I want to power a 5V white LED strip (50cm) from an Arduino (Leonardo, connected through long USB cable to my PC permanently). The idea is to have the LEDs dimmable through the Arduino pwm signal. I have trouble getting enough brightness from the strip.
- When I connect the strip directly to USB I measure 300mA and get full brightness.
- When I connect the strip to the Arduino output I measure 30mA and brightness is way too low.
- When I connect the strip to a ULN2803A Darlington driver (connected to Arduino VCC (4.6V) and output) I measure only 18mA
- When I connect the strip to the ULN2803A but to an additional 5V USB I measure 95 mA and get a brightness that would be acceptable for my purposes but requires an additional USB connection which I would like to avoid.
Browsing on internet (I'm just a hobbyist) I got the idea to use a boost converter to get a higher voltage on the LED strip. Would that be a good idea or are there simpeler ways to get more brightness?
LED strip data: 3528 SMD 30LED power consumption 4W/m (I use 50 cm)
The reason for me to think about a boost converter was because the USB is 5V and the Vin of the Arduino is 4.6V so I thought that this difference could be the problem.