Any low power driver boards? Say 300mah MAX?

[KDOG3]

I have some experimenting to do and I would like to find a driver board that only runs at 250 mah, maybe 300 MAXIMUM. I want to drive a Seoul P4 so it is about 60-ish lumens output. The lowest one at the shoppe I saw was 350. Thats' too much. Any suggestions?

 

[Tritium]

I have some experimenting to do and I would like to find a driver board that only runs at 250 mah, maybe 300 MAXIMUM. I want to drive a Seoul P4 so it is about 60-ish lumens output. The lowest one at the shoppe I saw was 350. Thats' too much. Any suggestions?

The shoppe did allow you to choose the resistors on the MadMax for whatever current you want. I have one set for 150ma to drive 4 die 5mm leds.

Thurmond

 

[KDOG3]

Well I configured a GD buck boost for 250ma so that looks like it will work. I wonder how much runtime a primary CR123 will provide at that draw?

 

[shiftd]

Hi KDOG3,

GD250 is probably about 85-90% efficient, and CR123 primary has 1350 mAH.

Assuming your SSC has 3.4 Vf, we can do the following approximation

Pout = P in
250 mA * 3.4 = 85% * 3V * Iin
Iin = 333 mA

Now, to get runtime, divide the capacity with Iin = 4 hours.

4 hours is an approximate figure. In real life, we have the battery resistance loss,
Vsag under load, converter unideality, Vf variation etc.
So we can safely assume 3 hours of continuous runtime. 3.5 hours is also likely.