Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. It only takes a minute to sign up.
Sign up to join this community
I'm a beginner in this field. I'm making a desktop LED Sign, for that I'm using a 12V LED Light Strip. I have a standard USB Cable from an old phone charger, it says 30V on the cable, so if I connect that cable to the LED, and power it from a USB port on my PC, will the LED break or get ruined?
Also another question, on the right side, it says +12V so does that make a difference if I power it through a 30V cable?
USB ports (usually) output 5V. The "30V" on the USB cable just means that the wire is rated for 30V, not that it will actually supply that voltage.
So, in short: no. If your LED strip needs 12V, you need to connect it to a 12V power supply, not a USB port.
You need 12V,0V and Logic Data in DIN to address the serial data chip. There is a separate 0V for DIN.
As @dandavis suggested in the comments, if you really want to power it from USB, you can get a 5V->12V step-up converter to get 12V from your USB supply. Keep in mind that current goes down as voltage goes up (so if your supply is rated 5V @ 1.2A, you'll get less than 0.5A at 12V from a converter).
For that small strip of LEDs you show, this should be sufficient, but do not try to run a six-foot length of that stuff off your computer's USB port -- your computer is gonna have a bad day (in all probability the strip just won't light, but you could pop an internal fuse on your USB port, which may or may not be self-resetting; if it's not, hopefully it's a discrete component that can easily be replaced by someone with the proper electronics/soldering skills).
Keep in mind that this particular LED strip has a microcontroller (the little black chip) and a DIN line, as Tony mentioned in his answer, so how it behaves without data on the DIN line is anyone's guess. The strip may not light at all, or (and I'm assuming this is your goal) it may just come on full brightness with no control, which isn't a terrible thing in and of itself.
