I'm putting together a mid-tier gaming PC and I want to mount a figurine inside it that has a built-in white LED powered by two LR44 batteries. I'm considering connecting this LED to a 4-pin molex or an ARGB header, but I'm worried about the voltage. The LED needs about 1.8 to 2 volts to run, while both molex and ARGB can supply 5 volts. Could this higher voltage damage the LED? I want to avoid burning it out and potentially damaging my PC. What would be the best way to wire it up? Can I just connect it to the battery terminals, or do I need to include a resistor?
4 Answers
You can easily figure out the resistor needed for your setup using a resistor calculator. Just input the forward voltage (which is around 2V for your LED) and the current rating. If you’re going with 5V from molex, a resistor between 130-200 Ohms should work well, but double-check the values based on your specific LED's specs. Just be careful to avoid the 12V pin—it's a surefire way to fry the LED!
Definitely use a resistor! Doing the math with Ohm's Law is key to finding the right resistor for your circuit. For example, if your LED pulls 10-30mA, you'll want a resistor that can handle that—keeping heat in mind is also crucial. If you're running it at 12V, just adjust the calculations accordingly.
Remember that LEDs can get damaged easily without a current limiting resistor, which is crucial to ensure a steady flow of current. You can calculate your resistor value by subtracting the LED voltage from your supply voltage, then applying Ohm's law to get the resistance. It's the difference that limits the current through your LED, or else you risk burning it out. For a 5V supply, make sure to cover the calculations for the best results.
If you're using a molex, you actually have a 3.3V option available, which should work well for your LED. Don't forget to add a small resistor just to be safe! For the battery compartment, you can connect wires directly, but I recommend using a connector for flexibility in case you need to disconnect it later.
Thanks for the tip!
Appreciate the link to the calculator!