I'm having trouble understanding Current Draw as it relates to Ohm's Law (V = IR).
I have a power supply rated at 5V and 500mA. I'm trying to power a string of LED lights. According to my datasheets, each LED draws ~50mA of current. If I have a string of 5 LEDs, that would draw 250mA. If I have a string of 10 LEDs, that will draw 500mA of current.
Here's my problem:
According to my understanding of Ohm's law, Current = Voltage / Resistance. As I understand it, when I add additional LEDs to my circuit, each LED should contribute resistance to the circuit. If this is the case, according to Ohm's Law, I would expect that current would DECREASE with each additional LED. In other words, as Resistance increases and as Voltage stays the same... when I divide V by an increasing R, this equation results in a lower I.
Instead, it is INCREASING!
Am I misunderstanding something here?
Yes, I was misunderstanding something there. The LEDs on my LED strip are wired in parallel, not in series. Resistances wired in parallel lower the total resistance through the circuit, so current would INCREASE coming from my power supply.
Additionally, LEDs don't function exactly like a regular resistors. As Voltage increases, current increases non-linearly, so Ohm's Law cannot apply perfectly.