Hard wired 6V tail light, I want it to flash constantly, how?

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jpacadd   10 mW

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Hard wired 6V tail light, I want it to flash constantly, how?

Post by jpacadd » Jan 05 2020 7:44pm

I see these GS-100 inline module tail light flashers for sale, but those only cause 4 flashes then continuous, according to the descriptions.

I want my tail light to flash constantly.

I had a couple of independent led tail lights with their own batteries, which flashed as I like, but I lost both of them so I'm done with a separate light, so I want it mounted permanently and to run off the 6V light lead on my BBSHD.

I bought the 6V Bafang tail light, which works fine, but I like my bike to look like a bicycle, not a motorcycle, and all of the bicycle taillights that I have seen flash, and so I want mine to flash.

It can't be too difficult, there must be an inline module that I can add to my taillight circuit (similar to the GS-100), but I'm not finding one yet. I figure I could do it with a directional flasher, but those are so bulky, would be unsightly wired inline between my motor and taillight.

Anybody know how to achieve what I want without an automotive style flasher relay cube?
July 2019 first build: 2009 Giant Trance X3 with stock BBSHD 52V
Next build: Just bought used 2009 Giant Trance X4, likely BBSHD also, maybe hotter controller/battery, undecided
Lots of other fun toys: Wildcat X, Xtrainer, 1978 KE100, Hypermotard 1100

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amberwolf   100 GW

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Re: Hard wired 6V tail light, I want it to flash constantly, how?

Post by amberwolf » Jan 05 2020 8:18pm

you can look up 555 timer, astable multivibrator (oscillator, flasher, blinker) mode, and design and build a circuit that does what you're after. depending on the current hte light needs you may need a transistor power output stage.

or there are individual-transistor-based circuts that will do it, but they're probably going to need more figuring out on your own than the 555 stuff, which is all over the web with existing circuits.

or you can take apart a removable 6v taillight and wire up it's flasher electronics to your light, once you figure out how it works.

but it's much simpler to use 12v instead of 6v lights, and then use automotive flasher units meant for leds. the flasher unit isn't very big, maybe an inch on a side or so, and will not be much, if any, bigger than the circuits you can build yourself (including weatherproofing), because it uses surfacemount parts. if you have a weatherproof place to put it, you can take the small board out of the flasher case and it's much smaller. just remember to seal the casing if you keep it in the original, as they're not usually glued shut so water can get in there.

there may be other flasher boards out there that run on 6v instead, but haven't seen them myself.


alternately you could simply permanently mount the removable lights, with whatever hardware you need to do that with. lots of stuff at various hardware stores that could be adapted to the purpose.

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jpacadd   10 mW

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Re: Hard wired 6V tail light, I want it to flash constantly, how?

Post by jpacadd » Jan 05 2020 8:47pm

amberwolf wrote:
Jan 05 2020 8:18pm
you can look up 555 timer
...
alternately you could simply permanently mount the removable lights, with whatever hardware you need to do that with. lots of stuff at various hardware stores that could be adapted to the purpose.
Thanks for the input. After further thought, directional flasher is too slow anyway, though they get faster if a bulb is out, hmmmm...

Not a big fan of the 555 timing options either, sounds slow and lazy for my purposes. Maybe you're right and my best bet will be to buy yet another standalone rechargable bike tail light and try to adapt the PCB inline permanently. I don't want to permanently mount that because it requires independent charging, and I'm looking for simple.

Thinking maybe I can adapt some wigwag module, but the power seems much higher and 12V. What happens if I try to run a 12V module at 6V on circuitry intended for much higher power? Lose a ton of efficiency? Change the strobe timing?

If anyone else knows a solution to mimic the cheap strobing rechargeable taillights, I'll be glad to learn!
July 2019 first build: 2009 Giant Trance X3 with stock BBSHD 52V
Next build: Just bought used 2009 Giant Trance X4, likely BBSHD also, maybe hotter controller/battery, undecided
Lots of other fun toys: Wildcat X, Xtrainer, 1978 KE100, Hypermotard 1100

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amberwolf   100 GW

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Re: Hard wired 6V tail light, I want it to flash constantly, how?

Post by amberwolf » Jan 05 2020 9:04pm

jpacadd wrote:
Jan 05 2020 8:47pm


Not a big fan of the 555 timing options either, sounds slow and lazy for my purposes.
you can make them flash faster tahn you can even see is flashing, if you like. look them up and you'll see. it's a cheap and versatile chip and simple to use. just that it's completely diy and will be something you have to install inside a casin g somewhere, to keep it out of the weather.

Maybe you're right and my best bet will be to buy yet another standalone rechargable bike tail light and try to adapt the PCB inline permanently. I don't want to permanently mount that because it requires independent charging, and I'm looking for simple.
if it's rechargeable, and takes 5v to do it, you just wire the 6v output of your system thru a diode or two like 1n4001 into a usb cable to plug into it. that would probably be sufficient, as long as it doesn't take more power than the 6v output can handle (but same is true of every other light you would run off the 6v).

if it's not rechargeable then it's probably a 3v light,using either two aa or aaa batteries, or a single cr2032 or similar. so you'd need to drop the 6v even more, or run two lights in series if tehy'll operate that way.

if it uses 3aa or aaa batteries, the diode trick works ok, 3 in series would probably work. if it's two cr2032 /etc watch bateries then thats 6v and would proably run right off your 6v output.

Thinking maybe I can adapt some wigwag module, but the power seems much higher and 12V. What happens if I try to run a 12V module at 6V on circuitry intended for much higher power? Lose a ton of efficiency? Change the strobe timing?
generally a unit meant for higher voltage simply wont' run at all below a certain voltage. how it behaves at voltages above that but below 12v depends on the specific design; you'd have to test to find out.

if it was just a light, no active electronics, it'd just be dimmer and dimmer the lower the voltage gets until it's just not enough to light it up visibly at some point.

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Re: Hard wired 6V tail light, I want it to flash constantly, how?

Post by TommyCat » Jan 06 2020 10:01am

Hi jpacadd,

I've been looking at this multi-programmable timer relay for different projects. (haven't got one yet...) That I think may work well for what you want to do... can handle 6vdc, flasher settings, up to 5 amps. (10 amp one available) If the cost is acceptable. :?

Link to product...

https://www.amazon.com/dp/B015Z2EQCU/?c ... _lig_dp_it


Link to manual...

http://docs.timersshop.com/Multifunctional_TimerV5.pdf

Look it over and see what you think.


Regards,
T.C
See my completed Magic Pie V5 rear hub E-Bike build Here!

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jpacadd   10 mW

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Re: Hard wired 6V tail light, I want it to flash constantly, how?

Post by jpacadd » Jan 06 2020 6:38pm

Thank you Amberwolf and TommyCat.

Tommy that looks great and also compact, I'll definitely look into it more.

Only thing in my way is now I put it all back together and tied down some nice wire runs including a fuse, all taped heavily with rubber tape, so not sure which I prefer, flashing light or not repeat disassembly and reassembly. Thanks though, I think I'll likely grab one of those. I have no problem with paying $20 for flashing, but couldn't help but notice the same product for $17 lower on the page :)
July 2019 first build: 2009 Giant Trance X3 with stock BBSHD 52V
Next build: Just bought used 2009 Giant Trance X4, likely BBSHD also, maybe hotter controller/battery, undecided
Lots of other fun toys: Wildcat X, Xtrainer, 1978 KE100, Hypermotard 1100

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wturber   10 MW

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Re: Hard wired 6V tail light, I want it to flash constantly, how?

Post by wturber » Jan 06 2020 11:50pm

amberwolf wrote:
Jan 05 2020 9:04pm
jpacadd wrote:
Jan 05 2020 8:47pm


Not a big fan of the 555 timing options either, sounds slow and lazy for my purposes.
you can make them flash faster tahn you can even see is flashing, if you like. look them up and you'll see. it's a cheap and versatile chip and simple to use. just that it's completely diy and will be something you have to install inside a casin g somewhere, to keep it out of the weather.
Yep. I used one about 30 years ago to make my prototype "strobo-yo" yo-yo. The idea was that you'd get fun stroboscopic effects from the flashing LED. As I recall, one of the main promoted uses of the 555 timer was to reduce the power consumption for apparently steady on LEDs. When flashed quickly they pulled less current. The LED on my strobo-yo would look steady on until you threw it. I used a potentiometer to vary the rate of flashing to get different effects. I'm no electronics guy and I managed this project without much trouble.

Fun fact - alkaline batteries are inherently unbalanced when installed in a yo-yo. Best to use non-alkalines. :^)
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aroundqube   1 kW

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Re: Hard wired 6V tail light, I want it to flash constantly, how?

Post by aroundqube » Jan 07 2020 1:00am

With a constantly flashing light, there is a chance of triggering an epileptic seizure , or other unpleasant reaction. https://www.epilepsysociety.org.uk/phot ... e-epilepsy

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Re: Hard wired 6V tail light, I want it to flash constantly, how?

Post by TommyCat » Jan 09 2020 4:49pm

jpacadd wrote:
Jan 06 2020 6:38pm
I have no problem with paying $20 for flashing, but couldn't help but notice the same product for $17 lower on the page :)
Dang, isn't that just like amazon. Thanks for the heads up! Lifetime warranty and made in the USA... still rubbing my eyes. :o
See my completed Magic Pie V5 rear hub E-Bike build Here!

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jpacadd   10 mW

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Re: Hard wired 6V tail light, I want it to flash constantly, how?

Post by jpacadd » Jan 09 2020 8:24pm

TommyCat wrote:
Jan 09 2020 4:49pm
:o
Anyway thanks for the heads up, I just pulled the trigger on it. Now just need winter to end! :lol:
July 2019 first build: 2009 Giant Trance X3 with stock BBSHD 52V
Next build: Just bought used 2009 Giant Trance X4, likely BBSHD also, maybe hotter controller/battery, undecided
Lots of other fun toys: Wildcat X, Xtrainer, 1978 KE100, Hypermotard 1100

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