Basics of Electronics
Every electrical and electronic component/device/gadget basically works on the flow of electrons. Although there is no desperate need to get into the depth of these concepts, we believe that you should know the basics before you get started. The art of making (DIY) is that you won’t usually need to know everything from the start, but will learn everything on the way while making. In short its learning by doing.
Electronics is based on two basic type of components which are usually referred as core of everything that we see in electronics.
- Passive Circuit Elements
- Active Circuit Elements
Passive Circuit Elements
Passive circuit elements are those which do not generate electricity they either absorb electricity and convert it into heat or store it in an electric field or a magnetic field. They do not need to be powered separately they only work when there is a flow of current through them.
Resistor is one of the basic example of passive circuit element which limits the flow of electric current through it. Unit used to measure resistance is ohms.
Use cases: Why do we use resistors? We basically use them as a protection element in our circuit so to avoid breaking of a comparatively expensive circuit element.
We use them beside different circuit elements to limit the flow of current according to need. In basic examples we will use it along with LEDs to avoid burning them. Some components usually have internal resistors and protection circuits in that case we might not external ones.
How do we know we need 220 ohm resistor beside this led? We can use the following formula for this.
Here ‘V’ is voltage applied to the circuit and ‘I’ is the current needed for that component to run. Whatever value we get in output will be the resistance in ohm.
How to read resistors:
Color codes are key….. literally.
A device we use to store electric charge. It acts like a temporary battery in the circuit.
Unit used to measure capacitance is Farad.
Use cases: Why do we use capacitors? When power supply cuts off, sudden change in current and voltage usually affect the appliances badly. To avoid this, we add capacitors in circuits, so even if power goes off there is linear decrease in current and voltage so to avoid blowing-up of the components.
We also use them to smoothen the sudden change in current and voltage in circuits due to constant turning on and off of different appliances.
It is a device that stores energy in the form of a magnetic field. It is used to block the flow of AC current in circuit.
We don’t need to go into the details of inductors right now; we will learn more about it in a more advanced tutorial.
Active Circuit Elements
Active circuit elements are those that can generate energy and they typically need an auxiliary circuit and power to work. In simple words we can count diode, transistor, IC’s and power supply as active circuit elements. These are usually semi-conductor devices
Power Supply: We use power supply to power our circuits and components. There can be voltage sources or current sources depending on what element we want to vary.
A semiconductor device with two terminals, typically allowing the flow of current in one direction only. As it’s an active device it requires a certain voltage to operate which is usually 0.7 volts or varies according to the material used.
A transistor is a semiconductor device used to amplify current or as a digital switch. It possesses at least three terminals. It is an important component in the world of electronics.
Transistor as switch
Transistor as an amplifier.