Simulating Circuits using softwares: Introduction to Tinkercad-

Tinkercad is a free, online platform that provides tools for 3D design, electronics, and coding. It is widely used by beginners, hobbyists, students, and educators to create simple 3D models, simulate electronic circuits, and explore basic programming concepts. We'll be using Tinkercad to simulate basic circuits using components like resistors, LEDs, batteries, Multimeter etc and also to learn the basics of Arduino later in the course.
Some of the main features of Tinkercad are :

Features of Tinkercad Circuit Simulation

• Virtual Components: Includes resistors, LEDs, capacitors, transistors, breadboards, and microcontrollers (e.g., Arduino).
• Real-Time Simulation: Test circuits without the need for physical components.
• Pre-Configured Examples: Learn about electronics through ready-made circuit examples.

You can access Tinkercad by this link.

Once you register, you'll be redirected to the dashboard , which will look like this:

On this page, click on CREATE and then click on Circuits
You will see an interface like this:

Here you can drag and drop components from the Components menu on the right.

Now let's create a basic circuit with a LED and resistor:

Connect a LED, 9v battery and a resistor in sreies as shown below (press R to change the orientation of components) :

As a general convention, always use Red wires for +ve power connections,and black wires for -ve power connections. That makes it easier to debug when you work on a bigger, more complex circuit.

Now our basic circuit is ready! Click on start simulation and you'll notice that the LED glows up.

Change the resistance of the Resistor by clicking on it and notice the change in brightness of the LED. You'll notice that once the resistance drops very low, less than 344 ohms, The LED will have a high current indicator:

So we have to make sure that the current passing through the LED doesn't exceed 20mA.
We can find the current passing through the LED by Ohm's law . For example for a 1 kilo-ohm resistor, we have -

Ohm's Law:

I = V / R

Substituting the values:

I = 9 / 1000

Result:

I = 0.009 A or 9 mA

But if we want to monitor the current value continously for different values of reistance, it is more convenient to use a multimeter.
Connect a multimeter in the circuit as shown below and click on Start Simulation.

Now we can easily observe the values of current for varying parameters.
The important thing to notice here is that the value of current in the multimeter is not accurate according to the Ohm's law. According to Ohm's law, the amomunt of current passing through the LED should be 9mA (as calculated above). But the multimeter reading shows 7.04 mA.

This is due to the internal resistance of the LED. As the LED is connected in series with the circuit, the internal resistance of the LED will also cause effect on the current passing through it.

I hope you're now familiar with the basics of TinkerCad. You can try out various circuits by including multiple LEDs, potentiometers etc. In the upcoming modules we'll discuss a variety of circuits and simulate them on TinkerCad!