1. Introduction to Electronic Circuits Khansaa Almansor

2. Electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, Inductors and diodes, connected by conductive wires or traces through which electric current can flow.

3. Current is the movement of charges (such as electrons). Electric Current = Charge Passing Through A Given Area Time

6. Electric Generator Electrical Energy Mechanical Energy

8. Voltage : V – Potential to Move Charge (Units are volts) Current : I – Charge Movement (Units are amperes or amps) Resistance : R- A material that resists, but doesn’t stop the flow of current.(Units are ohms) Electric power: P- is the rate at which electric energy is transferred by an electric circuit. (Units are Watts)

9. Electric Circuit A series circuit is a circuit that has only one path for the current. A parallel circuit has more than one path for current to travel. Is a path that is made for an electric current

10. Electric Symbols An electronic symbol is a pictogram used to represent various electrical and electronic devices (such as wires, batteries, resistors, and transistors) in a schematic diagram of a circuit. Example:

11. Analog Digital Two types of Electrical Measurement tools:

12. A law stating that electric current is proportional to voltage and inversely proportional to resistance. Electric current is a flow of electric charge through a medium. Voltage is the potential energy that makes the electrical current flow in a circuit by pushing the electrons around. The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element I = V R Ohm’s Law: I (A) = V (V) R (Ω) (1) (2) (3) ×R I (A) = V (V)R (Ω) R × I R × I I (A) = V (V) R (Ω) What is Ohm’s Law?

13. Simple Electric DC Circuit Example: Calculate I R 5 Ω Vs 10 V Ohm’s Law I (A) = V (V) R (Ω) I (A) = 10 V 5 Ω I = 2 A I= 2 A >

14. Simple Electric DC Circuit Example: Calculate V R 5 Ω Vs Ohm’s Law = V = 15 V 3A × 5Ω V = 3 A I= 3 A > Vs 15 V I. R = V

15. Simple Electric DC Circuit Example: Calculate R R Vs 12 V Ohm’s Law I = V R R = 12 V 1.2 ΩR = 10 A I= 10 A > R 1.2 Ω R = V I

16. Series circuitParallel circuit

17. Series circuit > ITIT > I1I1 < I2I2 < I3I3 VTVT V1V1 V3V3 V2V2 NOTE: To measure Current, connect Ammeter in Series To measure Voltage connect Voltmeter in Parallel

18. Parallel circuit > ITIT > I1I1 < I2I2 < I3I3 VTVT V3V3 NOTE: To measure Current, connect Ammeter in Series NOTE: To measure Voltage connect Voltmeter in Parallel

19. Simple DC circuit project The following circuit is to glow a led which is with voltage 1.75V, and a 5mA minimum current flow. The source voltage or the battery we have is 12V. So to calculate the total current of the circuit we need to calculate the resistor of the led: R led =1.75V/5mA = 0.35KΩ I T =V T /R T = 12V/0.35KΩ=34.3mA The current will be too high for this led which may burn it. To solve this problem we need to add a resistor. To calculate the resistance which is needed, suppose I T is 5mA which exactly needed for making led glow. So R T will be: R T =12V/5mA=2.4KΩ If we have a resistor R in series then R=R T -R led =2.05KΩ So we need to add R=2KΩ to protect the led from burning.

20. Switches To turn the circuit ON/OFF we need switch. A switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another. Example: The following circuit is with Single Pole - Single Throw Switch (SPST) Switch is OFF Switch is ON

21. Example: The following circuit is with Single Pole Double Throw Switch (SPDT)

22. Example: The following is the circuit diagram of the Flashing Lights How it works? It consists of two transistors (Q1 & Q2), two capacitors (C1 & C2), two lights or LEDs,and four resistors (R1 to R4). When a 9V battery is connected to the circuit the transistors start to switch on and off in turn causing the LEDs to emit pulses of light.