Dynamo lights

"John Hearns" <[email hidden]> wrote in message
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Quoted message said:

I was buying a 2-second tent as a present in Decathlon today,
and of course went to look at the cycling goodies.
They have a dynamo lighting set for 12 quid, made by I think
Jos in the Netherlands. Front and rear lights, brackets and
what must be a cheapie dynamo. I thought of it for my Halfords
hub gear bike. The front light has billed as a halogen. The rear
has a BS stamped reflector and a BS stamped light. What put me off
was that the light had a bulb, just like the Ever Readys of old.
I don't really trust filament bulbs - give me a decent LED any day,
which is of course legal now.
Anyway - opinions please. Would it be feasible to replace the filament
bulb with one of these LED bulbs, and where would I find one?

Take a bit of veroboard cut to fit the rear lamp where the reflector is.
Solder in 24 or 25 ultra-bright red leds in parallel, 12 pointing
(electrically) one way, 12 the other. Put the entire thing in series with
the front lamp and dynamo. Then you'll have a rather good rear lamp.

(I think it will be rather a lot better than the led bulb-replacements)

Quoted message said:

I also have a decent set of Cateye headlamps languishing in a cupboard,
as I can't be bothered pratically disassembling a bike every time I want
to lock it up. The idea here is to have a cheap setup permanently on the
bike.

I went for a slightly different variation, which is an expensive-ish setup
permanently on the bike :-) (SON)

cheers,
clive

John Hearns said:

I was buying a 2-second tent as a present in Decathlon today,
and of course went to look at the cycling goodies.
They have a dynamo lighting set for 12 quid, made by I think
Jos in the Netherlands. Front and rear lights, brackets and
what must be a cheapie dynamo. I thought of it for my Halfords
hub gear bike. The front light has billed as a halogen. The rear
has a BS stamped reflector and a BS stamped light. What put me off
was that the light had a bulb, just like the Ever Readys of old.
I don't really trust filament bulbs - give me a decent LED any day,
which is of course legal now.
Anyway - opinions please. Would it be feasible to replace the filament
bulb with one of these LED bulbs, and where would I find one?
I don't mind the cheapie dynamo, and I'm not going to run out and
spend hundreds on a German made setup.
I also have a decent set of Cateye headlamps languishing in a cupboard,
as I can't be bothered pratically disassembling a bike every time I want
to lock it up. The idea here is to have a cheap setup permanently on the
bike.

Only flashing LEDs are legal as far as I know. I wouldn't worry about
that technicality though

I find the problem with cheap set ups is that they slip a lot in the
wet and in doing so can wear a trench in the tyre, and the dynamo cap
gets a flat bit and never works properly again.If you can get it set up
very well and attach the adapter to the frame so that it does not move
or bend( a good stiff one that screws to the brake fittings may be
best) you have a good chance of success.I would not bother fiddling
with the bulbs except to put in a zener diode to limit the voltage so
you don't blow the bulb every fast hill.An easier alternative is to put
a 2.4 watt bulb in both front and back .You get less light at normal
speed but the bulbs don't blow.
I have got two in the garage but now I have a hub system again I am
unlikely to bother with them again.
TerryJ

John Hearns said:

What put me off was
that the light had a bulb, just like the Ever Readys of old. I don't
really trust filament bulbs - give me a decent LED any day, which is of
course legal now.
Anyway - opinions please.

Rear LED lights last for ages, so you could power just the front lamp from
the dynamo (actually an AC generator) and use an off-the-shelf LED for the
rear. You'll need to upgrade the front bulb from a 2.4W to 3W.

OR, you could wire a bunch of LEDs in anti-parallel as Clive has already
posted. I can confirm that this results in a very efficient and annoyingly
bright rear light :o)

(I have a Luxeon LED plus a Lumotec 3W front light, and a rear light as
above. All wired in series powered by a SON)

"Nick." <[email hidden]> wrote in message
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Quoted message said:

(I have a Luxeon LED plus a Lumotec 3W front light, and a rear light as
above. All wired in series powered by a SON)

Just bang the luxeon in, no extra circuitry, or is it switched as well?
Possibly just what I'm looking for.

cheers,
clive

Clive George said:

Just bang the luxeon in, no extra circuitry, or is it switched as well?
Possibly just what I'm looking for.

Despite being a diode, the Luxeons are not rated for reverse bias. I'd
protect it with a series diode.

Jon