Don't worry, it won't last long, and we will try to make it fun.

The blue head-shaped thingy you've gotten in your kit is called a circuit board.

Professionals call this a printed circuit board or PCB. 

A PCB is a laminated sandwich structure of conductive and insulating layers.

Your circuit board has two functions:

They allow electrical charges to flow between components. This way, electronic components are powered, and they can do clever stuff using electricity. 

Circuit boards are usually made out of fiberglass-reinforced epoxy-laminated sheets.

These are also referred to as “FR4” sheets.

The FR4 sheets are used as the insulating non-conductive material, and copper is used as a conductive material.

FR4 and copper are both sandwiched together in thin sheets, and that’s how you get a circuit board. 

They’re used everywhere! 

In your phone, in your laptop, in your refrigerator, air conditioner. Basically, every electronic device you use has a unique printed circuit board that makes it work. 

Space travel wouldn’t be possible without them. 

He invented it in the 1930s, but the predecessors of modern-day PCBs have been around since the age of gramophones and vacuum tube radios, just in a somewhat different form.

Resistors are the most basic electronic components found in almost every electronic device.

They fall in the category of passive electronic components.

Passive electronic components do not generate electrical power and do not need electrical power to work.

They just modify the flow of electrical energy in their own unique way. 

Resistors that you have gotten in your package have a cylindrical shape and two tiny metal legs.

We call these legs “component leads”.

Resistors have a property of resistance - they lower the amount of electrical energy flowing through the circuit. They “resist” the flow of electrical energy.

The unit of resistance is called ohm and it was named after German physicist Georg Simon Ohm.

Resistors are used for tasks such as adjusting the flow of electricity through an electronic circuit.

The exact value of a resistor is measured with a device called an ohmmeter.

If we make an analogy to water flowing through pipes, the resistor is a thin pipe that reduces the water flow.

This is an electronic symbol for a resistor:

This is Georg Simon Ohm:

Every battery stores chemicals. These chemicals cause chemical reactions and generate electrical energy.

This battery is made out of a material called lithium.

Do you see the tiny “3V” written on the battery?

This is read as “three volts”.

You will see the number of volts written on almost every battery as it’s one of the most important pieces of information about the battery. 

Voltage is a type of “pressure” that drives charge through an electrical circuit.

For example, a mobile phone has a battery of 3.7 volts, and a car has a battery with a voltage of 12 volts. 

This particular battery size and model is called a CR2032 coin cell battery.

The battery holder is not as complex as the rest of the components, but it deserves a word or two. 

It's made out of plastics and has two pins that you'll have to solder in order to keep it on Marv's body. 

The battery holder will be used for holding the battery and giving life to your wacky robot.  

The switch you got in your kit is a power switch, and it helps you turn Marv on and off. You can easily do so with one simple push.  

The power switch controls the flow of power to an electric device - in other words, it connects and disconnects an electrical circuit.  

Switches are used in almost every electronic device. They are found in your mobile phone, computer, air conditioner, etc.

An electrical switch was invented in 1884 by John Henry Holmes, who used it for turning lights on and off.

A pushbutton switch is a small, sealed mechanism that completes an electric circuit when you press on it.

When you release your finger from the pushbutton, the spring retracts, the electrical contact is interrupted, and electrical energy won't flow through the
switch.

Switches have an on and off state that can be switched between by pushing the switch with your finger.

A pushbutton also has two states - on and off. A pushbutton will change its state if you push it with your finger, but it will automatically retract back to its original state when you remove your finger. 

These electronic components will make your MARV’s eyes light up. 

LEDs convert electrical energy into visible light.

This is an electronic symbol for a light-emitting diode:

Light-emitting diodes (LEDs) are polarized. 

Because of this, you need to pay attention to how you are going to place your LED in the electronic circuit.

The tiny metal legs of every LED are not the same length.
They mark polarity! 

The positive leg is longer (we call this one the anode), and the shorter one is negative (this one has a funny name - cathode).

If you put the LED in the wrong way, it won't light up because the electrical energy will not be able to flow through it.

LEDs can be damaged if they receive too much energy. 

Oh no! The coin cell battery supplied with your MARV is too much for the poor
little LEDs”.

But don't worry, we sent resistors to the rescue! 

Resistors will limit the amount of electrical energy flowing through the circuit and save your LEDs from getting damaged.

A Russian inventor Oleg Vladimirovich Losev made the first LED in 1927.

LED lightbulbs are the most efficient type of lightbulbs.

Unlike “regular” “old”  bulbs (we call these incandescent lightbulbs), which release 90% of their energy as heat, LEDs use energy far more efficiently with very little wasted heat.