PdalPowr

Just so I can understand the reason/s behind it.
Take your average one dollar bike light.
You know the kind. A silicone housing that wraps around your handle bars.
Waterproof switch on top and four reasonably bright white L.E.D.s aimed forward.
Not really good for illuminating the road. But great for letting cars know I am there.
Single large watch battery that lasts me a whole Season. And that is without
turning it off when shopping or eating out. It has three functions. Steady light,
fast flash and slow flash. Everything else being equal.
Does it consume less power on slow flash?
As opposed to a steady light.

DrIsotope

Most LEDs in lights are pulsing all the time-- just as a rate too fast for you to see it with the naked eye. But snap a burst of photos of a bike headlight solid on, and it will be on in some, off in others.

Flashing mode just stretches out the time between the pulses, so it will use less energy than a light that is "solid" on. If the pulse timing is say 10ms in solid on, taking that to 500ms (2 pulses per second) could use as much as 50x less energy.

njkayaker

The slow and fast flash (probably) peak at the same output level. Slow (probably) means the light is emitting light for a higher percentage of time (the fast flash is emitting light for a very short period). That is, the slow takes longer to get to the peak and down from it than the fast flash does.

steady > slow > fast.

canklecat

Ditto, the continuous flashing state of LEDs. It shows up in some car headlights on my bike videos. To the eye it appears steady but it's not.

AFAIK, Cygolite is the only manufacturer that provides complete runtime estimates for their Hotshot taillights, which have half a dozen or so modes from steady to flashing. Check out their website to see how much difference flash interval and duration makes.

August West

My Cateye Volt 700 lists the following run times. Flashing greatly extends the time. 50 hours vs. 10 hours for the same light output. I can attest that it seems to run forever since I only run in flashing mode. Never had it go flat on me.

Dynamic mode 700 lumens：2hrs
Normal mode 300 lumens：3.5hrs
All-Night mode 100 lumens：10hrs <-----------
Hyper Constant mode 800/100 lumens：7hrs
Flashing mode 100 lumens：50hrs <------------

tomtomtom123

Activating flashing lights on a bicycle on the road is illegal in some jurisdictions.

Some lights have a 50% lower output setting, which simply strobes slower with longer off time in between. The 100% setting strobes faster. Oh my lights, the 50% setting looks persistent, but if I wave it very fast from side to side then it appears to be flashing at a very high rate.

It's the same method that cheap lcd monitor displays control brightness, by strobing the backlight.

PdalPowr

Thanks.
I was wondering if the circuitry itself necessary for a flashing light consumed power.
Really the question is mostly for fun but I may just disassemble a light enough for me to throw an ammeter on.
Its going to be a long Winter for me. I might as well enjoy the down-time as much as I can.🤗

njkayaker

Sure, the circuitry uses power, but it's (probably) a small percentage of the power to the light.

PdalPowr

That is one question it would have been good to ask in class.
Although the instructors almost always said to find out for yourself.🤗

njkayaker

It’s almost certain that it’s the light consuming almost all of the power.

unterhausen

I had an embedded project that worked fine down to about 5% on time. I was too lazy to go further. The power consumption went way down, even though some of the peripherals were still on. I have thought of using that same processor for a taillight, I would try to go to a lower percentage of time than that. I was sending and receiving over radio, which is a bit more demanding than just monitoring for button presses and changing light modes.

PdalPowr

I am about the only adult in town that bicycles,especially in Winter.
My central location means I can do all my errands and carry about twenty pounds with relative ease. I don't think flashing lights are illegal here. Though I do agree there are limits. I saw a motorcycle with a flashing headlight that seemed so bright you could weld with it. 🤗😣🤗

njkayaker

Flashing lights are illegal in Germany and the police there (being German) are somewhat likely to bother you if you are flashing at night. From experience, it doesn't seem they care about it during the day.

In the US, there doesn't seem to be any jurisdictions where it's illegal. And, I doubt any cop is going to care anyway. I suspect the situation is the same in Canada.

PdalPowr

I agree on the North American attitude.
The cops here are county mounties and way too busy to bother a rider trying to stay safe.
In fact I was going to buy several sets of these lights to give to the Provincial cops to give away.
Its a win/win situation with them coming off as the good guys.
Of course kids won't use them to be safe.
Its just some flashing bike bling to them.😀
Lord I remember when my mom got me a dynamo light set.
I ran it during the day just for fun.😉

PdalPowr

Say what now? 🤗
Gosh that sounds like complex fun.
I guess you have an oscilloscope.(sp)
We didn't get to use them much.
Just an understanding of the basic functions.
I did get an instructor that drew the basics of how an ammeter works.
That drawing isn't exactly stuck in my head but I think I could draw it again given time.
It proved useful to me once as a foreman I liked was hesitant to use his ammeter on his car.
It made me feel good to help the guy who helped me.

Deal4Fuji

NiteRider has run times listed on their packaging. Flash mode looks to save quite a bit of power vs a solid beam. On this example the same full power headlight will run 6 hrs 30 min on flash and 1 hr 30 min on solid

PdalPowr

Cool beans.😀