What happens if? (direct drive LED)

I'm having a hard time finding a compact boost circuit for a 1xCR123A-powered LED.
I would ideally like a ~3.6V, ~450mA circuit board that is about 4.5mm thick. Induction coils are big!
Just as a frustrated experiment, I tried powering a SSC straight from a CR123 and it lit up at just a useable level.
What is the downside to running it that way as a complete build?

I asked myself the same question.
My guess is :
- very variable light output because battery voltage will drop slowly, but it will exit the optimal tension range of the led
- no control over current intensity in the led, did you measure it ?

try to get a low output flupic,
maybe PM member Goldserve

gearbox said:

I'm having a hard time finding a compact boost circuit for a 1xCR123A-powered LED.
I would ideally like a ~3.6V, ~450mA circuit board that is about 4.5mm thick. Induction coils are big!
Just as a frustrated experiment, I tried powering a SSC straight from a CR123 and it lit up at just a useable level.
What is the downside to running it that way as a complete build?

Click to expand...

Only downsides is that it will be very dim and will get dimmer as the cell gets spent. Also there will still be plenty of juice left in the CR123 at the point where the output of the LED is probably unuseable.

The upside is that it will probably run forever (I'm exaggerating) this way. OK, probably hours and hours. However, you can also get similar performance from a boost regulator set up to severely underdrive the LED the same way and get way more performance since it will be able to suck a lot of the power from a CR123.

As far as Flupic, a li-ion cell is better for the FluPic than a CR123. It probably won't even fire up the LED with a CR123 because of the LDO's drop out voltage.

The micropuck 400mA version would work. This driver is 1mm taller and pushes more power then you would like. I'm not sure how high this driver is.