Hi, I'm building a laser/led combo powered by two 14500 rechargeables (8.4v peak in series).
There's one central board (2.25" x .75") that has a switch and both drive circuits on it.
My plan was to use DDL drivers for both the laser and the led.
The laser takes 25 - 70mA at 1.8 - 2.5v, so I chose an 18ohm resistor & a 50-ohm pot for that DDL.
The LED takes 600mA (at ~1.7Vf). I can use a 2ohm resistor and a 50ohm pot for that DDL.
BUT!
If P = (Vs-Vf)*I,
the power dissipation of the LED circuit would be as high as (8.4 - 1.7)*.6 = 4 watts!!! Can that be right?!?
I really like the DDL because there's so much good info on how to use it, and I already have the parts I need to build them (still waiting on breadboard and protoboards).
But now I'm thinking that I need to find a more efficient option for driving my LED.
I'm open to advice, recommendations, or corrections. Thanks!
There's one central board (2.25" x .75") that has a switch and both drive circuits on it.
My plan was to use DDL drivers for both the laser and the led.
The laser takes 25 - 70mA at 1.8 - 2.5v, so I chose an 18ohm resistor & a 50-ohm pot for that DDL.
The LED takes 600mA (at ~1.7Vf). I can use a 2ohm resistor and a 50ohm pot for that DDL.
BUT!
If P = (Vs-Vf)*I,
the power dissipation of the LED circuit would be as high as (8.4 - 1.7)*.6 = 4 watts!!! Can that be right?!?
I really like the DDL because there's so much good info on how to use it, and I already have the parts I need to build them (still waiting on breadboard and protoboards).
But now I'm thinking that I need to find a more efficient option for driving my LED.
I'm open to advice, recommendations, or corrections. Thanks!