Basics of Electronics Session #3 PDF

Basics of Electronics Session #3 Basic Electrical Components & Devices  Electricity & Magnetism 01 What is a magnet? What happens when electricity flow in a conductor? Motors 02 What is a motor?...

Basics of Electronics Session #3 Basic Electrical Components & Devices  Electricity & Magnetism 01 What is a magnet? What happens when electricity flow in a conductor? Motors 02 What is a motor? How does a generator Motor? Generators 03 What is an AC generator? How does a generator work? Transformers Topics 04 What is a transformer? How does a transformer work?  Inductors 05 What’s an inductor? How does it operate in circuits? Relays 06 What’s a Relay? How can we use it? Capacitors 07 What’s a capacitor? How does it operate in a circuit? Topics  E&M What is a Magnet? 0 The basic definition is that a magneto is a rock or a piece of metal that can 1 pull certain types of metal toward itself. The force of magnets, called magnetism, is a basic force of nature, like electricity and gravity.  E&M What is a Magnet? 01 Magnetic Poles The magnetic force in a magnet flows from the North pole to the South pole. Like electrons have charges, Magnets have poles. North & South attract but N-N & S-S repel. Just like Earth! Magnets Types 02 The three types of magnets are temporary, permanent, and electromagnets. Magnetic Field 03 A magnetic field is the area around a magnet that has magnetic force.  E&M What is a Magnet? 0 Magnetic field is determined by lines that correspond to which direction the 1 magnetic force is flowing. See this video 🡪 Magnetic Field Lines with a bar magnet and an electro-magnet  E&M Electro-Magnetism 0 When an electric current flows through a conductor, it generates a magnetic 1 field around the conductor. The magnetic field can be increased by coiling the wire. How to make a homemade electro-magnet 🡪 Electromagnet Demo  E&M Electro-Magnetism 01 Electro-magnet direction The direction of the magnetic field is determined by Right Hand Thumb Rule. Electro-magnet intensity 02 We can increase magnetic field by increasing the current flowing in the conductor. Solenoid 03 A magnetic field is also increased by creating a Solenoid around an iron core. By increasing the number of turns of the solenoid, the magnetic field increases.  Motors Applications of Electro-magnetism 0 Electromagnetism serves as a basic principle of working for many of devices 1 that we use. We will focus on how electro-magnets operate with different configurations. One of the most famous applications is a Motor.  Motors What is a motor? 0 Motors are generally machines that convert electrical energy into mechanical 1 energy. When an Electro-magnet is put in External magnetic field, a force is applied to that electro-magnet causing it to move.  Motors What is a motor? 0 See this video to understand more how motors work 🡪 Working Principle of DC 1 Motor (animation of elementary model) - YouTube  Motors What is a motor? 0 Motors don’t have just one coil inside of them, They have multiple coils to have 1 better performance. What we saw until now is DC motor which you apply DC electricity to it. There’s also AC motors which we will discuss later.  Motors What makes Motors different from one to another? 01 Voltage Type & Rating The first thing to consider when choosing a motor is the voltage. If this is a DC motor, we’ll need a DC voltage source (Like a battery or a Power Supply). Also, we need to know what is the rated voltage for this motor. Is it 12VDC? Is it 5VDC?. If we apply different voltage than the rated voltage, the motor might draw higher current from your circuit and could damage the power source and will make the motor overheat or even burn out!. Also, generally, it will shorten its 5VDC MOTOR life span and affect its performance. Remember that at rated voltage the motor works best!.  Motors What makes Motors different from one to another? 02 Current rating Not all motors draw the same amount of current. It’s necessary to know how much current your motor would need from your source. If you have a source (A power supply) that can provide 10A and the motor needs 15A then the power supply would be damaged. The power source must provide higher current than the motor rated current. Check this link to know the specs of this motor: 5V DC motor - HUB360 In general, You can motor voltage and current from its datasheet or its name plate.  Motors Where can you find motors? 0 If a device is moving using electricity, then it’s a motor. From vehicles to home 1 blenders. After all, a motor is a machine that moves when applying electricity to it! Activity #1 A Motor as a Thruster! A Thruster is a motor with a propeller that is used to push space & water crafts. Basically, what you will do is that you will turn on a 12VDC motor that is used as a thruster (With the help of your instructor of course). Is there a difference when changing the polarity of this motor??  Generators Remember generators? 0 We spoke before about generators and what they’re used for. But actually we 1 can consider a generator as the exact opposite of a MOTOR! We’re talking here about a Dynamo.  Generators What are Generators 0 A Dynamo is a machine for converting mechanical energy into electrical energy, 1 typically by means of rotating coils of copper wire in a magnetic field. Sounds familiar? Yes, it does the opposite function of a Motor.  Generators What are Generators 0 A generator works on a basic phenomena called: Electromagnetic Induction 1 Faraday’s First Law of Electromagnetic Induction states that whenever a conductor is placed in a varying (moving) magnetic field, voltage is generated across its terminals.  Generators What are Generators 0 See these videos to understand more how generators work 🡪 AC Generator | 1 ElectroMagnetic Induction | Electric generator | Working of AC Generator I Physics – YouTube Simple explanation of a generator – YouTube The World's Simplest Generator - YouTube What we covered so far is the AC generator, if we want a DC source we can convert this AC electricity using some devices like power supplies which we will cover later.  Transformers How does AC electricity travels to our home? 0 We said before that we get electricity from the High Dam in Aswan. This electricity 1 is at very high voltage (around 500 KV AC) and we use in our home 220V AC!! Then how do we get this? We use a Transformer!  Transformers What are Transformers? 0 A Transformer is an electrical device that uses the principle of electromagnetic 1 induction to transfer energy from one electric circuit to another. Not only transferring but also increasing or decreasing its voltage & Current depending on what we need!.  Transformers What are Transformers? 0 The transformer is usually built with two coils around the same core. The primary 1 coil or input coil is connected to supply side while secondary coil supplies power to load. The second one is called the output coil. Energy is transferred from the primary to the secondary by electromagnetism.  Transformers We have 2 types of transformers: A transformer designed to A transformer designed to reduce increase the voltage from primary the voltage from primary to to secondary. secondary. Step-up Transformer Step-down Transformer  Transformers How to control the output voltage? 0 By controlling the number of turns, we can control how much voltage is on the 1 secondary. According to the formula below, If we increase the number of turns on the primary side, then voltage will be lower on the secondary side and this will make the transformer a Step-Down transformer! Where N is the number of turns of the coil  Transformers What are Transformers 0 See these videos to understand more how transformers work 🡪 1 Transformers - Electric Power transmission - YouTube Let’s talk about something else: Before, we have discussed resistance as one of the basic components in any electrical circuit. There’s also some other components that you might find in any circuit. The first one is called an INDUCTOR. This is not totally different from what Inductors we discussed in this session as the inductor is just a coil! What is an inductor? An inductor is a component that is used in most power electronic circuits to store energy in the form of magnetic field when electricity is applied to. One of the key properties of an inductor is that it impedes or opposes any Inductors change in the amount of current flowing through it. This means that when you try to change the state of the circuit, the inductor delays the change! See the difference between the 2 circuits below? What is an inductor? They’re connected in series with a load. If you connected in Parallel, it would be short circuit! If you connected like the below circuit and turned the SW ON, the current will Inductors gradually charge the coil until it reaches the maximum amount. This connection would create a path for electrons that is free of resistance because it’s parallel with the lamp and will create a short circuit! But after a small period of time. What is an inductor? Inductors come in different sizes and shapes. Like resistance is measured in Ohms, inductors has a property called inductance (L) and it’s measured in a unit called Henry (H). Inductors The inductance of a coil refers to the electrical property of an inductive coil to oppose any change in the current flowing through it. The higher the inductance the higher the ability of an inductor to store energy. What is an inductor? Watch this video to learn more about inductors 🡪 Inductors and Inductance - YouTube Inductors Why do we need it? Most of inductors’ applications are in AC circuits because inductors oppose the change of current which happens in AC circuits, in DC the current is only building at the beginning (very small time) and then stays constant. we Inductors will not dive into AC circuits for now. However, You might have notice that an inductor is nothing but a wire wrapped around (coiled) which is the basic component of transformers!. Also, inductors are used as inductive proximity sensors! Which is used for positioning and detection of metal objects. What are Relays? One of the major components in a circuit and an application of inductors is a Relay. A relay is an electrically operated switch. They use an electromagnet to mechanically operate a switch. Relays The idea is that when applying voltage to the coil, it acts as an electro-magnet and pulls a metal strip inside. The metal strip switches the connection from Common terminal & Normally-Open to Common & Normally-Closed. So, in General, a Relay is like a switch but instead turning it on & off but our hands, we use electricity to do the work! What are Relays used for? Relays can be used in for AC and DC applications. They have high current capabilities, which means they’re good to drive high current drawing applications like motors. Relays They’re also used to switch from one circuit to another like the circuit below, a Relay is used to drive 120VAC lamp with a push button. This small push button cannot work in high AC voltage like 120VAC, so a small battery is used just to apply voltage to the coil and then the relay connects the lamps to the 120VAC. What are Relays used for? When using a Relay, you need to check what is the voltage needed to be applied to the coil's terminals. Some Relays are 5VDC and some are 12VDC, and some are not even DC! Relays What we typically use is 5VDC and 12VDC. What is a Relay? Watch this video to learn more about Relays 🡪 Relay - Explained and animated - how relay works - YouTube Relays Activity #2 A simple Relay circuit! Connect the following circuit This circuit switches the LED ON/OFF using a Relay. The idea is that we drive the LED using a different power source! Activity #3 Switching between two LEDs! Connect the following circuit This circuit switches between the RED LED & the GREEN LED. When the push button is OFF, the RED LED is ON and the GRN LED is OFF. When the push button is ON, the RED LED is OFF and the GRN LED is ON. What is a Capacitor? Another component is a Capacitor, it’s an electronic device that stores electric energy. It is similar to a battery, but can be smaller, lightweight and a capacitor charges or discharges much quicker. Capacitors Like an inductor, One of the key properties of a capacitor is that it impedes or opposes any change in the amount of voltage across it. It’s a component used to store energy in the form of an electric field. Capacitor operation in a circuit: The capacitance is measured in Farads, and as the capacitance increases , it takes a longer time to discharge the stored energy. Capacitors The Capacitor consists of 2 conducting plates, having a dielectric material in between. When the switch closes, the capacitor becomes charged, with negative charges being attached to the lower plate, while the upper plate is positively charged. When the capacitor is fully charged , it becomes saturated and acts as an open-circuit, as no charges are allowed to pass through it. If the switch opens, the lamp connected in parallel doesn’t turn-off immediately; because the capacitor discharges the stored energy into the lamp. Capacitor operation in a circuit: Capacitors are Connected parallel to the load in DC circuits. Connecting it in series would work as an open circuit! Consider a Capacitor as a battery, but its charge and discharge time is Capacitors much faster than a battery. Some capacitors have polarization (+ve and -ve) and some are not so please check which type is with you to connect it properly. Capacitors applications: Capacitors have a variety of applications, like an inductor most of them are in AC circuits because also capacitors oppose the change in AC is changing (Alternating). Capacitors In DC circuits, Capacitors are used in parallel to components which are subjected to noise or sudden voltage drops. Let’s say you have a motor in a circuit and a camera, when starting, the motor tends to draw high current. This will lead the voltage to drop in a circuit. Cameras need to have a certain voltage across its electronics, so we put a capacitor in parallel to store some voltage and try to moderate the voltage drop until the circuit is stable. It’s exactly like the circuit in the last slide. What is an capacitors? Watch this video to learn more about capacitors 🡪 Capacitors and Capacitance: Capacitor physics and circuit operation – YouTube Capacitors Activity #4 Capacitor effect on a circuit! Connect the following circuit The capacitor is used to fade the LED when the Switch is opened. A 1000uF is used (1mF) you can use higher capacitor to see the effect of capacitance on discharge and discharge time. Press the push button for 1 Second observe, and then try for 5 seconds and 10 seconds. Do you see any difference on discharge time? The arrow pointed to at the bottom of the circuit is just the GND (don’t get confused!) THANK YOU