Dynamo LEDs

lardyninja said:

I have a new bike with dynamo powered lights. Does anyone know if it's
possible/easy to replace the regular bulbs with LEDs. A standlight
function would also be useful.

Easier to buy new front lamp.
The B&M Lumotec IQ Fly seems to be getting good comments (note its a new
model, don't confuse with models not carrying the IQ label which have half
the light output). Comes in multiple forms; with/without standlight ;
with/without switch (hub dynamo) ; with/without auto-sensor (comes on
automatic in dark). From circa £40.

- Nigel

--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

lardyninja said:

I have a new bike with dynamo powered lights. Does anyone know if it's
possible/easy to replace the regular bulbs with LEDs. A standlight
function would also be useful.

the BoB do a 3 LED rear bulb replacement. No standlight though and I
have no idea how good it is. Try asking them. I have found them
happy to tell you if they don't like a product they are carrying

http://www.sjscycles.co.uk/src/froogle/product-0-Eco-Bulb-Screw-Fit-MES-Red-4357.htm

hth
james

In news:[email hidden],
[email hidden] <[email hidden]> tweaked the Babbage-Engine to tell
us:

Quoted message said:

the BoB do a 3 LED rear bulb replacement. No standlight though and I
have no idea how good it is. Try asking them. I have found them
happy to tell you if they don't like a product they are carrying

http://www.sjscycles.co.uk/src/froogle/product-0-Eco-Bulb-Screw-Fit-MES-Red-4357.htm

Tried these many years ago. The individual LEDs had a disturbing tendency
to stop working. Not impressed.

--
Dave Larrington
<http://www.legslarry.beerdrinkers.co.uk>
Wood is an excellent material for making trees, but is otherwise
not to be trusted.

lardyninja said:

I have a new bike with dynamo powered lights. Does anyone know if it's
possible/easy to replace the regular bulbs with LEDs. A standlight
function would also be useful.

Ta

LN

One related thought, I found that using the dynamo during long
downhill or extended higher-speed treks tended to blow out bulbs much
quicker...inside of the bulb afterward was nickel-colored, pretty
intense burn out of bulb. Wouldn't LEDs be preferable, prevent this?

Quoted message said:

lardyninja said:

I have a new bike with dynamo powered lights. Does anyone know if it's
possible/easy to replace the regular bulbs with LEDs. A standlight
function would also be useful.

yes

Quoted message said:

One related thought, I found that using the dynamo during long
downhill or extended higher-speed treks tended to blow out bulbs much
quicker...inside of the bulb afterward was nickel-colored, pretty
intense burn out of bulb. Wouldn't LEDs be preferable, prevent this?

you probably have a headlight without zehner diode/voltage limiter, and
a dynamo assuming you do. If you run without a rearlight you need a 3w
bulb, not the standard 2.4w
--
/Marten

info(apestaartje)m-gineering(punt)nl

"[email hidden]" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

lardyninja said:

I have a new bike with dynamo powered lights. Does anyone know if
it's possible/easy to replace the regular bulbs with LEDs. A
standlight function would also be useful.

the BoB do a 3 LED rear bulb replacement. No standlight though and I
have no idea how good it is. Try asking them. I have found them
happy to tell you if they don't like a product they are carrying

http://www.sjscycles.co.uk/src/froogle/product-0-Eco-Bulb-Screw-Fit-

MES

Quoted message said:

-Red-4357.htm

Unlike Dave (whole post Xnews won't let me reply to) I've had one of
these in the rear mudguard light for several years and it's never missed
a beat - excellent value, and now I've got a link to a supplier, I'll be
getting another for one of the other bikes!
This 'bulb' is pretty feeble compared to 21st century LED rear lights
but it's certainly good enough for most situations, but I very rarely
have only one rear light anyway.

[email hidden] said the following on 08/11/2007 18:14:

Quoted message said:

One related thought, I found that using the dynamo during long
downhill or extended higher-speed treks tended to blow out bulbs much
quicker...inside of the bulb afterward was nickel-colored, pretty
intense burn out of bulb. Wouldn't LEDs be preferable, prevent this?

Slow down :-) Seriously, if you're running bulbs you should have a
voltage limiter somewhere in the circuit.

--
Paul Boyd
http://www.paul-boyd.co.uk/

Paul Boyd usenet.is.worse@plusnet said:

[email hidden] said the following on 08/11/2007 18:14:

Quoted message said:

One related thought, I found that using the dynamo during long
downhill or extended higher-speed treks tended to blow out bulbs much
quicker...inside of the bulb afterward was nickel-colored, pretty
intense burn out of bulb. Wouldn't LEDs be preferable, prevent this?

Slow down :-) Seriously, if you're running bulbs you should have a
voltage limiter somewhere in the circuit.

Even with a voltage limiter and a rear light I was blowing the 2W4
bulbs on the Brompton. Since I've changed to 3W I've not had any
problems.

The problem with any simple voltage limiter (I'm using 2 back to back
zeners) is that the waveform becomes a square wave. If you clamp the
peak voltage at 6V then you'll not get 6V rms at slower speeds. If you
clamp the peak voltage at around 9V you'll potentially get 9V rms at
high speed.

I think I'm using two 8v1 zeners - which have at least prevented me
from destroying any more rear lights when the front bulb goes and I
don't notice immediately.

Tim.

Quoted message said:

One related thought, I found that using the dynamo during long
downhill or extended higher-speed treks tended to blow out bulbs much
quicker...inside of the bulb afterward was nickel-colored, pretty
intense burn out of bulb. Wouldn't LEDs be preferable, prevent this?

An LED will help not because it's an LED, but when using an LED power
illuminator, you'll also use an LED power supply to make the right
voltage and limit current. Generally, these are small switch mode power
supplies and will regulate the supply to the LED such that so long as
the input voltage (and current capability) is within the supply's
specified input range, it will always output whatever it is the LED
requires. The input range is generally pretty large - some LED driver
chips will accept input voltages up to 30 volts (and have an efficiency
of 95%)

--
From the sunny Isle of Man.
Yes, the Reply-To email address is valid.