Are you sure it's 12V? If the voltage is higher than 12V, that could be the problem. Also, it would help to know what LED strips you're using. Are you sure they are 12V?And, regarding power, and power dissipation, there's another formula: P=IEEasy to remember because it spells "PIE" And, when you combine the two formulas -- Ohm's Law and this power formula -- along with a bit of Algebra, you get the following suite of formulas, that can be used to figure out just about everything you need for DC electronics:E = IRP = IEP = I2RP = E2/RSo, for instance, if you want to come up with how much power a resistor is going to dissipate, for a particular voltage across that resistor: P = E2/R ... so, if your LED strip has, for instance, 150Ω resistors, and there are 3 LEDs in series with one of those 150Ω resistors, and each LED is running at, say, 3.2V, then P = (12V - 3 * 3.2V)2/150Ω = 38mW -- [Thus: 38mW is dissipated by each 150Ω resistor]If you want to know why that potentiometer is burning up: assuming your strip has 20 sets of 3 LEDs, and, again, the LEDs are running at 3.2V, then each 3 LED set is drawing the following amount of current: I = (12 - 3 * 3.2V)/150Ω = 16mAand, the total power, for the strip, is:P = 10 * IE = 10 * 16mA * 12V = 1.9WSo, if you put that in series with a 1/4W potentiometer, worst case, you're probably going to dissipate around a watt in that poor thing, and thus all the smoke and fire!Now, some "LED"s used in LED strips, are actually little mini-COBs ["COB" = "Chip On Board"], made up of THREE LEDs! So, our above calculation would, then, become:I = 3 * (12 - 3 * 3.2V)/150Ω = 48mAP = 10 * IE = 10 * 48mA * 12V = 5.8W!!!So, unless you're using one of those big-ol high wattage potentiometers, it probably doesn't have a chance in hell!!BTW: Your heating problem could also have to do with putting the LED strip in a closed box. You might need to provide some sort of ventilation -- especially if you are using a strip with those 3-LED COBs.
Details matter! What LED strips? What is their voltage and power rating? What 15A MOSFETs? What circuit did you use to connect to the Arduino? Have you measured the voltage output of your "camper power center" so you know that it is 12V?When you "connected your little multimeter" are you sure it was on the current measuring range? What EXACTLY did the display say?Steve
【Safe to Use】: The working voltage is 12V, extremely low heat, which is safe to touch. But please do not use power adapter that is higher than 12V to supply. No worry. Just enjoy. The wattage is 40W, Please be kindly informed that the total wattage of LED strip lights should not exceed the max wattage of power adaptor.
I connected my little multimeter between the LED strip and the power source and it closed the circuit to turn the lights on, but gave me an open-loop message on the readout...
extremely low heat, which is safe to touch
I have a bunch of your standard 2-pin led lighting strips that I have connected to my camper's 12v power source (shore power converted to DC via camper's power center).
converted to DC via camper's power center
The LEDs are spec'd for 12 volts, but I assume that these products are able to handle some variability of voltage input. I'm just not sure what decimal place that range occurs in. Is 1 volt extra too many, or is .1 volts too many?
Strips like this have three LEDs and one current limiting resistor in series.Three white LEDs in series normally drop about 10volt, leaving 2volt across the current limiting resistor.
In my first application I pulled out all the hardware for my fluorescent bulbs and put in LED strip inside the lighting cover