bFlex questions

Some questions about the bFlex:
1. What's the flashing mode (for bikes) like?
2. How do you program it to select different modes, voltages, etc.? Via the switch?
3. Am I right in thinking it would drive 2-3 3W LEDs from 4 AA's?

Thanks!
Ari

gsk3 said:

Some questions about the bFlex:
1. What's the flashing mode (for bikes) like?
2. How do you program it to select different modes, voltages, etc.? Via the switch?
3. Am I right in thinking it would drive 2-3 3W LEDs from 4 AA's?

Thanks!
Ari

Click to expand...

It's all in the manual. It can be found at

www.taskled.com

Mac

1. Don't know yet, maybe somebody that has one can answer this.
2. Read the Manual here it's the best way to learn about these drivers.
3. Nope, you could run one LED from 4 AA's, 2 or 3 LED's requires a FatMan or MaxFlex boost regulator.

Hope this helps

Later
Kelly

Thanks for the manual pointer. Somehow managed to miss that on the site.

Sway said:

3. Nope, you could run one LED from 4 AA's, 2 or 3 LED's requires a FatMan or MaxFlex boost regulator.

Click to expand...

Is the limitation the AA's? There's a table in the manual that seems to indicate it could work with 2...

Driver Configuration- 1 to 2 5W LED
Input voltage for regulation (min)- ΣVfn+1.1V
Input voltage Operating (min)- 4V
Input voltage (max)- 24V

Am I reading it wrong?

Thanks,
Ari

gsk3 said:

Thanks for the manual pointer. Somehow managed to miss that on the site.



Is the limitation the AA's? There's a table in the manual that seems to indicate it could work with 2...

Driver Configuration- 1 to 2 5W LED
Input voltage for regulation (min)- ΣVfn+1.1V
Input voltage Operating (min)- 4V
Input voltage (max)- 24V

Am I reading it wrong?

Thanks,
Ari

Click to expand...

I use the bFlex for 3 Crees running 1A on 4x18650 Li-Ion. I dont know about whether AAs will work -- is there a limitation on current with AAs?

Don't forget that the bFlex is a buck regulator so the input voltage needs to be above the total Vf of the led(s) to stay in regulation. The manual also mentions a minimum input voltage of 4V. So like others have said here you'd need 4AAs for just one led.

If you ran AA's you would need to run 12AA's in series for 3 LEDs...4 LI-ion a better option...as the more cells you run in series, the more problem with 'cell balancing'...

'strobe mode' goes ...dim, bright, dim, bright, dim ect...about 2 times every second...& there is High & low strobe mode...

once you get use to it, it is quite easy to program...

I use them in all of my lights...very nice driver indeed...

Hm. Thanks for all the info guys. 12AA's really isn't feasible for what I had in mind. The flashing mode sounds good though. Is there a boost puck in the same price range that has a flashing mode? I looked at the nFlex, but it looks like almost the same thing as the bFlex (incidentally, what's the difference?).

Ari

The uFlex is also buck, but says it can handle 2 LuxIII's in serial. I assume same problem though (min input voltage is 3V, so I'd be ok with alkalines but not NIMH)....

Ari

gsk3 said:

The uFlex is also buck, but says it can handle 2 LuxIII's in serial. I assume same problem though (min input voltage is 3V, so I'd be ok with alkalines but not NIMH)....

Ari

Click to expand...

In order to run 2 Lux 3's in series you would need a minimum of 5 AA cells.

3 Watt LED's voltage is around 3.3v

You battery voltage needs to be higher than your combined LED voltage.

So

1, 3W LED you would need a battery input of over 3.3v minimum idealy you would want much higher as the light will no be in regulation once you battery's drain past 3.3v

2, 3W Led 6.6v
3, 3W Led 9.9v

Understand?

BTW this is for the Bflex, Nflex, and Uflex. This is how all buck drivers work.

Mac

gsk3 said:

Hm. Thanks for all the info guys. 12AA's really isn't feasible for what I had in mind. The flashing mode sounds good though. Is there a boost puck in the same price range that has a flashing mode? I looked at the nFlex, but it looks like almost the same thing as the bFlex (incidentally, what's the difference?).

Click to expand...

The nFlex and bFlex are exactly the same (the latest version, that is), the only difference is their formfactor. The bFlex is round, nFlex is rectangular.

gsk3 said:

The uFlex is also buck, but says it can handle 2 LuxIII's in serial. I assume same problem though (min input voltage is 3V, so I'd be ok with alkalines but not NIMH)....
Ari

Click to expand...

You'd be ok on the input voltage, but to drive two LuxIII in series would require more like 8+V. Also, alkalines dont like high currents, and their voltage drops pretty quick into the 1,2V range. You'd be better off with NiMH/NiCD's.

But what is it you're building? Ie what emitters and how many of them? And what is the batterypack you'd like to use? With answers to those questions we can give you better advise.
And like the rest before me said: the bFlex is a really, really nice driver. The new bikeUI is pure genius-ness (i'm pretty sure thats not a word).

Yeah, got it. That's why I was wondering if there were a boost device of similar quality to the (buck) bFlex.

I'm trying to build a helmet-mounted front/rear flashie light. Ideally it would have a 5W white spot in the front in steady mode and a 1-3W red wide-angle in the back , driven off a common 4AA battery pack. If they both have to flash, then they both have to flash; that's ok. I have the physical mounting side mostly worked out, but finding the right drive device for the electrical side has me puzzled. I'd rather have a real solution than just attach a resistor to bump the voltage up (assuming 2AA's per front/back).

Priority goes to brightness, not to run-time. Just need it to last an hour or so.

Ari

The Vf of a 5W is higher than a 1W/3W luxeon (~6V or more), you might be better off substituting an SSC or Cree led for that, more efficient and the Vf is closer to a 3W luxeon for the same drive current. Even then you'd still would not be able to drive them in series with a buck driver like the bFlex, etc..,...
.. Georges Maxflex isn't quite ready yet and you want flashing so I guess that leaves out the Fatman and Shark drivers boost.

Maybe wire the leds each with their own bFlex ie., in parallel(?) but you would have to buy 2 drivers. Another alternative is to use 3AAs and 2xFlupic - if you don't mind them flashing together you might be able to use 3AAs and a tri-flupic and only use 2 of the outputs (you would have to verify that with goldserve) :thinking:
btw:The flupic isn't true regulation but you may not notice the difference in the real world and the gradual drop-off might be nicer for biking applications

Perhaps others can pipe up with other (better) ideas. How much current are you planning to put into the leds?

Another note: I don't know if its a problem but can you run a white LuxIII and a red one on the same series string? I'd say yes with a constant current driver, but the difference in Vf is pretty big actually. My guess is that it should work ok, but can someone verify that?

Totally fine going with Seouls or Crees if it helps. My brother has access to a CNC machine shop, so whatever the hardware needs to match it will match.

Would rather avoid buying two bFlexes. Starts to exceed the budget pretty quickly. I don't mind them flashing together. What's this MaxFlex of which you speak?

The power source has to be either 2xAA or 4xAA. It's a silly thing to be anal about, but I hate odd numbers of rechargeables, and most chargers, including good ones like the Maha I have, only charge in pairs. Managing a rotation schedule is not my idea of fun.


The red vs. white different voltage issue didn't occur to me. I'll look into it.

Thanks again,
Ari

It's kind of the boost version of the bFlex (same creator): Maxflex

but there have been a few issues on the firmware that are currently being debugged so it won't be ready for a while. I also don't think the first iteration has a flashing mode. The current status is discussed at the end of this thread: Maxflex THread

I can appreciate your feelings about odd number of cells - I'm a little like that as well. Depends on how long you can wait - the flupic or tri-flupic is available now but 4AAs is too much voltage for it (I think the upper limit is 5V). You can trim the input voltage with a resistor but that seems like a waste of energy. Are you trying to keep the number of cells to no more than 4AAs to keep the weight down (helmet mounted pack)?

So looks like MaxFlex would be what I want but not yet.
4AA's is both the number of cells that my charger accepts as well as a nice maximum for a helmet-mounted light. Plus it's a standard size for battery holders, etc. etc. 2AA's would work fine too. I guess two Flupics might work, but at $40/ea that's not really an option.
Ari

PhotonAddict said:

It's kind of the boost version of the bFlex (same creator): Maxflex

but there have been a few issues on the firmware that are currently being debugged so it won't be ready for a while. I also don't think the first iteration has a flashing mode. The current status is discussed at the end of this thread: Maxflex THread

I can appreciate your feelings about odd number of cells - I'm a little like that as well. Depends on how long you can wait - the flupic or tri-flupic is available now but 4AAs is too much voltage for it (I think the upper limit is 5V). You can trim the input voltage with a resistor but that seems like a waste of energy. Are you trying to keep the number of cells to no more than 4AAs to keep the weight down (helmet mounted pack)?

Click to expand...

I thought Flupics were closer to $20/ea? I recall reading somewhere that the tri-flupic is ~$30 but I'm not sure and can't find the thread at the moment. Would be best to contact goldserve to confirm.

gsk3 said:

So looks like MaxFlex would be what I want but not yet.
4AA's is both the number of cells that my charger accepts as well as a nice maximum for a helmet-mounted light. Plus it's a standard size for battery holders, etc. etc. 2AA's would work fine too. I guess two Flupics might work, but at $40/ea that's not really an option.
Ari

Click to expand...

Website I saw looked more like $40. I'll double-check.
Ari

PhotonAddict said:

I thought Flupics were closer to $20/ea? I recall reading somewhere that the tri-flupic is ~$30 but I'm not sure and can't find the thread at the moment. Would be best to contact goldserve to confirm.

Click to expand...

Take a look at this thread for info and contact him for details: FluPIC sales thread
I think this is the latest version of the firmware: FluPIC v2.2 firmware

I will be ordering another one soon but will probably ask for a simpler, custom interface (extra charge).