03: Schematics, Ohm's Law and Potentiometers

 A schematic symbol is a simplified drawing of the part as shown in the example here. A wiring diagram is known as a schematic. Schematics are the standard method for people to trade information about circuits. Being able to read and write schematics is a key skill.
 

 The following 3 different resistors are used for the basic LED setup, which consists of one LED and one resistor connected from 5V to ground. 

1. Brown Black Brown: 100Ω
2. Brown Black Red: 1 KΩ
3. Brown Black Orange: 10 KΩ

The results shown that the larger the resistor, the dimmer the LED is.  A smaller resistor offers less resistance and therefore emits a brighter LED.


You adjust the brightness of the LED by changing 
the resistance on the POT

Forward Voltage and KVL
For every LED, in order to use it properly, we need to know the Forward Voltage, it is the 'negative voltage', used by the LED when it's on.

For 99 percent of LEDs, you will encounter, the optimal current is 20 milliAmperes (0.02 A).
If you want a brighter LED, you can push it up to 30mA.

Since we want to maximize the brightness of our LED using the 5V power supply (the one I made measured 5.13V), we need to calculate the value of the resistance.

R = V/I
R = 3.8 /.02 = 164 Ω, where 3.28 is obtained by subtracting 1.85 from 5.13V

The closest resistor I find to use it in my circuit is 220 Ω because the next resistor has to be larger than 164 Ω.
  

The Fear Artist