Design of two drivers for a DV-S9 type diving flashlight OSHW

[luicer]

Hello everyone,

I want to share with you the design of two drivers for a DV-S9 type diving flashlight. The complete design documentation can be found on my blog: https://luicer.github.io/categories/#led-flashlight

The first driver is of the linear type and supports a current of up to 3A with an efficiency of up to 70% at maximum supply voltage (4.2V), the second driver is switching type and supports up to 1A with an efficiency independent of the supply voltage of 85%.

The PCB has been designed for the aluminum housing of the flashlight and is easily interchangeable.



The measured efficiency for the linear driver as a function of the supply voltage is as follows:


The measured efficiency for the switching driver is as follows:


If you have any comments, let's discuss them.