Aznman

My dynamo headlight was the Planet Bike 1 Watt Version. https://www.amazon.com/Planet-Bike-1-...e+dynamo+light
The reviews were quite consistent, and I was initially happy with the quality of the lights. One day- however- as I was riding at night, my headlight suddenly stopped working. I checked to make sure that the headlight was plugged in correctly ( YES, I converted my headlight to a removable version), but have to ultimately commute back home in the dark.

The next day, I immediately checked my dynamo. The dynamo was working completely fine and was producing the most robust of electricity. I knew then that there was something wrong with my headlight. I began to check out my headlight more carefully. The LED was fine as I checked by connecting it directly to a battery. The capacitors were also fine. This leaves only an extremely tiny compartment that contains the computer chip. I knew then that there must be a short somewhere there.


(an unspecified amount of time past)
After many long hours and days of the most careful considerations, I finally found the courage to explore this extremely tiny compartment containing the bulk of the headlight's electronics. The computer chip was the only accessible part, so I started by removing it first. I did not have any soldering irons, but I was not afraid; basic sense tells me that it is likely that the chip was already broken. And so I moved on courageously, not afraid to be courageous. It broke my heart then to find out that - for an already extremely tiny compartment - there was an initially inaccessible (and hidden) diode. This diode is located between the source of the dynamo and the computer chip. I checked this diode using the multimeter - AND SURE ENOUGH, THE DIODE IS THE ONLY ONE WITH ELECTRICAL CONTINUITY IN BOTH DIRECTIONS. IN OTHER WORDS, THE DIODE WAS WHERE THE SHORT OCCURED, AND I MAY HAVE TRAGICALLY RUINED A PERFECTLY FINE COMPUTER CHIP.

You have disappointed me yet again, Potentially-Callous Dynamo Cyclists. I have so faithfully given the dynamo camp $58 dollars, hoping like any humble person that I will receive quality products. And now, I may be forced to bleed and sacrifice much more with Busch and Muller, well known blood sucking gods of this world . I will continue to support dynamos, but I must issue a warning: do not toy with this faithful person too much; there is a limit to how much a humble and considerate person can handle. Keep in mind that batteries are much cheaper, still far brighter, and are not as pricey to replace if things go wrong.

End of this quasi-comedy/rant.

Mr IGH

I would have called PlanetBike and explained the situation, I'm sure they would have replaced the entire headlamp without any additional expense to you. I do feel your pain (honestly! ).

Perhaps it's a sign that you're due for a new, better headlamp. In for a penny, in for a pound (£), time to lighten your wallet

Drew Eckhardt 

FWIW, next time spending the same money at starbike will get you a much brighter Busch & Müller Cyo Premium T Senso Plus (with daytime running light option) or Cyo Premium Senso Plus.

rumrunn6

seems like a lot of work for just 1 watt of light

unterhausen

I thought about getting one of those for about 15 minutes, mostly because I didn't realize my LBS could order from Peter White. There are definitely better lights available. PB would probably still warranty it. It's often tricky to test diodes unless they are removed from a circuit. There are circuits you can use to test them in combination with a oscilloscope, but I've never bothered.

I would get the cheaper Eyc from my lbs instead of a PB anything

rifraf

My deepest condolences.
By sheer luck my Edelux 1 is still going well after four years.
At this rate I'll never get to sample the exotic MK2 version.
I don't want to even think I may miss out on the MK3........
Life is so unfair sometimes......

fietsbob

It happens... Ist LED headlight was temporary too.

My Brompton-Shimano wheel stopped power output in its 2nd year 1 year past warrantee of course .

The B&M lights were still OK, so I bought the Schmidt XS hub wheel & improved the plug, too.

kickstart

Yeah, using a planet bike headlight for a dyno setup doesn't make much sense when there's far better ones for the same price.

Mr IGH

It is the only dyno headlamp that has a blinkey function, otherwise its 1watt LED is way behind the times. No shaped beam, weak power, what's not to like

steelbikeguy

I'd have to get better descriptions of the parts and probably would need pictures, but my guess is that the shorted diode was a bidirectional zener that is there to protect the light from excess voltage. It's common for them to fail shorted when they have to handle too much power. It's possible that replacing the zener might bring the light back to life.

Can you describe the circuit and your actions in more technically precise terms? I can't tell if you were simplifying the story for the sake of the audience or not.

thanks,
Steve in Peoria

vol

The best thing is that the OP is alive and sound, didn't have an accident that dark night. Could be much worse

I always carry extra lights. Headlights, taillights, side/leg lights. Just in case...

Aznman

Unfortunately, I cannot, for I only have time to buy Busch and Muller now.

rifraf

I take my hat off to you to be able to pull your broken one apart and have a clue at what your looking at.
Miles in front of my knowledge which ends much sooner - at the "thats a circuit board" stage.

Hopefully with your new headlight you'll not have to heat up the soldering iron but can concentrate on pedalling.

Will you be contemplating any upgrades like a charging system for say a phone, gps or headlight torch?

Aznman

Thank you for the well wishes. I do want to create some charging systems (using the dynamo to re-charge the batteries instead of inefficient capacitors) so that my bicycle can be "entirely" indepedent, but I just don't have the knowledge, tools or the time right now.

I keep hearing contradictory information about the safety of re-chargeable Ni-CAD batteries being charged while in use.

no motor?

Redundancy is good when it comes to light.

steelbikeguy

Regarding efficiency, I would say that capacitors are at least as efficient as batteries. There is less power lost when charging capacitors than batteries. If you are actually referring to the ability to store power, then batteries have a higher energy capacity for a given package size.

I've designed my own dynamo headlights with good standlights, using both a AA nicad cell and a 100F super-capacitor to drive the same standlight circuit. The AA nicad will power the standlight for 30 minutes, while the 100F super cap will power it for 10 minutes. Both are more than enough. The 100F super cap is more expensive and bigger than the AA nicad, but the AA nicad is cheaper and heavier.

The only risk of using nicads is that they will vent a small amount of hydrogen if severely overcharged. In general, they are about the safest type of rechargeable battery. It's pretty easy to design a charging circuit that won't overcharge a nicad pack, even while using it.

Steve in Peoria

Aznman

That is good to hear. Yes, I was talking about energy capacity in the comparison. I may try this later, but without the capacitor. People always say that the price of 100 Farads is just not worth it compared to the batteries that you can just buy as replacements.

steelbikeguy

well, I got the 100F cap from a friend for free, so I avoided that particular issue on my latest light.

I've used a single AA nicad on 3 or 4 earlier lights. The only downside is that it will eventually die. I charge the nicads pretty gently, so I've seen one go for about 10 years before it needed to be replaced. The rest haven't failed yet.

My usual charging method is to use voltage regulation and to charge it to about 1.3VDC.

Steve in Peoria

Aznman

Curses

fietsbob

old bottle dynamos were DC , now theyre AC, so for battery charging a bridge rectifier turns the AC to DC

its a common part of power-supplies.

vol

That's why I think it makes more sense to have many inexpensive but good quality lights than having just 1 or 2 expensive lights.

Aznman

Very very true. I am glad that I waited for a certain good Busch and Muller model to decrease in price. Even when combined with my old headlight, the money lost would still not reach the ludicrous level above $120 dollars (minimal price of some single B&M headlights). All I need to do is to hook up my removable LED to the new circuit!

mcahill844

I have a B&M IQ Cyo Premium dyno light and a B&M IXON Premium battery light on my front. I have a B&M Toplight Plus dyno taillight and a Cateye LD1000 battery taillight on the back.

They are all mounted and I run them all at the same time. They give plenty of light. They provide an excellent beam pattern...as one light supplements the other. I don't have to worry about system failures. And I don't have to worry as much about charging batteries as battery failure is not a huge deal.

Both the battery lights run on easily available AA batteries. So if I'm away from a charger for days I can just pick some up at any store.

vol

Do AA flashlights last much less on full charge than 18650 flashlights? Say 4xAA versu 4x18650? my flashlight on 4x18650 could only last about 40 min on high, and maybe just twice on low, so although I hope to get an AA flashlight (more common battery, and less weight), I'm concerned about how long it will last on a full charge.

mcahill844

I get about 4 or 5 hours out of the double AAs in the headlight. My bet is your flash light is putting a lot more power than my battery light alone. That is what is nice about having the dyno light too. I have a Magicshine on my beater bike. My too headlights together light up the road as brightly as the magicshine without the spill.