Re: Blu-ray with boost driver in pointer form
flogged said:
[quote author=rkcstr link=1206263457/0#7 date=1206579117][quote author=flogged link=1206263457/0#4 date=1206420082]I take it you could run it off a single Li cell? I'd take one, possibly two of them for my next bluray project
What current range is the pot adjustable through? .. One other question, is it 'slow start'?
Hey, sorry, I actually responded to your post, but then accidently deleted it, meant to reply again later, but then forgot :-/
Anyway, yes, it could run off a single Li-ion, 3.0 or 3.6 should be fine. The input voltage just must be lower than the output (otherwise it wouldn't be boosting it
![Wink ;) ;)](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f609.png)
), but I'm not entirely sure of minimum difference of output to input necessary.
The pot doesn't really set the current, more so it drops excess voltage and limits current. Basically my aim was to be able to adjust for variance among the blu-ray diodes in forward voltage (using actual regulated current at 40ma, I had some running at anywhere from 4.3V to just under 5V). You can theoretically drive the blu-ray as high as it will draw at 5V by turning the pot to 0 ohms (but not recommended), or you can turn it up all the way and the output will probably be somewhere within 25-35ma, depending on the diode.
And, the regulator has a built in 2ms soft-start as well as there being an output capacitor to absorb any transients.[/quote]
Great work - I'm very interested. Would you be willing just to sell the SMD parts along with the schematic? I'd like to build a slightly smaller version of what you've got. For my next BluRay I'm going for a very small sexy pointer. I'm thinking something powered by a single CR2 battery, and your boost driver would work perfectly.