Had a thought last night and wanted to get some input from you guys.
Take a USB rechagable rest flasher afix the charging cord,maybe silicone for a seal, and run the wire up to a Dynamo setup with USB charging capabilities? Maybe 2 rear flasher?

That's only going to work if you have a dynamo that delivers a regulated 5V DC. The USB rechargeable tail lights have a 3.7V lithium polymer battery inside and the electronics to allow it to recharge with 5V DC. When you plug it into a USB charging unit it gets the right voltage for the electronics inside the flasher to recharge the battery. Instead you could wire up a 3.7V Li-ion battery like the 18650 batteries in parallel with the battery inside the flasher. That would give you a much longer run time than the internal battery. I was going to do that with an inexpensive 100 lumen COB taillight but wasn't able to open the light without damaging the case. When the internal battery begins to die, I will sacrifice the light and see if I can use an external 18650 battery. Even the cheap taillights warn you to not go over 5V DC on the charging circuit.

There are lots of discussions about charging from a dynamo hub. It can be done but not cheaply, and it's worthwhile only if you are going to put a lot of miles on between power outlets, such as on a multi-day tour where you are camping. Little external batteries are cheap, and you can carry more than one.

The dynamo produces A/C rather than DC, and the voltage fluctuates widely. You need circuitry to compensate for that. Not only that, it doesn't produce much power, either.

There is a gadget called a usb-werk that converts your dyno hub output to USB power.

And Sine Wave Cycles makes a couple of equivalent gadgets.

Wow, that's an expensive solution compared to buying more than one of the new COB USB rechargeable tail lights. Didn't find any listings for the USB-Werk on Amazon but a couple of overseas sellers show up on eBay with the cheapest being $135 with shipping Busch + Müller USB-Werk für Nabendynamo | eBay

I recently bought four USB rechargeable COB lights - 100 lumens, 500 mAh internal battery and made by the company that makes some lights for Blitzu. Cost was $16 for all four. It's easy to carry a spare if you are worried about exceeding the run time of the light.

Tesla Vs Edison


Hub alternator out put is AC .. USB is DC
your scheme dream skipped the rectifier and voltage regulator you need in between ..

that the sinewave and others similar pieces provide. as No glider suggests..

https://www.sinewavecycles.com/colle...ave-revolution
probably want a handlebar bag* or something.. for the $120 one since its a simple boxy shape rather than the
wire thru the steerer tube , and between the fingers of the star fangked nut their pricier model requires.

* Ortlieb has electrical contacts that let the connection be opened and closed by removing the bar bag
with all your electronic distractions and tools in it.. and putting it back on..
the B&M things are kind of blocky too so into the bag they would go..





.....

Or compared with just carrying more batteries. It's a fair point—with the proliferation of USB-chargeable gadgets and big battery packs with USB interfaces, it's harder to make a case for dyno hubs. But some people may prefer to charge while they ride because they'll be in very remote areas, or it just appeals to them philosophically. I can't argue with that

Yesterday, I rode for 6-1/2 hours with my phone mounted to my handlebars, using two GPS apps. I told my phone to leave the screen on forever. I plugged the phone into a small external battery which I had strapped to the bottom of my top tube, right behind the head tube. The phone's charge stayed at 100% the whole time, and the battery was run down halfway. The battery cost about $20 and weighs about three ounces.

I love my dynamo hub for running lights but not for charging. It's not practical for me. If I rode long bike tours without being near an outlet at night, I would consider a charging system that runs off the dynamo. But if I had that, I couldn't run the lights in the day. I could use it for lights or charging but not both, which is another thing to consider if you are thinking of getting a dynamo-powered charging system.

I charge my garmin constantly so I can use it for brevets. It works. I use a b&m headlight with a usb port. Ymmv. I have a dynamo taillight, a usb chargeable one, and one powered by a button cell lithium battery.

https://buy.ternbicycles.com/products/reecharge-dynamo-kit-with-micro-usb-cable

Dynamo tail lights are cheaper and more reliable than trying to re-charge a USB battery light.

If you work sitting in front of a computer, (from where you post , here), then you have a USB charging plug.

I Too like the 'get on and the lights work'. hub dynamo wired light set up, too..

I keep hoping someone will make a dyno taillight that flashes. Actually, I would like two lights in one, one steady on, and one that varies like a radbot, but never turns all the way off. I have thought about making one, seems like a lot of work. I usually just have two lights, one steady dyno and a battery powered flasher.

[MENTION=136384]unterhausen[/MENTION], I feel the same way, and my solution is the same as yours.

I love your signature, and now that I did well on a few long rides this year, I’m thinking of randonneuring next season.

Ooh very interesting. I hope someone tries and reviews it soon.

I have had one for a number of years (previous version). It is certainly simple and works. It is not currently hooked on my commute bike.

For a real review, one of the electronical types would need to step in with USB testers, data loggers, maybe even an oscilloscope to see whats really coming out of this thing.

If somebody has that equipment and background and wants to test it, I will send it to them.

[MENTION=98328]zebede[/MENTION], when your speed goes down to some slow speed or you stop, does it stop putting out power? Some devices shut off when they stop receiving power. If this charger doesn't have a cache battery, it would be a problem for some people, but I suppose you could get around it by having the charger's output go into a battery and then powering (or charging) the appliance with the battery rather than this charger.

I was inspired by this article and his use of solar charging on bicycle tours.
He addresses several of your concerns, including the use of battery packs (which is what the Biologic unit also does) to avoid the on off cycles when speed drops/dynamo out put drops below threshold.

Solar battery charging for long tours, by Wayne Estes

https://play.google.com/store/apps/d...solarscreenoff

For direct charging of android devices, the linked App keeps the screen off during stopping and starting charging in order to save battery. Specifically written for the intermittent charging issue that a solar cell OR dynamo hub out put causes. I ran this app a couple of years ago when I tried on the Biologic unit on my commuter. I have not had it on a tour or otherwise since.

Here is a DIY Dynamo to USB project:

https://www.arenddeboer.com/diy-hub-dynamo-usb-charger

https://www.cyclingabout.com/best-dy...g-bikepacking/

B&M E-Werk/USB-Werk and Pufferakku allows to convert the voltage from the dynamo to 5V USB.
bumm.de/en/products/stromversorgung.html

With the new Orfos Pro light you would be able to run them directly from USB power.
orfos.us
orfos.bike

I got B&M wired dynamo tail lights, But Being German they comply with the law at home, so dont flash.*

I think until you get a company in Asia to make what you want, the 2 light thing is what you do,

Battery tail lights with red LED dont draw much current, & even less in flash mode..

so until your big crowd funded contract manufacturing dream grows fruit.. whats wrong with 2 lights?





I have a vistalight (2 AA)dangling from my Carradice bag loop, * for the blinky.






....

Two lights is good even if you have a dyno (steady) light because sometimes the connector works loose. The second blinking light keeps you lit when that happens.


And of course a third blinkie keeps you lit when the batteries on light #2 are flat. And ...

Another way to deal with occasional failures is to determine the root causes and make things more reliable, where possible. My dynamo powered headlight has proven to be reliable enough for me that I don't need a backup. I need to improve the connection to my tail light, however.

I'm thinking of carrying a small light for things such as roadside repairs, as a dynamo headlight isn't useful for those.

It is best to send the power from a dynamo hub to a battery back-up that can be used to recharge anything that uses USB. When I am riding and my power pack is full I start rotating electric devices like lights, GPS, phone, MP3 player, electric toothbrush, cameras and on and on. I have 3 different rechargeable LED/reflective lights on my bike and trailer but wouldn't want them hardwired.