# Electricity and Electronics

**Mechanical Engineering**, Publication in the Diário da República - Despacho nº 14312/2015 - 02/12/2015

5 ECTS; 1º Ano, 2º Semestre, 15,0 T + 30,0 PL + 15,0 TP + 3,50 OT

**Lecturer**

- Francisco José Alexandre Nunes

**Prerequisites**

Not applicable.

**Objectives**

Provide students with the fundamental concepts used in the study of direct current and alternating current, allowing them to know and understand simple circuits with operational amplifiers, diodes, transistors and digital logic gates.

**Program**

1. Quantities and Fundamental Components of Electrical Circuits.

1.1. Constitution of the matter.

1.2. Definitions; fundamental electrical quantities: intensity of electrical current, electrical voltage.

1.3. International system of units.

1.4. Electric current shapes.

1.5. Resistance, resistivity, conductance and conductivity of a metallic conductor.

1.6. Measuring devices: voltmeter, ampmeter, ohmmeter.

1.7. Materials used in electricity: conductors, semiconductors and insulators.

1.8. Ohm's law.

1.9. Voltage sources and current sources.

1.10. Joule's law. Power absorbed and supplied by a circuit element.

2. Kirchhoff's laws.

2.1. Knot, mesh and branch concepts.

2.2. Kirchhoff's voltage law.

2.3. Kirchhoff's current law.

2.4. Association of resistances in series and in parallel.

2.5. Voltage and current dividers.

2.6. One mesh circuits analysis.

2.7. Analysis of simple circuits with mixed association of resistances.

2.8. Systematic application of Kirchhoff's laws.

2.9. Use of the simulation software for electrical and electronic circuits LTSpice.

3. Fundamental Theorems of Electrical Circuits.

3.1. Cancellation of generators.

3.2. Superposition theorem.

3.3. Thevenin and Norton theorems.

3.4. Source transformation.

3.5. Maximum power transfer theorem.

4. Single-phase sinusoidal alternating current.

4.1. Why alternating current.

4.2. Characterization of alternating quantities.

4.3. Laboratory measurement of alternating quantities - the oscilloscope and the signal generator.

4.4. Analytical representation and vector representation of alternating current.

4.5. Phase-shift between alternating sinusoidal quantities.

4.6. Representation of alternating sinusoidal quantities by phasors.

4.7. Alternating current circuit elements: resistor, capacitor and inductor.

4.8. Impedance, reactance and admittance.

4.9. Active, reactive and apparent powers.

4.10. Power factor.

4.11. RLC circuits.

4.12. Power factor compensation.

5. Operational Amplifier (OpAmp).

5.1. Voltages and currents at the OpAmp terminals.

5.2. Voltage follower.

5.3. Inverter circuit.

5.4. Summing circuit.

5.5. Non-inverter circuit.

5.6. Difference amplifier.

5.7. Instrumentation amplifier.

5.8. Comparator.

6. Diode.

6.1. Type N and Type P semiconductors.

6.2. P-N junction.

6.3. Direct bias.

6.4. Reverse bias.

6.5. Logic circuits with diodes.

6.6. Half-wave and full-wave rectifier.

6.7. Capacitive filtered rectifiers.

6.8. Limiting circuits with diodes.

6.10. Special diodes: zener diode (voltage regulators), Schottky diode, LED and photodiode.

7. Transistors (BJT and MOSFET).

7.1. Bipolar Junction Transistor (BJT).

7.1.1. Operating states: off, active region and saturation.

7.1.2. Common Emitter (EC) configuration.

7.1.3. Bias and stabilization.

7.1.4. The transistor as an amplifier element.

7.1.5. The BJT as a current source.

7.1.6. Fundamental applications of a transistor.

7.1.7. The BJT as a switch.

7.1.8. Phototransistor and optoelectronic isolators.

7.2. Field Effect Transistor (MOSFET).

7.2.1. Operating states: off, saturation and triode.

7.2.2. Common Source Configuration.

7.2.3. Bias and stabilization.

7.2.4. The MOSFET as an amplifying element.

7.2.5. The MOSFET as a switch.

8. Digital logic circuits.

8.1. Binary code.

8.2. Elementary logic gates.

8.3. Boole algebra.

8.4. Truth tables.

8.5. Karnaugh maps.

8.6. Synthesis of combinational logic circuits.

8.7. Use of the Logisim simulation software.

**Evaluation Methodology**

Final grade: NF = CT * 60% + CP * 40%

(min. 10/20)

Theoretical component: CT = AC or EF

(min. 9/20)

continuous assessment: AC = TE * 2/3 + TI * 1/3

TE - tests (min. 8/20); I - individual assignments

final exam: EF

Practical component: CP - practical work (LABs)

(min. 10/20)

**Bibliography**

- Meireles, V. (2010). *Circuitos Eléctricos*. -: Lidel

- Bates, -. e Malvino, -. (2016). *Eletrônica*. -: Mc Graw Hill

- Dias, M. (2012). *Sistemas Digitais Princípios e Prática*. -: FCA Editora de Informática, Lda

- Nunes, F. (0). *Eletricidade e Eletrónica LEM (apresentações das aulas, problemas e guias de laboratório)*. Acedido em 1 de março de 2021 em https://teams.microsoft.com/_#/school/files/19%3A36375d911580413b93a7ce1f2a2b626e%40thread.tacv2?threadId=19%3A36375d911580413b93a7ce1f2a2b626e%40thread.tacv2&ctx=channel&context=Apresenta%25C3%25A7%25C3%25B5es&rootfolder=%252Fteams%252FEletricidadeeEletrnica-LEM%252FMaterial%2520de%2520Aula%252FApresenta%25C3%25A7%25C3%25B5es

**Method of interaction**

Theoretical lectures. Theoretical-practical classes with resolution of exercises. Laboratory practical classes where circuits are assembled, tested and simulated exemplifying the application of the studied theoretical concepts.

**Software used in class**

LTSpice; Logisim.