Building a standlight lamp

Hi

MSeries said:

I'd like to make use of some cheap 6v lamps I have, with my dynamo. It

[snip]

Cycling Plus did a howto for what you're after several years ago and I had
a go at building it. I can't find the article at the moment (if I
locate it I'll let you know) While it worked it was very effective.

The circuit had some gizmo for switching to my rechargeable bateries when
the dynamo current dropped. The whole unit fitted inside a seven inch
length of two inch plastic pipe.

After several months it started to fail from corrosion. I found it
difficult to seal the unit from condensation effectively. I then abandoned
it for the German manufactured led Standlicht which worked very well and
was much neater.

I've since abandoned dynamos in favour of leds and a twin halogen headlamp
and lead acid rechargable batery pack.
http://www.chainreactioncycles.com/Models.aspx?ModelID=1386

These have served me well for many years now.

bin said:

Hi

MSeries said:

I'd like to make use of some cheap 6v lamps I have, with my dynamo. It

[snip]

Cycling Plus did a howto for what you're after several years ago and I had
a go at building it. I can't find the article at the moment (if I
locate it I'll let you know) While it worked it was very effective.

Quoted message said:

After several months it started to fail from corrosion. I found it
difficult to seal the unit from condensation effectively. I then abandoned
it for the German manufactured led Standlicht which worked very well and
was much neater.

I have B&M lights mit standlicht on my tourer and can't afford to buy
another set. I don't want the hassle of swapping them (as well as the
wheel) should i decide to take the fixed to work one morning. I have a
rear lamp that will work, can get a Basta front for £10 and want the
satisfaciton of building my own system.

If you can find the article I'd be very grateful.

bin said:

Hi

On Fri, 23 Sep 2005 03:11:56 -0700, MSeries wrote:

Quoted message said:

I've since abandoned dynamos in favour of leds and a twin halogen headlamp
and lead acid rechargable batery pack.
http://www.chainreactioncycles.com/Models.aspx?ModelID=1386

Funny. I abandoned a very similar setup from CatEye after 3 years of
use as it vibrated itself into bits for a dynamo. Good though the
rechargable was and I had no complaints about it falling apart after the
miles I had done with it, I would not go back.

The whole thing of "did I remember to turn on the timer last night to
charge the battery" was just to stressful. I never did forget but I
never stopped worrying about it.

Dynamo is just hop on and ride. It even turns itself on when it is dark.

--chris

MSeries said:

I'd like to make use of some cheap 6v lamps I have, with my dynamo. It
will be possible to build a switch box so that I can manually switch
from dynamo power to battery power when I stop. It would be cooler if
this was done automatically as the voltage dropped, does anyone have a
circuit that I can use to build such a device. I am not knowledgable
eough to design such a circuit but I am skilled enough to follow the
instructions to build such a device. Maybe one of the electronics mags
has published it or maybe someone has put it on the web in the past.

The 0.6V diode drop is going to hurt with any naive design.

http://www.nscl.msu.edu/~daniel/sreg.htm

Might give you some ideas (includes the ability to charge batteries)

Looks like he is using a dpdt relay to avoid the diode drop to the
lights

You might be able to achieve something similar using a spdt reed switch
(does such a thing exist?) with two coils, one high resistance directly
across the dynamo and one low resistance in series with the dynamo and
lights but it's going to take a lot of fiddling to get it just right.

Tim.

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

Looks like he is using a dpdt relay to avoid the diode drop to the
lights

You might be able to achieve something similar using a spdt reed switch
(does such a thing exist?) with two coils, one high resistance directly
across the dynamo and one low resistance in series with the dynamo and
lights but it's going to take a lot of fiddling to get it just right.

(KO) DRR-DTH-445

http://www.surplussales.com/Relays/REReed-1.html

The problem with this project is that after all that work you will have
a single light that ,when it goes wrong, will leave you entirely in the
dark.If you bought a cheap clip-on led you have a stand light and,
having two units, some confidence that you will never be without light.
TerryJ