Alright. I have a headset, a Turtle Beach X41. 2.4ghz wireless for audio, and is powered by 2 x AAA batteries.
This headset was chewing through 4-6 batteries a day, so I decided to power it with a usb wall wart and some lightweight wire.
I created a voltage divider, 5v in -> 100 ohm resistor -> 3v -> 150 ohm resistor -> ground
worked well, got about 3.16 volts. close enough.
now, I was trying to power it from the 5v from a usb cable. plugged it into my laptop, checked it with the meter, 3.16v
I used some alligator clips to clamp to the contacts, and..... nothing. I figured that the usb port wasn't providing enough juice.
I hooked my contraption into the 5v rail of my 3d printer's power supply. still nothing.
just to make sure I wasn't going nuts, I hoked my alligator clips to a battery holder with the 2 x AAA batteries, and it worked fine.
I must be missing something here. What am I doing wrong?