Author Topic: Tesco torches on a DynoHub  (Read 9026 times)

Tesco torches on a DynoHub
« on: December 11, 2008, 11:36:39 pm »
Last year I found that Tescos had 3W luxeon torches on offer and suggested on various fora that they could be used as bike lights (yes, sorry, it was me that started the whole Tesco LED torch/bike light craze   ::-) ) I even used my posts to make a webpage showing how I converted one to a super-dooper, mini dymano light.

The light had worked brilliantly for about a year running on a hub dymano on my fixie. Some of you may have seen it on the 'Dun Run'


... This year Tescos torches have had the 'more lumens per watt' 3W Cree LED in their torches. When they dropped the price from £10 to £8 I decided to buy a couple to try a more simple conversion that people who don't have a lathe can do.

I've just posted the new webpage showing how to do it.   :D

I've had them on the bike for the last couple of days, and as yet I'm a bit dissappointed.  :-\
There is more drag from the DymoHub - I didn't notice the drag with the single Luxeon (Infact I did the last time trial of the season with the dymohub light on and posted a quicker time than I did earlier in the season on the TT bike   :P )

Also there is not an impessively greater luminance. I suppose I might notice it more when I'm not riding under a full moon however.   :demon:

There is no complicated 'lectonics - just a bridge rectifier to use more of the AC current through the DC LED.

The lights flash as you start moving, and flicker as you build up speed until they appear constant. The new Crees seem to go through the flickering stage earlier then the Luxeon, appearing constant above about 5mph. I love the flickering though - it really looks different and grabs drivers attention.
If it ain't broke, fix it 'til it is...

Adam

  • It'll soon be summer
    • Charity ride Durness to Dover 18-25th June 2011
Re: Tesco torches on a DynoHub
« Reply #1 on: December 12, 2008, 08:57:19 pm »
Top tip - for £12, there's the slightly larger Tesco torch which has a wider diameter lens.  This gives a much better spread of light compared with the smaller torch.
“Life is like riding a bicycle. To keep your balance you must keep moving.” -Albert Einstein

clarion

  • Tyke
Re: Tesco torches on a DynoHub
« Reply #2 on: December 12, 2008, 08:59:35 pm »
Cool conversion.  Shame you're disappointed after that much effort.
Getting there...

chris

  • (aka chris)
Re: Tesco torches on a DynoHub
« Reply #3 on: December 12, 2008, 09:00:02 pm »
Top tip - for £12, there's the slightly larger Tesco torch which has a wider diameter lens.  This gives a much better spread of light compared with the smaller torch.

Good point, but the battery housing is much larger and unless there is an easy way to reduce the length of them it would make a very bulky light.

Adam

  • It'll soon be summer
    • Charity ride Durness to Dover 18-25th June 2011
Re: Tesco torches on a DynoHub
« Reply #4 on: December 12, 2008, 09:03:20 pm »
Top tip - for £12, there's the slightly larger Tesco torch which has a wider diameter lens.  This gives a much better spread of light compared with the smaller torch.

Good point, but the battery housing is much larger and unless there is an easy way to reduce the length of them it would make a very bulky light.

That's the £18 jobbie which runs on the D cells.  The £12 version still takes 2 x AA's. *

Mind you, in my bodge version, I saw off the barrel anyway.


* Edit - sorry, I should have put that one takes C size batteries.
“Life is like riding a bicycle. To keep your balance you must keep moving.” -Albert Einstein

chris

  • (aka chris)
Re: Tesco torches on a DynoHub
« Reply #5 on: December 12, 2008, 09:44:58 pm »
Top tip - for £12, there's the slightly larger Tesco torch which has a wider diameter lens.  This gives a much better spread of light compared with the smaller torch.

Good point, but the battery housing is much larger and unless there is an easy way to reduce the length of them it would make a very bulky light.

That's the £18 jobbie which runs on the D cells.  The £12 version still takes 2 x AA's.

Mind you, in my bodge version, I saw off the barrel anyway.

I'm confused now. Our Tesco store only has two models, one with AA cells for £8 (I think), the other with D cells for £12 (I think). We have two of the AA version and run them from Energiser Lithiums. Toothgrider recokns they are good for about 6 hours continuous use.

Adam

  • It'll soon be summer
    • Charity ride Durness to Dover 18-25th June 2011
Re: Tesco torches on a DynoHub
« Reply #6 on: December 12, 2008, 10:04:13 pm »
Tesco's must have variable pricing!

The smallest torch is the one Wobbly has, and it's also covered here

It could be with all these pre-Christmas sales and Woollies closing down, that they've brought the prices down, but when I was in there a week ago, it was still £10 & £12 for the tiny and small 3W AA ones * & £18 for the big 4W D cell behemoth.


* Edit - Sorry, I've since realised that it's only the tiny one which takes AA batteries, the next one up takes the C size batteries.
“Life is like riding a bicycle. To keep your balance you must keep moving.” -Albert Einstein

Re: Tesco torches on a DynoHub
« Reply #7 on: December 12, 2008, 11:14:44 pm »
it's also covered here

The one I mentioned in that thread as being available free (well, a £ or two for postage), still is. Available.

zzpza

Re: Tesco torches on a DynoHub
« Reply #8 on: December 14, 2008, 01:16:03 am »
good find! i think i'm going to fight off the great unwashed tomorrow at the local tesco and see if they have any left... :D

Re: Tesco torches on a DynoHub
« Reply #9 on: February 07, 2009, 09:46:16 am »
Just picked up 2 of the AA torches from my local tesco.  They're now £7.83 each (bless Gordon Brown and his VAT cut), and I've just burnt out my retinas testing one out.

Re: Tesco torches on a DynoHub
« Reply #10 on: February 07, 2009, 04:35:50 pm »
Just had a look at your website for wiring these up to a dynamo.
Does the polarity of the dynamo matter?
Another thing which may be worth considering is to solder a short wire, long enough to reach the other end of the barrel so you can connect the wires after you've screwed the switch on, from each switch and put an insulated connection at the other end of the wire. Then instead of soldering the wire from the dynamo to the switch, just connect it to the connector of a switch. Because you have done this to both switches, you now have a backup switch. It's almost always the switch that will let you down on a lighting system, especially if you do a lot of wet riding. Remove the spare switch and plug the end of the light unit to prevent water getting into your light. Now you can store your spare in a dry saddlebag instead of exposing it to the elements.

I like the bracket too. I can do something like that which can be used for either drop bars or my tri bars. I'll be trying this soon, once I've built my dynohubs into some wheels.

Re: Tesco torches on a DynoHub
« Reply #11 on: February 07, 2009, 08:09:40 pm »
Just had a look at your website for wiring these up to a dynamo.
Does the polarity of the dynamo matter?


You need to insulate the lights from the bike if your dynamo uses the bike as an earth - the plastic on my bracket does this. The dynamo produces ac current.

In my experience, connectors are the most likely cause of contact problems, thus my preference for soldered joints.

BTW, the lights were £7.83 when I bought them - the price on the shelf was still £8 then.

If it ain't broke, fix it 'til it is...

Re: Tesco torches on a DynoHub
« Reply #12 on: February 08, 2009, 07:14:15 pm »
Just had a look at your website for wiring these up to a dynamo.
Does the polarity of the dynamo matter?


You need to insulate the lights from the bike if your dynamo uses the bike as an earth - the plastic on my bracket does this. The dynamo produces ac current.

In my experience, connectors are the most likely cause of contact problems, thus my preference for soldered joints.

BTW, the lights were £7.83 when I bought them - the price on the shelf was still £8 then.



I'll be using my Schmidt. I've never had a problem with the crimp connections, which are also used for connecting the wires to a Schmidt hub dynamo.

Re: Tesco torches on a DynoHub
« Reply #13 on: February 14, 2009, 07:27:11 pm »
Schmidts are insulated from the fork - Shimano DH's aren't.
Never tell me the odds.

Adam

  • It'll soon be summer
    • Charity ride Durness to Dover 18-25th June 2011
Re: Tesco torches on a DynoHub
« Reply #14 on: February 14, 2009, 07:38:53 pm »
Good reason for having a carbon fork then.  :P
“Life is like riding a bicycle. To keep your balance you must keep moving.” -Albert Einstein

Re: Tesco torches on a DynoHub
« Reply #15 on: March 13, 2009, 11:21:11 am »
If anyone needs a twin mount for these tourches. (Wooden former that sits the torches just above a 1" handlebar mount, torches cable tied to the wood bit) bottom of the former is a bit of alumnium. Wood sprayed black.

Give me a nudge.

fruitcake

  • some kind of fruitcake
    • Bailey
Re: Tesco torches on a DynoHub
« Reply #16 on: March 14, 2009, 12:32:43 pm »
Hi Peter,
What payment would you require for a torch holder posted to UK?

Re: Tesco torches on a DynoHub
« Reply #17 on: March 15, 2009, 10:55:29 pm »
What payment would you require for a torch holder posted to UK?

Errrm not too sure how much it would cost much to post, chuck me a PM with your address in.

fruitcake

  • some kind of fruitcake
    • Bailey
Re: Tesco torches on a DynoHub
« Reply #18 on: March 22, 2009, 11:36:42 am »
Received with thanks peterc.

Re: Tesco torches on a DynoHub
« Reply #19 on: May 08, 2009, 10:56:20 pm »
wobbly, you are good with a lathe & mechanics.

4 years ago I started experimenting with 3W luxeons, I have built 2 sets of 6 watt lights (2x3W)

You really need a switching regulator to get power match  from the hub to the LED's I'm quite happy for you to use my designs but you need to be very good at electronic construction.

My design compares well with SOlidlights, 1, Brighter at slow speed, 2 waterproof, 4, no drag when off.




Re: Tesco torches on a DynoHub
« Reply #20 on: November 04, 2009, 03:09:52 pm »
I notice the reflector/lens/optic thing is seperate to the LED, are these a standard size that can be changed? If so has anyone tried a wider throw?

Now it's got proper dark in the evenings I'm reasonably impressed by these, and tend to only use one of my two mounted torches at a time.

Re: Tesco torches on a DynoHub
« Reply #21 on: December 30, 2010, 08:53:47 pm »
Well, just goes to show you should read before fettling...

Having just finished a dyno hub wheel build (thanks Santa) I tried to wire two of these together to test the wheel, looks like after much failing I seem to have made a small amount of smoke and killed one of my torches, ho hum.

On the basis it was broken I took it apart to see how it worked, now with batteries its very dim, only just on, so took the lower PCB off and just wired in the emitter in, in for a penny.

Seems that this works okay is just bodged into the hub, very draggy but plenty light comes out the front, may work at a back up/get you home for the Cyo when it arrives.

Rather than use the barrel, I've gone for half an wine cork, with the wire pushed down the middle, should make is all waterproof.

Re: Tesco torches on a DynoHub
« Reply #22 on: January 02, 2011, 06:36:24 pm »
Added a bridge rectifier, which since I worked out what they do, makes much sense.

So the message is, if you fry the PCB below the LED itself, it seems you can run them of a dynamo singly rather than in a series pair.