HDDs are the most common type of storage device in modern computers, and are also used in many other devices, including. A hard disk drive (HDD) is a data storage device that stores digitally encoded data on rapidly rotating platters with magnetic surfaces.
In the end, the RESISTOR determines how many volts the LED circuit needs to work, the LED itself has less influence than you might think. Best Buy customers often prefer the following products when searching for led hard disk. If there's no resistor, there will be no limit on the current and the LED will go up in smoke from the massive current spike. The resistor determines the amount of current using Ohm's law and the input voltage. So if you were to directly connect a white LED to a 12v supply, where does the extra 8.9 volts go? It has to be dissipated by a resistor. You have to look at the whole circuit with LEDs.
That's what I mean when I say they don't run off of a voltage- what matters is the current. Since you can't change the voltage going through the LED, you have to set the brightness by the amount of current flowing through it. So when you measure the voltage across the leds of the LED when its on, it will always be 3.1 volts. Ugh, I guess you could say that they do have an exact voltage.ĭiodes have a specific voltage drop when they are conducting- with white LEDs, this is about 3.1 volts. How more current translates into actual light depends on the datasheets (and your eyes, which are more sensitive to green light than blue). So pretty much any LED between 2V and 5V should work. Knowing this you can do some maths and work out with a 2V LED, you'll get 9 mA. This LED works in a range of 1.7V to ~2.1V. Here are some example specs for a Red LED from Kingbright. You need to look up the datasheet for the LED you want to use. Luckily the motherboard has this resistor built into it. You need a resistor because LEDs have low internal resistance and you don't want a huge amount of current flowing in the circuit.
#SHOULD THE HARD DISK LED BE ON DRIVER#
Unless the supply is a constant current LED driver (which is not the case for your power light), there needs to be a resistor in the circuit. More current means the LED will be brighter. The higher the voltage across the LED's pins the more current will flow through it. So the 12V LED from Ebay you linked to aren't going to work.
#SHOULD THE HARD DISK LED BE ON SERIES#
See,īut I also think there is a resistor in series to limit the current (330 ohm). I think the output is 5V from the motherboard header.