems like I have a problem with my SLA setup. The battery is stubbornly
refusing to charge. What kind of voltage should I be getting from the
charger (have I accidentally mixed up different PSU?). It is a standard
4.5Ah 6V battery.

Maybe it is time to source a replacement after 6 years of regular use.

...d

David Martin said:

Seems like I have a problem with my SLA setup. The battery is stubbornly
refusing to charge. What kind of voltage should I be getting from the
charger (have I accidentally mixed up different PSU?). It is a standard
4.5Ah 6V battery.

A nominal 6V SLA will be 6.9V at full charge, probably the charger will
show 7.5V open-circuit.

Quoted message said:

Maybe it is time to source a replacement after 6 years of regular use.

Yes, I'd expect so. I have never had any sort of rechargeable last that
long.

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

James Annan said:

David Martin said:

Seems like I have a problem with my SLA setup. The battery is stubbornly
refusing to charge. What kind of voltage should I be getting from the
charger (have I accidentally mixed up different PSU?). It is a standard
4.5Ah 6V battery.

A nominal 6V SLA will be 6.9V at full charge, probably the charger will
show 7.5V open-circuit.

It's the charger. Purely by coincidence I was chatting to one of the
other cyclists in the bike sheds (honest.. we were heading home) and he
mentioned that his Smart charger had just given up as well. So i have
been looking to see what I can fettle.

Quoted message said:

Quoted message said:

Maybe it is time to source a replacement after 6 years of regular use.

Yes, I'd expect so. I have never had any sort of rechargeable last that
long.

The battery has been fine. The charger won't give me more than 5V though
so I presume it is shot. CPC have what looks like a suitable one here
<URL:http://cpc.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=BT02564&N=401>
which shouls hopefully do the trick. Or it is time to invest in a new
battery as well.

...d