simplest boost LED driver, please modify...

guys please try modify this simple boost LED driver to run bluray or red laser diodes, any suggestion and modification please reply on this thread.thanks

all i can suggest is to build it and test it on a couple of led's in series, measuring the voltage and current with an oscilloscope
I wouldn't trust it on a blueray without testing first

the author suggest to be careful driving led's with this circuit, this means you would have to be 10x more careful driving LD's
http://cappels.org/dproj/ledpage/leddrv.htm

i would expect the best you can do with that circuit, and please post the procedure on how test the voltage and current of that after you done that, then if you can modify it to drive LDs it'll be better to help other members here to how build a basic boost driver for LDs, i would say it was totally handmade boost driver and it'll be good to other members here if can modify it well, thanks.

is that a joule thief?

anyways, from what I can tell transformers are no good for driving sensitive laser diodes... the power they give off is really dirty.

I've thought about using something like that to boost up an AA battery to the input voltage for a proper driver, but you're limited to what current an AA can produce.

well, i just put this cct together. it does work indeed down to 0.6-0.7V with a white LED as load. the output is proportional to the input voltage, though - it is just not a regulator and I wouldnt use it for any sort of LD. Its params are also dependent on the inductor, so making a universal tutorial for everyone to build it with repeatable results would not be feasible.

i know you guys have more knowledge on electronics than me i believe there's such a way to drive LD from this bit. in my test the output of this on mine was 41vDC without load, and when you put load it only gives out what the LED voltage needed, the current of this in the out was 300mA without load from input of fresh 1.5v AA, when you put LED load on it, the current goes down from 250mA to 150mA, depends on LED type. i experiment a while ago about this, i combine DDL driver using this driver as an input, i tried first the IRLD here, it works well, the input i used to run this was single 3.6v CR123A, it was good i can light a match from the IRLD in seconds, im also doing my best to regulate more efficient from this simple driver, i hope you guys can put some knowledge here or some good modification instead of expected criticizing on what im thinking off, help is needed for this thread, its time to experiment, its time to used what everybody learns in this forum, i know lot of you guys have creative minds, thats why i believe that you can give a good modification for this setup, thanks.

i believe that we can solve and make things happen like we are exprimenting for a new LD,learning how to run in right voltage and current... something like that, all of you guys have patience and good heart for this so we can make this possible, on LPF there's no impossible if believe on it that things may happen in different ways..

it could work if you put a real regulator on its output following the enhanced example in woop's link. you should use a schottky rectifier or a fast recovery diode and..say...10-22uF filter cap and then, in the place of the LED, hook DDL's regulator or smth along the lines of LM7805 followed by a resistor (for low power bluray) or better yet low drop regulators, such as BA05T or LM2931 (<100mA) for better efficiency.

i saw this a while back, I made one, I personally thinks its only good for LED's as they pull low current, not reds, BR's maybe but i woulndt suggest it and the output wont be stable

phenol said:

it could work if you put a real regulator on its output following the enhanced example in woop's link. you should use a schottky rectifier or a fast recovery diode and..say...10-22uF filter cap and then, in the place of the LED, hook DDL's regulator or smth along the lines of LM7805 followed by a resistor (for low power bluray) or better yet low drop regulators, such as BA05T or LM2931 (<100mA) for better efficiency.

Click to expand...

even after all that the efficiency would probably be pretty crappy

yes the driver maybe wont have a stable output, but using our creative minds we can made that possible for LDs like Phenol said i can use it as an input for some sort of good regulators like i was using DDL driver, i already tried it using IRLD, it works really well using single 3.6v of CR123A as input for simple boost driver then following on its output was DDL driver. I put DDL driver for higher  resistance, discharge the caps, and then put IRLD on DDL driver output, run the  simple boost driver the turn the trimpot into its right resistance, and IRLD runs quite good lights a match well. So if theres anyone here with much better idea to modify this and turn it as laser driver it would be much better for everybody specially for new members here.

of course 3.6v is gonna power an IR LD thats not gonna boost up at all like that.

Please, no one puts yours LD direct to this Boost Driver. I put a IR LD and it burnned, (COC?). I knew that it could happen.

in this driver probably you cannot put LD directly, thats why im saying here that is needed for modification, we need to work out our brain here, my IRLD has 1uf Capacitor and reversed 1n4001 Silicon Diode across its legs and 10ohm resistor was attached on IRLD Positive leg in series before i put it in this boost driver and the driver has 10uf capacitor across its output terminal, thats why i ran it with no problem, Inductor was designed as 100 turns center tapped (50/50 turns) using #32 magnetic wire around small Bobbin core i have.

this circuit is meant to drive 3v LED's off batteries that have less than a volt left in them, and it does that well... but LEDs are pretty sturdy little devices which require nothing more than a resistor to prevent thermal runaway... they handle voltage spikes and other spurious power pretty well, so designing a crude circuit to bump up the voltage isn't going to hurt them. Laser diodes, however, are much more fragile and sensitive, and would likely be killed in an instant by a joule thief. [edit: I see it already has...]

As far as using one of these to step up the voltage to feed a proper driver goes.. yeah, that might work, but there are single integrated chip solutions you can buy for under a buck that sure beat wrapping some wire around something metal and hoping for the best. guessing inductance and hand winding toroids is not a way to drive your delicate and expensive laser diode.

by this time im just trying to use the boost driver to ran DDL's driver and regulate the current, i think this is one of the best option i can do for now, im trying to test it first before the actual connection of LD, if the DDL regulates the current coming from the boost driver this might be one solution, just please help me guys to test this boost driver to ran DDL driver, if so please give me some guide on how you test it, thanks.