# love o meter - why use resistors

im new to the whole thing and couldnt find an explenation on what purpose do the resistors in the project serve. why not use regular wiring instead.

the love o meter is the 3rd project in the starter kit book

Has it occurred to you that not everyone on the planet knows what a "love o meter" is?

aarg - it's one of the projects in the official Arduino starter kit.

abfist - there is a section of the forum devoted to the starter kit further down the board. If you ask in there people are more likely to know what you are on about.

The resistors are used to limit current through the LEDs. Witout the resistor, when the LED is turned on, it looks like a dead short and either the output pin driving the LED will fail or the LED will fail. Google Arduino LED current limit.

aarg: Has it occurred to you that not everyone on the planet knows what a "love o meter" is?

Indeed - I opened this topic hoping to find out what it is! Apparently out of luck here :-(

groundFungus: The resistors are used to limit current through the LEDs. Witout the resistor, when the LED is turned on, it looks like a dead short and either the output pin driving the LED will fail or the LED will fail. Google Arduino LED current limit.

shouldnt the resistor be infront of the led to limit the power coming in? as the cirtuit is drawn you have the led and then the resistor.

As long as the resistor is in series with the LED, it doesn't matter whether it's before the LED or after it.

abfist: shouldnt the resistor be infront of the led to limit the power coming in? as the cirtuit is drawn you have the led and then the resistor.

In a series circuit, the current through each of the components is the same, and the voltage across the circuit is the sum of the voltages across each component

abfist: shouldnt the resistor be infront of the led to limit the power coming in? as the cirtuit is drawn you have the led and then the resistor.

You don't understand current flow - it happens everywhere round the circuit simultaneously (unless you are working at very very high frequencies).

The current has to pass though all the components whatever order they are in, and feels the resistance of all of them. The exact same current flows through the anode side of the LED as the cathode side...