Hi, I have read about how to use a resistor in series with led. However, it is my understanding that the values plugged into ohms law (I and V) are values you want to flow with resistance that is result. I assume, if I want 2 amps to flow through and out of my resistor with an input of 10 volts, the equation gives that I should place a 5 ohm resistor. However, should the above be true I have come upon a problem.
An led has n given forward voltage (b, being the needed amperage). The voltage fed, should be atleast, n. I assume. However, all tutorials show that to get this, I must subtract the supply voltage, by the required forward voltage, and then divide by the amperage (b). This would then give me the needed resistor to place between my supply and my led. My confusion is that, this would give me a resistance to make sure the voltage after the resistor is supply minus n, and the current to be b. But! n does not equal the difference of supply and n voltage. I do not understand why this is used. Unless my understanding of the resistor and it's values are incorrect and voltage, current values of the resistor are what is to be dissipated (or taken from the supply) but if that's the case, we are only taking b current from the supply, and we need that as the minimum current. I hope someone can sort and teach me a solution for my confusion. Thank you.
An led has n given forward voltage (b, being the needed amperage). The voltage fed, should be atleast, n. I assume. However, all tutorials show that to get this, I must subtract the supply voltage, by the required forward voltage, and then divide by the amperage (b). This would then give me the needed resistor to place between my supply and my led. My confusion is that, this would give me a resistance to make sure the voltage after the resistor is supply minus n, and the current to be b. But! n does not equal the difference of supply and n voltage. I do not understand why this is used. Unless my understanding of the resistor and it's values are incorrect and voltage, current values of the resistor are what is to be dissipated (or taken from the supply) but if that's the case, we are only taking b current from the supply, and we need that as the minimum current. I hope someone can sort and teach me a solution for my confusion. Thank you.