Bleeder resistor on BLF A6 driver?

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throwton
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Bleeder resistor on BLF A6 driver?

Hey guys, just looking for a little insight about one of my recent projects.

 

A few weeks ago I designed a FET tailcap board for my Astrolux S1, which uses an FET instead of a physical switch to switch the light on and off. As many of you probably know, the challenge is somehow getting usable power to the FET so that it can stay on. I decided to use a mini supercapacitor as the energy storage mechanism, thinking I would just add a bleeder resistor across the driver which would keep the capacitor charged while the light was off. However, as I understand it, bleeder resistors can mess up the mode timing on some drivers. Does anyone have a schematic of the BLF A6 driver, and, if I add a bleeder, will it mess up the timing?

 

Schematic

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DrafterDan
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Look in the thread for the lighted tailcap project by PilotDog68. They talk about the bleeder resister and it’s affects on a similar driver. I made mine a while back, so haven’t really been keeping up on it.

~D

have light, will travel

RotorHead64
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Put your bleeder on top of C1. Start with 600-700ohms. If the the mode timing gets out of wack then drop the resistance. The lowest resistance bleeder I've used was 480ohm iirc.

This may be totally off base for your application though.

throwton
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RotorHead64 wrote:

Put your bleeder on top of C1. Start with 600-700ohms. If the the mode timing gets out of wack then drop the resistance. The lowest resistance bleeder I’ve used was 480ohm iirc.


This may be totally off base for your application though.

Thanks for the advice. I’m still in the process of putting it together, but I’ll definitely try that.

I've only been wrong once, and that's when I thought I was wrong.

Lexel
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if you fail with the A6 driver the Bistro HD OTSM drivers have absolutely no problem with bleeders as they dont use an OTC

basically you need a Attiny 25V and a special tantal capacitor with some other resistor and C1 values to make any FET+n+1 or FET+1 driver work with it