I want to power 25 adafruit NeoPixel LEDs. According to the specs they draw a maximum of 60mA at 5V each. In total that would be 1,5A at 5V.
I would like to use a 2A usb phone charger as a power supply for the LEDs. If I cut open an old usb cable, there should be 2 power lines in there. I would like to use those to power the LEDs.
Is there any reason that an usb phone charger should not be used as a power supply?
Is there any reason that this is a bad idea?
Thank you very much for your advice!
Best Answer
Given that you at looking to use it at 75% of it's rated capacity, you should be good to go. USB chargers are ubiquitous as basic 5V switching supplies.
It will work, given you buy a decent/reputable usb charger and not a cheap knockoff of questionable quality. A decent charger will have proper isolation between the mains side and the dc output, as well as safety features like a fuse or Over Current Protection. A cheap one may not actually put out 2 Amps.
Keep in mind that some chargers will put out slightly more than 5V, to make up for power loss over the cable. This would benefit you. You want to use a quality cable as well, with thicker wires. Cheap wires may use aluminum instead of copper (or copper coated aluminum) and of a smaller cross section, resulting in higher power loss at higher distances/current.