Understanding Voltage, Current, and Resistance Through TinkerCAD Circuits

Electricity is something that we use every day. But how much do you know about the electricity that powers our homes, schools, and offices? If you feel clueless about electrical engineering, don’t worry—you’re not alone. There are many people who haven’t had any exposure to electrical engineering principles, but learning about this topic can be super interesting and also quite helpful in your everyday life. Learning these concepts with hands-on activities is an excellent way to make sure that they stay with you for a long time. This instructable will explore three key electrical engineering principles: voltage, current, and resistance. Let’s get started.

-TinkerCAD account

Let's dive into TinkerCAD and understand Voltage, current, and Resistance

1. Sign in to your TinkerCAD account.

2. Create a new project in Circuits by clicking on the "Create New Project" button.

Activity 1: Create circuits with LEDs and batteries

In this first activity, we will use batteries of different voltages to see the effect that voltage has on a circuit. We will use TinkerCAD, a free online circuit simulator, to build our circuits.

what are Light emitting diodes?

A light-emitting diode (LED) is a two-lead semiconductor light source. In simpler terms, the longer lead is the positive terminal which needs to be connected to the positive terminal of the battery and the smaller lead of the LED is the negative terminal. The negative terminal of the battery needs to be connected with the negative terminal of the battery (black terminal).

After this, let’s start with a simple circuit consisting of just a LED (Light emitting diode) and a battery. after creating the circuit we need to start the simulation to see what is happening in the three circuits.

Case I (a) LED will burst

Reason: LEDs require 2 V whereas the source (battery) voltage is 9 V which is much more than the LED can tolerate.

Case II (a) LED in the danger zone

Reason: LEDs require 2 V whereas the source (battery) voltage is 3 V which is slightly more than the required one. Therefore the LED is in the danger zone.

Case III (a) LED will burst

LEDs require 2 V whereas the source (battery) voltage is 3 V which is slightly more than the required one. LED should be in the danger zone however it will burst.

Reason: There is one more important parameter i.e. current

What is current?

Current is the rate at which charge flows through a conductor. The SI unit for current is the ampere (A), and it can be either positive or negative.

Now the current passing through the circuit is 136 mA while the maximum current for safe LED operation is 136 mA. This is why the LED will burst.

 The next step is to protect the circuits. In order to protect the circuit, we will add a new component Resistance. Resistance is a component that will restrict the amount of voltage and current and thus pass the required voltage and current to the LED.

Activity 2 Protect the circuits by adding Resistance

What is Resistance

Resistance is a material that opposes the flow of current. The SI unit for resistance is the ohm (Ω),

How much Resistance is required :

The Resistance in all three circuits can be calculated using Ohm's law. The SI unit of Resistance is Ohms.

According to Ohm's law, the current through a conductor between two points is directly proportional to the voltage across the two points. The formula for Ohm’s law is:

I= V/R

Where,

I is the current in amperes,

V is the voltage in volts, and

R is the resistance in ohms.

Now, we will calculate the required resistance for all three circuits.

For circuit I

V= I*R : where LED forward Voltage =2V and current rating of LED 20 mA

V=Vs-Vf = Source Voltage - Forward Voltage of LED= 9-2 = 7V

7 = I*R

Putting the value of LED current

7=(20/1000)*R

Solving it we get

R= 350 Ohm

Similarly solving for Case II and Case III we get Resistance 50 ohm

Now, let’s see how current affects our circuit by adding a resistor in series with the LED.

As you can see, adding a resistor in series with the LED reduces the current flowing through the circuit. This is because the resistor opposes the flow of current. The larger the resistance, the smaller the current.

 After adding the required resistance, you will see that all three LEDs are glowing with equal brightness. 

This concludes our simple activity to understand Voltage, current, and resistance. We saw how these three critical parameters are interrelated and affect a circuit's functioning. We also learned how to protect a circuit by adding a resistor.

Voltage, current, and resistance are important concepts in electronics that are often confusing for beginners. This activity should help you understand these concepts better.

At skoolofcode we follow a hands-on learning approach, which means that you learn best by doing. So go ahead and experiment with different values of voltage, current, and resistance to see how they affect a circuit. Try building different circuits and see what you can create!