Dynamo LED lights interfering with Garmins?

[bikey-mikey]

I was researching dynamo LED lights and came across this website

http://www.peterwhitecycles.com/schmidt-headlights.asp

The specific bit that worried me was

LED Headlights and Wireless Computers

Some wireless computers don't work with some dynamo powered LED headlights, and even with some battery powered LED headlights. For example, the DLumotec series lights from Busch & Müller seem to cause some wireless computers to stop working.

Do they mean Garmins, or have I got the wrong end of the stick?

Anyone had the problem, or anyone using a Garmin and high powered dynamo LED light successfully?

[Adam]

No, they mean some LED lights interfere with the operation of some types of wireless cycle computers, not GPS units.

Although having said that, the SatMap Active 10 GPS does also affect my wireless computer, if the screen brightness is turned up high.

[Greenbank]

And I've had no problems with a dynamo LED light (Solidlights XB2 and B&M IQ Fly) and the GSC-10 speed/cadence sensor that communicates wirelessly (via ANT+) to my Edge 705 GPS.

At least the GSC-10 sensor is nowhere near the front wheel and therefore nowhere near the light, dynamo or cabling (since it sits just behind the bottom bracket) and doesn't have the light in the path between sensor and GPS.

[Kim]

There's a repeatable measurable drop in GPS signal strength on my old, non-H eTrex Legend when mounted immediately next to my Ixon IQ (battery version of the IQ Fly).  Not normally enough to cause it to lose a fix, unless it's already marginal due to trees.  The more sensitive receiver in the Vista HCx, on the other hand, doesn't bat an eyelid.

I've never noticed a problem with my dynamo-powered IQ Cyos, but they (and associated wiring) are mounted further away from the GPS brackets.

But in reference to the OP - it's referring to computers with a low-power radio link between a wheel/cadence/heartrate sensor and the computer itself, rather than GPS receivers.  These are notoriously sensitive to interference, to the point that I consider them to be a work of Stan anyway.  I also work on the principle that if you're happy to run wiring for dynamo lighting, then why not run wiring for the computer sensor(s), too (indeed, you can do quite a neat job if you run them together)?

AIUI it's not the power source that's the issue - even the rather trippy waveform of a dynamo powering a non-linear load isn't that noisy at RF - it's the switching regulators inside newer LED lights (I expect electronically simple ones like Solidlights are okay) that tend to make noise.

[clarion]

You've answered my next question, which was 'Is there any adverse effect from running the cables together?'

[Kim]

You've answered my next question, which was 'Is there any adverse effect from running the cables together?'

Not on a purely wired computer.  I can't vouch for one with (say) a wired cadence sensor and a wireless wheel sensor (why do they do this - there can't be that many suspension fork users who care about cadence?), where I can imagine it might well make things worse.

[bikey-mikey]

Sounds good, thanks.

Having dynamo wheel built, to match present wheels - just a tad heavier.  For a 600 km audax, could use as front wheel, and have great lighting, but also have option to use in my Extrawheel trailer, and keep bike lighter for daylight rides, esp. Grimpeur specials like Tregaron Dragon.  Wiring might be an arse, but not insurmountable.

Will ensure that Supernova E3 is mounted as far away from the Garmin as possible....

Cadence: Will be going Vector (pedal based power meter / cadence due out March). Hope pedal transmitters will avoid interference - you can't wire them.  I use high cadence on longer rides to keep legs fresh, but tend to drop to 60 rpm if not concentrating, hence pushing higher gears.  This probably helps build power, but tires me more quickly.  Hence need for reminder what my cadence is..

Heartrate monitor: no wired version so pot luck on that.  I need the data - keeps me from overdoing it, otherwise

LEjogLE: For my NOT quite planned and NOT quite date fixed camping extraganza, the plan is to use the dynamo in the day to recharge my Tecknet 5000mAmp battery, so that at night in the tent I can top up my phone, iPod, Garmin, etc

My research suggests that I would need to use an ewerk http://www.peterwhitecycles.com/ewerk.asp to get the maximum flexibility.  Yes??

[Kim]

Having dynamo wheel built, to match present wheels - just a tad heavier.  For a 600 km audax, could use as front wheel, and have great lighting, but also have option to use in my Extrawheel trailer

That there is a bloody genius idea, and one that could be dead handy to tourists of the wanting to charge lots of stuff persuasion.

My research suggests that I would need to use an ewerk http://www.peterwhitecycles.com/ewerk.asp to get the maximum flexibility.  Yes??

I've yet to hear a bad thing about the e-werk, other than cost.

[marcusjb]

Going slightly OT - but the E-werk does do what it says on the tin for sure.

I put off buying one for ages because of the costs - but pleased I did.  I used it on PBP to charge a Portapow battery pack to try and keep my iphone and GPS alive.

I learnt a lot about managing the battery life of things - and, in the end, finished PBP without the GPS and enough phone charge to send about 3 texts and 1 tweet!

The big problem with the setup is the amount of time it actually takes to charge the battery pack - Portapow say on the website 6-8 hours - but that's plugging it into a solid USB connection.  Even with cycling as much as you are on PBP, I struggled to keep the Portapow going and charging up enough to keep the devices going.  Partly this was because I started on a slightly flattenned portapow - I'd ridden down with it fully charged, but then used it to charge my phone in my hotel (I wasn't carrying any chargers or such) - so that used a good chunk of the batteries - I then didn't ride my bike much for the 2 days leading up to the event.  The first day, I didn't get charging the battery until lunchtime when I remembered about it - so from then on, I was fighting a slightly losing battle.

Obviously PBP is a different game to touring - so the problems of trying to keep everything running 24/7 disappears.  In this case, a good day of touring should charge up the pack which could then keep you going for a couple of days charging GPS and phone (assuming you turn GPS off at night etc. unlike PBP)

So yes - E-Werk does work brilliantly - it's expensive, but works well as long as you manage the charging of battery packs well.

[border-rider]

AIUI it's not the power source that's the issue - even the rather trippy waveform of a dynamo powering a non-linear load isn't that noisy at RF - it's the switching regulators inside newer LED lights (I expect electronically simple ones like Solidlights are okay) that tend to make noise.

well, except that the link that wireless computers use isn't strictly RF; it's audiofrequency near-field inductive coupling.  They use RF chokes as the sending/receiving coils, but that's just poor design and space constraints

This is why wireless computers (and HRMs) are notoriously prone to glitches and interference from almost anything - it's such a weak coupling with such tiny coils that the signals concerned are tiddly and the input amp on the receiver is wound right up.

GPS should be listening at much higher frequencies and should be a properly-designed receiving system.  That's not to say that other bits of the GPS unit won't be interfered with, though...

[alexb]

My dynamo + Solidlights work fine with my wireless (Cateye) computer.
However, if I switch on the GPS, then the screen on the Cateye just goes blank on me. If I switch modes on the GPS I get the signal back.

[Kim]

well, except that the link that wireless computers use isn't strictly RF; it's audiofrequency near-field inductive coupling.

Really?  No wonder it doesn't work!   

[border-rider]

It's amazing it ever works at all.

[bikey-mikey]

    anyway I have now had the new dynamo wheel built, and it is way lighter than the 2 kg wheel supplied by Extrawheel, which even at that weight still has no dynamo. 

For a front light I'm going with a Supernova E3 Triple - 690 lumens - which as far as I can see (good pun, eh?) is THE light for those all night, winter darkness, back lane, potholey, gravelly, brambles in your face, no moon whatsoever, signposts hidden somewhere at shoulder level, rides that we all love. Oh yes, in the rain, of course...

I have decided to try to do without the ewerk, which is saving me loads of dosh, and instead, on good advice from yacf, I have bought a further two Tecknet 5000mAmp batteries for about 44 squids.  I'll run the dynamo wheel on the front of the bike and my really light front wheel in the trailer.  That way the cable runs are easy, and I am set up for night events.  In day time, touring, I can charge one or more of the tecknets, keeping them in my tri bag, and use the third to keep the garmin running forever.  Three Tecknets will keep the Garmin going for about 100 hours anyway, sans any charging. (Plus another 12 hours on the Garmin's own batteries) - enough for Lejog anyway...

If I am doing a one day or less daytime event, I'll simply swap the extra light wheel onto the bike...

Oh, and I'll make sure the Supernova is on the opposite side of the handlebars far away from the Garmin, just in case

[Manotea]

Answering the OP, my SON/Solidlights rig knocked out my Polar HRM/Computer (old tech now but 200squid at the time) which was part of the justification for getting a Garmin Vista which has given trouble free  night time riding.