Arduino Forum

Products => The Arduino Starter Kit and Basic Kit => Topic started by: montana63 on Sep 26, 2018, 06:26 pm

Title: inconsistencies between project 1 and 2,3
Post by: montana63 on Sep 26, 2018, 06:26 pm
Hi,

I'm trying to not skip anything and going deep into details of each projects and there's something I can't get my head around.

On project 1 the resistance is connected to the anode leg of the LED whereas it's connected on the cathode for projects 2 and 3.

In my mind it all made sense to have the resistance on the anode so it's limiting before hitting the LED so it doesn't blow up because of too much current however seeing the resistance connected to the cathode doesn't really make sense to me as it looks like full current is going through the LED and then it's being limited by the resistance.

I'm sure I'm wrong but I just can't understand why.

Thanks for your feedback
Title: Re: inconsistencies between project 1 and 2,3
Post by: pert on Sep 26, 2018, 07:41 pm
It doesn't matter which side you put the resister on. It's a circuit.
Title: Re: inconsistencies between project 1 and 2,3
Post by: montana63 on Sep 27, 2018, 09:47 am
thanks Pert, "it's a circuit" it actually doesn't make sense to me.

I understand the classic convention is having everything going from + to - I guess this is where I'm getting confused.
Title: Re: inconsistencies between project 1 and 2,3
Post by: pert on Sep 27, 2018, 10:17 am
The resistor is there to limit the amount of current that can flow through the circuit.

Think of a valve on a water hose. No matter where on the hose that valve is, it still limits the water flow.

It's just like if you had a switch on the LED circuit. Whether the switch is on the anode side of the LED or the cathode side, the light will still turn off when you open the switch because then the charge can't move through the circuit.