To drive 2 LEDs, each with a forward voltage of 3.6V and a forward current of 700mA, from a 3S LiPo battery (which typically provides a nominal voltage of around 11.1V and can range from 9V to 12.6V), you will need the following components:
LED Driver IC: Look for a constant current LED driver IC that can drive the specified current $700\text{mA}$ and voltage for the LEDs. A buck (step-down) LED driver might be suitable since the battery voltage is higher than the LED forward voltage.
Inductor: Required for the LED driver, the value depends on the specific driver IC you choose.
Capacitors: Depending on the LED driver IC, you might need input and output capacitors to stabilize the input and output voltages. These are usually in the range of a few microfarads.
Feedback Resistor: This helps set the current through the LEDs if the driver uses a resistor to set the current level.
Protection Diode: Some circuits might require a diode to protect against reverse polarity or back EMF if using inductive components.
Heat Sink: Since you are driving LEDs at relatively high currents, make sure they are adequately heat-sunk to prevent overheating.
Here's a potential arrangement to consider:
LED Driver: A part like the LM3406 could be used. It is a buck regulator designed specifically for driving high-power LEDs.
Inductor and Capacitors: Follow the datasheet recommendations for the LM3406 for selecting the right inductance and capacitance values.
Make sure to check the datasheet for the specific LED driver IC you select for detailed connection schematics and recommended part values. This setup will efficiently convert the battery voltage to drive the LEDs at a constant current.
If you confirm any specific components or have any preferences, I can help further refine this setup!
gdk
copilot