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Thread: b2flex

  1. #1
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    b2flex

    As some of you are aware, I've been working on getting a 1.5A bFlex driver into production. It has been in the hands of my assy house and they are getting closer to having boards ready - PCB's should be in their hands soon and they have a bunch of components already ordered etc. I'm hoping to see finished boards in <3 weeks.

    So, here's a couple of pics (top & bottom view) or the prototype. Obviously the production boards will be solder masked & silkscreened. The blue wire and a little surgery near the regulator (for the keen eyed to spot) is to work around a design bug in the proto - one good reason to proto a design before going to production





    As can be seen from the pics, I've deleted the onboard switch of the old bflex, not enough folk used it or wanted it. So, removing it gave be more room to provide some area for the thermal pad 'zone'. For <1A no heatsinking will be required, above 1A I HIGHLY recommend attaching the thermal area to a heatsink (similar concept to the maxflex).

    The heatsink requirements aren't as strict as for the maxflex since the b2flex is a buck driver and runs with less heat losses in the switcher IC. With the uC sitting right above the switcher (on the opposite side), thermal monitoring will also be more accurate and faster responding, so turning that feature on will help to protect the driver. Also, the switcher IC on b2flex has internal thermal protection as a final failsafe - though should not be relied on for continuous overtemp operation.

    Efficiency is on par with the bflex and switching frequency is 4 times higher, so that keeps components/inductors quite small for the 50% increase in output power capability.

    Board remains 1" in diameter with all solder connections points on the board periphery. Input and Output power connections now have larger pads at 0.050" hole diameters (versus 0.037" for bflex) and switch/stat holes are 0.040" diameter. This should ease the task of soldering thicker in/out wiring to the b2flex.

    Firmware is identical except the addition of two new current tables (1.2A and 1.5A). Reverse polarity protection and voltage/thermal monitoring is identical to bflex.

    Hope this answers some questions and gets folk exciting & thinking of new bike light projects now that summer is slowly winding down in the northern hemisphere

    cheers,
    george.

  2. #2
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    Nice job as always. May have to build another light...

  3. #3
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    Yes a Bflex at 1.5 A, to me that is asking for 2 parallel strings of leds. Something along the lines of 3s2p leds.... at 750ma

  4. #4
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    Quote Originally Posted by heatstroke
    Yes a Bflex at 1.5 A, to me that is asking for 2 parallel strings of leds. Something along the lines of 3s2p leds.... at 750ma
    Single XPG roadie light
    DIY LED Bike Lights:
    A few Dynamo builds and some Small battery lights

  5. #5
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    Quote Originally Posted by znomit
    Single XPG roadie light
    Built how?

    Sorry.... but do you mean 20mm, reflector or optic?
    And what housing?

  6. #6
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    Quote Originally Posted by ireland57
    Built how?

    Sorry.... but do you mean 20mm, reflector or optic?
    And what housing?
    Something stupidly simple, probably a regina reflector, magicshine battery.
    1.5A XPG is getting close to 500lm which is plenty on the road.
    DIY LED Bike Lights:
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  7. #7
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    Quote Originally Posted by znomit
    Something stupidly simple, probably a regina reflector, magicshine battery.
    1.5A XPG is getting close to 500lm which is plenty on the road.
    The more I thought on this the more I like it. Nice place for an overdue S2 (when are they coming?) Really, a singleton is the only place pushing 1.5 A through the XP-G makes sense. You can get more sturn for less drang with more XP-Gs at lower amps where they are more efficient, but the light will be bigger the optics more complicated, and the heat needs more management. At 1" for the diameter of the B2Flex the body needs 1" ID or more. A housing a bit over 27 mm in OD means 1.5" long would be ample cooling surface without fins, if the back end has a good thermal path. Suitable for a Culite in Cu or Al.

  8. #8
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    When George Announced the 1.5 amp Bflex this did get me wondering what a single XPG and Regina would be like driven harder .

    so here it is a Hipflex driving a single XPG R5 with a Regina .

    the Hipflex current tables go 1 amp 1.4 amps 2 amps
    so I took the 2 amp one and 5 level multimode for this trial

    starting at the bottom on dim
    and working up to the top @2000 ma drive but I am not sure what the drives inbetween are .








  9. #9
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    Quote Originally Posted by troutie-mtb
    and working up to the top @2000 ma drive but I am not sure what the drives inbetween are .


    Usually a doubling of current between steps so 1A and 2A seen above .
    From here this is 350 and 530 lm with 1.5@460lm, closer to looking like 2A.

    Im currently happy with under 400lm on the road with my dual dyno lights so think this will work great.
    DIY LED Bike Lights:
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  10. #10
    help with the zip please
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    George, any indication of cost?

    edit: $30, just saw it on your site

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    OK - FINALLY have got production boards on hand. Price has gone up a couple of dollars due to one key component being hard to get and having to pay a bit of a premium to source it.

    I've added 2 additional current tables to the original bflex, so you have a choice of:

    350mA/500mA/750mA/1000mA/1200mA or 1500mA. The rest of the firmware is identical to the currently shipping ui-uni2 so same as maxflex/h6flex/hipflex and d2flex.

    I've got some preliminary info up on my website, but will be adding more to the tech section over the next couple of days including the operating manual.

    Here's top & bottom pics of the new production boards.





    cheers,
    george.

  12. #12
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    Very nice George. Can't wait for these to arrive at Cutter.

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    Me and you both, in George's defence he has not had a lot of luck with his assembly house so hopefuly we can crank some sales to make up for the delays
    Cheers
    WeLight

    Cutter Electronics Pty Ltd www.cutter.com.au

  14. #14
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    Nice! Any word from the assembly house about the maxflex?

  15. #15
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    Quote Originally Posted by xyz-saft
    Nice! Any word from the assembly house about the maxflex?
    Just received 100 maxflex5A drivers this morning, so I'm going through my contact list of folk that emailed me over the past few months. I'm expecting more maxflex5a to arrive this week (500 are on order).

    cheers,
    george.

  16. #16
    help with the zip please
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    a question re programming

    Access into the programming menu seems much easier with the b2flex in comparison to the bflex units that have. I like that when you first connect the battery you have that intitial period of rapid flash to press and access the menu.

    The question I have is, once you have completely programmed the driver is it possible to turn of this flash period so that it doesn't occur every time you connect the battery? I ask because the twin DX light I just built is for a friend that has the ability to "just press buttons in the hope of getting to the light level she wants" and I can see her freaking out when the lights flash and inadvertently accessing the program functions?

    If it is disabled is there a way to get back into the programing menu at a later date should the need arise?

    Yes I know, it is difficult to make such a user friendly, highly customisable driver that is also idiot proof

  17. #17
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    Menu selection etc hasn't changed for several years (across all flex drivers), so not sure why you think it is easier on the b2flex versus bflex, unless you have a pretty old bflex (i.e. old firmware).

    Anyhow, if you want to remove the 'flash' sequence, just select UIB2Q (quiet version of UIB2).... With UIB2Q you get into the menu by holding the button down AS YOU APPLY POWER. So, that is likely more "idiot proof" for your lady friend.

    Oh, never hurts to re-read the (correct) manual a few times

    cheers,
    george.

  18. #18
    help with the zip please
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    Ouch George, I always RTFM, off to lick my wounds now

    OK, so maybe next time I should concentrate on not just reading the manual, yes it is the correct version, but also comprehending it. Straight out of section 7

    UIB2 and UIB2Q are functionally identical. The only difference between the two is whether or not the
    3 second menu window flash occurs. For applications that utilize a separate power switch to turn the
    driver on and off, the 3 second menu window flash can be annoying and so UIB2Q provides a ‘quiet’
    turn on. To access the menu system in UIB2Q requires pressing and holding the momentary action
    switch down while applying power since there is no “3 second menu window”


    Comprehending that this time, maybe it's better leaving it the way it is. If she knows not to touch the light while it flashes after connecting the battery then there is probably less chance of her accidently accessing the menu while trying to turn the light on in UIB2Q.

    Thanks for the heads up

  19. #19
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    I have to say UIB2Q is one of the most important differences between the bflex and b2flex for me, having built lights with both.

  20. #20
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    I have a late model Bflex (not B2flex) that I use in UIB2Q mode.

    I left it in UIB2 mode until I had made all the setting changes I needed, then changed it to quiet mode.

    Emu, I think there is much more chance of someone mucking up the settings accidentally by randomly pressing the button during the initial 3 second window than there is of them holding the button at the same time as connecting the power. Mind you, my light has a trailing lead and holding the button while plugging in is a bit of a contortion. I guess its easier if the power socket is built into the lamp. But you know her better than me.

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