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Chapter 01: Basic Principles of Electricity 1.1. Fundamentals of Electricity and Understand Electrical Quantities 1.1.1. Define the electric charge (Q), Current (I), AC and DC Current, Source, Load, Path, Electricity, Voltag...

Chapter 01: Basic Principles of Electricity 1.1. Fundamentals of Electricity and Understand Electrical Quantities 1.1.1. Define the electric charge (Q), Current (I), AC and DC Current, Source, Load, Path, Electricity, Voltage. 1. Electric Charge (Q): Electric charge is the amount of electricity present in an object. It's what makes electricity flow and is measured in coulombs (C). 2. Current (I): Current is the flow of electric charge through a material, like a wire, measured in amperes (A). It’s how much electricity is flowing. 3. AC (Alternating Current): AC is a type of current that changes direction periodically. It’s used in power outlets at home. 4. DC (Direct Current): DC is a type of current that flows in one constant direction, like the electricity from a battery. 5. Source: The source is the origin of electricity, like a battery or a power station, that provides energy to the circuit. 6. Load: The load is the device that uses electricity in a circuit, like a light bulb or a motor. 7. Path: The path is the route electricity takes to flow, usually through wires, connecting the source and load. 8. Electricity: Electricity is the flow of charged particles (usually electrons) that powers devices and appliances. 9. Voltage: Voltage is the electrical force that pushes the current through a circuit, measured in volts (V). It’s like the pressure that drives the flow of electricity. 1.1.2. Why Does Current Flow? Current flows because of a difference in electrical potential (voltage) between two points. This difference creates a force that pushes electric charges (like electrons) through a conductive material, such as a wire. If there is a complete path (a circuit) and a power source (like a battery or power supply), the current will continue to flow from the higher potential (positive) to the lower potential (negative). 1.1.3. Characteristics of Ohm’s Law Ohm’s Law describes the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. The law states that:   The current (I) through a conductor is directly proportional to the voltage (V) across it.  The current is inversely proportional to the resistance (R) in the circuit.  The formula is V=I×RV = I ¥times RV=I×R, where if you increase the voltage, the current increases, and if you increase the resistance, the current decreases (assuming the other variables are constant). 1.1.4. Define Passive Devices, Active Devices Passive Devices Passive devices are components that do not need an external power source to operate. They cannot amplify signals or control current on their own; they simply store or dissipate energy. Examples include resistors, capacitors, and inductors. Active Devices Active devices require an external power source to operate and can control the flow of electricity. They can amplify signals and regulate current. Examples include transistors, diodes, and integrated circuits. 1.1.5. Define Power (Watts), Conservation of Power, Relation between Voltage, Power, and Current Power (Watts) Power is the rate at which electrical energy is used or produced. It’s measured in watts (W) and indicates how much work is being done by an electrical device. For example, a 60W light bulb uses 60 watts of power. Conservation of Power The conservation of power principle means that in a closed system, the total amount of power remains constant. Power can't be created or destroyed, only converted from one form to another, like electrical power being converted to heat or light. Relation between Voltage, Power, and Current Power (P) in an electrical circuit is the product of voltage (V) and current (I). This relationship is expressed by the formula: P=V×IP = V ¥times IP=V×I This means that power increases if either the voltage or current increases (as long as the other remains constant). 1.1.9. Power used by Resistors (P = I2 ∙ R) The formula P = I^2 * R explains how resistors use power: 1. Current Flow (I): When current flows through a resistor, electrical energy is converted into heat due to the resistor's opposition to the flow of electrons (resistance). 2. Resistance (R): The resistor limits the current in the circuit. The higher the resistance, the more energy is used to push the current through, resulting in more power being converted into heat. 3. Power Dissipation: The resistor dissipates this power in the form of heat. The amount of power depends on the square of the current (which means even a small increase in current leads to a large increase in power) and the resistor’s resistance. This heat is often the reason resistors get warm during operation. Thus, resistors "use" power by converting electrical energy into heat, based on the current flowing through them and their resistance.  Chapter 07: Understand Transistors. Operational Amplifiers and Special Devices 7.2Operational Amplifiers 7.2.1 Define Operational Amplifier (OP-Amp) An Operational Amplifier (Op-Amp) is an electronic device that can amplify (increase) weak electrical signals. It has two input terminals and one output terminal and is commonly used in signal processing, control systems, and analogue electronics. Working Principle of an Op-Amp: 1. Inputs: The Op-Amp has two inputs – one is the inverting input (−) and the other is the non-inverting input (+). 2. Amplification: The Op-Amp amplifies the difference between the voltages applied to these two inputs. 3. Output: The amplified signal is produced at the output terminal. If the non- inverting input (+) is higher than the inverting input (−), the output will be positive, and vice versa. 4. High Gain: Op-Amps have very high gain, meaning they can take very small input signals and make them much larger. 5. Feedback: The performance of an Op- Amp can be controlled using feedback, which helps stabilize the gain and make it more predictable. 6. Power Supply: An Op-Amp needs an external power supply (positive and negative voltages) to operate. In short, Op-Amps take a small difference between two input voltages and amplify it, which makes them useful for tasks like signal amplification, filtering, and mathematical operations in circuits.  7.2.2 Define the types of (OP-Amp) 7.2.2.1 The Non-inverting Voltage Amplifier A Non-inverting Voltage Amplifier is a type of operational amplifier (Op-Amp) circuit where the input signal is applied to the non-inverting input (+). The output signal is in phase with the input signal and is amplified. Working Principle: 1. Input Signal: The input voltage is applied to the non-inverting terminal (+) of the Op-Amp. 2. Amplification: The Op-Amp amplifies the input signal based on the feedback network. 3. Feedback Resistors: Feedback resistors are used to control the gain of the amplifier. The gain is determined by the ratio of the resistors (Rf and Ri). 4. Output Signal: The output voltage is a larger version of the input voltage and is in phase (the same direction) as the input signal. 5. Gain Formula: The voltage gain Av​ of the amplifier is given by Av=1+Rf/Ri, where Rf is the feedback resistor and Ri​ is the resistor connected to the ground. 7.2.2.2 Inverting Voltage Amplifier An Inverting Voltage Amplifier is a type of operational amplifier circuit where the input signal is applied to the inverting input (−). The output signal is inverted (180 degrees out of phase) and amplified. Working Principle: 1. Input Signal: The input voltage is applied to the inverting terminal (−) of the Op-Amp. 2. Amplification: The Op-Amp amplifies the input signal with the opposite phase. 3. Feedback Resistors: Feedback resistors are used to set the gain of the amplifier. The gain is determined by the ratio of the resistors (Rf and Ri). 4. Output Signal: The output voltage is the amplified version of the input  voltage but inverted (opposite phase). 5. Gain Formula: The voltage gain Av of the amplifier is given by Av=−Rf/Ri, where Rf is the feedback resistor and Ri is the resistor connected to the input signal. 7.2.3 Inverting Current-to-Voltage Transducer An Inverting Current-to-Voltage Transducer converts an input current into a proportional output voltage. The output voltage is inverted (opposite phase) and proportional to the input current. Working Principle: 1. Input Current: The input current is applied to the inverting terminal (−) of the Op- Amp. 2. Feedback Resistor: A feedback resistor (Rf) is used to convert the current into a voltage. 3. Output Voltage: The output voltage is the amplified and inverted version of the voltage across the feedback resistor, which is proportional to the input current. 4. Gain Formula: The output voltage Vout ​ is given by Vout=−Iin⋅ Rf ​ , where Iin is the input current and Rf​ is the feedback resistor. 7.2.4 Non-inverting Voltage-to-Current Transducer A Non-inverting Voltage-to-Current Transducer converts an input voltage into a proportional output current. The output current is in phase with the input voltage. Working Principle: 1. Input Voltage: The input voltage is applied to the non-inverting terminal (+) of the Op-Amp. 2. Feedback Resistor: A feedback resistor (Rf) is used to convert the voltage into a current. 3. Output Current: The output current is proportional to the input voltage and is in phase with it. 4. Gain Formula: The output current Iout is given by Iout=Vin/Rf ​ ​ , where Vin​ is the input voltage and Rf is the feedback resistor. 7.2.5 Inverting Current Amplifier An Inverting Current Amplifier increases the magnitude of an input current while inverting its phase. Working Principle:  1. Input Current: The input current is applied to the inverting terminal (−) of the Op- Amp. 2. Feedback Resistor: A feedback resistor (Rf) is used to set the gain of the amplifier. 3. Output Current: The output current is the amplified version of the input current and is inverted. 4. Gain Formula: The current gain Ai is given by Iout=−Ai⋅ Iin, where Ai is the gain and Iin​ is the input current. 7.2.6 Summing Amplifiers Summing Amplifiers combine multiple input voltages into a single output voltage. They add the input voltages together, with a gain determined by the feedback resistors. Working Principle: 1. Input Voltages: Multiple input voltages are applied to the inverting terminal (−) through individual resistors. 2. Feedback Resistor: A feedback resistor (Rf) determines the gain and the combination of input voltages. 3. Output Voltage: The output voltage is the sum of the input voltages, each scaled by its corresponding resistor. 4. Gain Formula: The output voltage Vout​ is given by Vout=−(Rf/R1*V1+Rf/R2*V2+⋯ ), where Rf is the feedback resistor and R1,R2,⋯ are the input resistors. 7.2.7 Non-Inverting Summing Amplifier A Non-Inverting Summing Amplifier combines multiple input voltages into a single output voltage, where the output is in phase with the input signals. Working Principle: 1. Input Voltages: Multiple input voltages are applied to the non-inverting terminal (+) through resistors. 2. Feedback Network: A feedback network with resistors determines the gain and scaling of the combined inputs. 3. Output Voltage: The output voltage is the sum of the input voltages, without  inversion. 4. Gain Formula: The output voltage Vout is given by Vout=(1+Rf/Rin)(V1/R1+V2/R2+⋯ ), where Rf is the feedback resistor and Rin are the input resistors. 7.2.8 Differential Amplifier A Differential Amplifier amplifies the difference between two input voltages and rejects any common signals. Working Principle: 1. Input Voltages: Two input voltages are applied to the inverting (−) and non-inverting (+) terminals. 2. Amplification of Difference: The Op-Amp amplifies the difference between these two input voltages. 3. Rejection of Common Signals: Any signals common to both inputs are rejected. 4. Gain Formula: The output voltage Vout is given by Vout=Rf/Rin(V2−V1), where V1​ and V2 are the input voltages, and Rf and Rin​ are resistors in the feedback network. 7.2.9 (OP-Amp) as Adder/Subtractor An Op-Amp as Adder/Subtractor performs addition or subtraction of multiple input signals. Working Principle: 1. Adder Configuration: To add multiple signals, inputs are applied to the inverting terminal (−) with appropriate resistors, and the output voltage is the sum of these inputs. 2. Subtractor Configuration: To subtract, one input is applied to the inverting terminal (−) and the other to the non-inverting terminal (+), with the output being the difference between these inputs. 3. Gain Control: The gain for addition or subtraction is controlled by the feedback network of resistors. 4. Formula for Adder: Vout=−(Rf/R1*V1+Rf/R2*V2+⋯ ) 5. Formula for Subtractor: Vout=Rf/R1(Vin+ − Vin−)