Voltage Drop On The LED - LEDs And Multiplexing - Arduino Forum Home » Arduino Led Voltage Drop » Voltage Drop On The LED - LEDs And Multiplexing - Arduino Forum Maybe your like Arduino Led Voltage Meter Arduino Lesson 4 Rgb Led Code Arduino Liquidcrystal.h Commands Arduino Liquidcrystal.h No Such File Or Directory Arduino Liquidcrystal_i2c Download Voltage drop on the LED Other Hardware LEDs and Multiplexing leonhard_euler June 25, 2019, 9:38pm 1 Hello, Im new to this forum and quite new to electronics. Hope Im writing this post in correct section. I know some basics like Ohms law etc. Im going through the 15 projects from arduino UNO book. Before I plug things into Arduino Im testing my circuits with TinkerCad. Lets say I have a serial circuit powered by 5V pin (Arduino UNO). In the first project the 220 ohms resistor is chosen (would like to see calculation of why is it 220). Ohms law says that current in the circuit will equal to around 20mA. So far so good. According to the book thats around maximum that LED can handle. I understand that values are taken from some kind of LEDs datasheet (or whatever it is called :)). When I construct above circuit with TinkedCad I get a 2.08V voltage drop on the LED. What I dont understand is how TinkedCad knows exactly what is a voltage drop and why while increasing resistance a voltage drop on the LED decreases? Additionally current in above circuit with LED is 13.5mA according to TinckerCad... Does a LED decreases the current in the circuit somehow? Appreciate any attempt of explaining it to me Cheers vaj4088 June 26, 2019, 3:55am 2 I don't know anything about TinkerCad or why its calculations are right or wrong. The voltage drop of an LED depends upon the current through it, but does not vary too much near the current needed for continuous light. This voltage drop and current will be on the data sheet. The current through the resistor is given by Ohm' s law, where the voltage is your supply voltage (in this case 5.0 volts) minus the forward voltage drop of the LED, and obviously the resistance is the value of the resistor. This of course assumes that the resulting calculated current is "near" the current in the data sheet for the LED. In this case, if the data sheet uses 20 mA and your calculation results in 15 mA, that is near enough for many purposes. Grumpy_Mike June 26, 2019, 5:34am 3 What I dont understand is how TinkedCad knows exactly what is a voltage drop All simulators has mathematical models to predict the behavior of components under different conditions. Any model can not hope to simulate all sorts of LEDs so a "generic" LED model is used. This is not the same as a real life LED and so the changes you see in the forward voltage drop across an LED when it responds to current changes are only what the model will predict. In real life these will almost certainly be different. and why while increasing resistance a voltage drop on the LED decreases? Because that is how real LEDs behave. The forward voltage drop changes with current, but not in a linear way like it does in a resistor. Large changes in current will produce small changes in the LED's forward voltage drop. Does a LED decreases the current in the circuit somehow? Yes. By the fact that it has a forward voltage drop that is dependent on current means that as that drop changes so does the current for any given value of fixed resistor. Related topics Topic Replies Views Activity Why is there a voltage drop when I add a resistor? General Electronics 9 2778 February 23, 2023 Random LED question General Electronics 29 1902 May 6, 2021 Measured actual voltage and it dropped? LEDs and Multiplexing 11 1642 May 6, 2021 Basic resistance question General Electronics 10 2715 May 6, 2021 Current flow & Voltage Drops in series & parallel LEDs and Multiplexing 19 7734 May 6, 2021 Tag » Arduino Led Voltage Drop Understanding Voltage Drop And LEDs - Arduino Forum LEDs In Series, Resistor And Voltage Drops - Arduino Forum Finding A Forward Voltage Drop Across An LED - Arduino Forum Forward Voltage Vs. Voltage Drop - General Electronics RGB LED Voltage Drop - LEDs And Multiplexing - Arduino Forum Voltage Drop Problem(trying To Power On A WS2812 Led Strip) Why Do My LED's Dim And Voltage Drop When Flashing At High Speed? Voltage Drop Of Arduino's Power Regulator - General Electronics How Many Volts Can A Typical LED Take? - Frequently-Asked Questions Calculate LED Voltage Drop - General Electronics - Arduino Forum How To Add Led Indicator And Avoid Voltage Drop - Arduino Forum Measuring The Forward Voltage Drop Of LED - Arduino Forum LED Current Draw - General Electronics - Arduino Forum Current Flow & Voltage Drops In Series & Parallel - Arduino Forum
