Data‑driven engineering builds on core electrical engineering concepts. From the smallest sensor to industrial power grids, understanding how electricity is generated, transmitted, stored and controlled is critical for safe, efficient and reliable systems. The modules below provide an integrated overview of circuits, actuators, motors, sensors, supervisory control systems, power generation, energy storage and electrical safety.

Electrical and electronic devices convert physical phenomena into signals and actions. Sensors measure variables such as temperature or pressure and convert them to voltages or currents. Actuators such as motors, valves, heaters and relays receive electrical signals and produce movement or switching. These building blocks operate within circuits governed by Ohm’s law, Kirchhoff’s laws and basic component behaviors. Supervisory control and data acquisition (SCADA) systems coordinate signals and actions across industrial networks. Power systems produce and distribute electricity to run equipment, and energy storage balances supply and demand while powering mobile devices and electric vehicles. Underpinning everything is electrical safety with procedures and design practices that protect people and equipment from harm.

1️⃣ Circuits ⚡

Electrical circuits form the foundation of instrumentation and control. They link sensors and actuators to controllers, convert physical signals to voltages or currents, and provide the power needed to drive valves or heaters. Key concepts include:

• Voltage (V), Current (I) and Resistance (R). Voltage is the potential difference that pushes charge through a circuit. Current is the rate at which charge flows. Resistance quantifies the opposition to current. Ohm’s law relates them as `V = I R`.
• Capacitance and Inductance. Capacitors store charge and the current through a capacitor is `I = C {dV}/{dt}`. Inductors store magnetic energy and oppose changes in current and the voltage across an inductor is `V = L {dI}/{dt}`.
• Kirchhoff’s Laws. The sum of currents entering a node equals the sum leaving it (KCL), and the algebraic sum of voltage drops around any closed loop is zero (KVL). These laws allow complex circuits to be analyzed systematically.
• Fundamental components. Resistors dissipate energy as heat, capacitors and inductors store energy, and diodes conduct primarily in one direction and are used for rectification. Light‑emitting diodes (LEDs) emit light but require a current‑limiting resistor.
• Breadboards and Prototyping. Breadboards let engineers build and test circuits without soldering. Horizontal rows serve as power rails, while vertical columns connect component leads. Simple experiments include sizing resistors for LEDs, timing RC circuits, and rectifying AC to DC using diodes and capacitors.

Understanding circuits prepares students to model and simulate systems, design sensor conditioners and build safe power supplies.

2️⃣ Actuators ⚙️

Actuators convert electrical signals into physical actions such as motion, force, heat or switching. They range from tiny servos in robotics to solenoid valves and industrial pumps. This module covers:

• Types of actuators. Servos and stepper motors provide precise positioning. Electromagnetic relays and solid‑state relays switch high currents. Transistors (BJTs and MOSFETs) amplify or switch signals. Operational amplifiers (op‑amps) create analog controllers. Valves, pumps, blowers and heaters regulate flow, pressure and temperature.
• Transistors and Op‑amps. BJTs act as current‑controlled switches or amplifiers: a small base current controls a larger collector current. The current gain β typically ranges from 50–200. MOSFETs are voltage‑controlled and a gate‑to‑source voltage above a threshold creates a conductive channel and current flows according to `I_d = ½ k(V_{gs} − V_{th})^2`. Op‑amps are high‑gain differential amplifiers. With negative feedback, an inverting amplifier has gain `A_v = −R_2 / R_1` and a non‑inverting amplifier has gain `A_v = 1 + R_2 / R_1`.
• Practical considerations. Actuator response time, monitoring, saturation limits and thermal management influence system performance. Simple projects, such as designing a transistor switch for a solenoid or an inverting op‑amp circuit, teach how to calculate base resistors, choose power ratings and avoid saturating the supply.
• Applications. Actuators appear in home automation, robotics, prototyping and industrial process control. Safety requires selecting components with appropriate voltage and current ratings, providing heat dissipation and following safe wiring practices.

3️⃣ Motors 🌀

Motors are the workhorses of process equipment, converting electrical energy into mechanical rotation. They drive pumps, fans, compressors and valve actuators. Key topics include:

• Motor types. DC motors are simple and respond to applied voltage. AC induction motors are robust and efficient. Stepper and servo motors move in discrete steps for precise positioning.
• Torque, speed and power. Torque (T) is rotational force (N·m), speed (ω) is angular velocity, and power is `P = T ω`. A motor delivering 5 N·m at 100 rad/s outputs 500 W.
• Process control applications. Pump flow is proportional to motor speed. Valve actuators position valve stems. Compressors and fans rely on motor speed for throughput and pressure.
• Dynamics and control. Motors have inertia and damping, so input voltage or frequency changes produce delayed mechanical responses. Starting torque limits can cause stalls. AC motors use variable frequency drives (VFDs) to control speed. DC motors use pulse‑width modulation (PWM). Oversizing motors wastes energy and reduces controllability.
• Simulation. Simple motor models use parameters like inertia (J), damping (b), motor constant (K), resistance (R) and inductance (L) to simulate speed response to step voltages. Such models teach the relationship between electrical inputs and mechanical outputs.

4️⃣ Sensors 📟

Sensors detect physical quantities and convert them into electrical signals. Accurate measurement is the foundation of feedback control, optimization and data‑driven decisions. Highlights include:

• Transduction mechanisms. Resistive sensors such as strain gauges, pressure diaphragms, RTDs and thermistors change resistance. Capacitive sensors vary capacitance with distance or pressure. Inductive and magnetic sensors (LVDTs, Hall‑effect) convert position or current into voltage. Piezoelectric sensors generate charge when stressed. Electrochemical sensors (pH electrodes, gas analyzers) output voltages or currents. Frequency‑output sensors produce pulses proportional to flow or distance.
• Signal conditioning. Raw sensor signals are often microvolts or millivolts and susceptible to noise. Instrumentation amplifiers boost signals, low‑pass filters remove noise, and linearization or temperature compensation corrects nonlinearities. Signal conditioners scale outputs to standard ranges like 4–20 mA, 0–10 V or 3–15 psig so that any controller can interpret them.
• Industrial signal standards. The 4–20 mA current loop dominates because current is immune to voltage drops and 0 mA indicates a fault. Voltage ranges (0–10 V, 1–5 V) are simple but susceptible to noise. Pneumatic signals (3–15 psig) are used in hazardous areas. Digital fieldbus protocols (HART, Modbus, Profibus, Foundation Fieldbus) and wireless standards (ISA100, Wi‑Fi, Bluetooth) allow bidirectional communication.
• Microcontroller interfaces. IoT platforms like Arduino and ESP32 read analog voltages (0–1 V, 0–3.3 V, 0–5 V), count pulses or measure duty cycles for frequency‑based sensors, and communicate via I²C, SPI or UART/1‑Wire buses to digital sensors. Many breakout boards integrate the signal conditioning for direct digital output.
• Applications. Sensors enable real‑time monitoring in electrorefining (temperature, cell voltage, composition), bioreactors (pH, dissolved oxygen, pressure) and polymerization reactors (temperature, pressure, viscosity). Proper selection of materials and housings ensures performance in corrosive or high‑temperature environments.

5️⃣ SCADA Systems 🖥️

Supervisory Control and Data Acquisition (SCADA) systems coordinate complex industrial operations. They collect real‑time data from sensors and actuators, transmit the data over networks and provide supervisory control via human–machine interfaces. SCADA elements include:

• Remote Terminal Units (RTUs) / Programmable Logic Controllers (PLCs). RTUs/PLCs gather signals from field devices, perform limited control and relay data to the SCADA master. They handle digital and analog I/O and execute control algorithms.
• Communication networks. Fieldbus, Modbus, OPC‑UA and industrial Ethernet connect devices, controllers and SCADA hosts. Digital inputs handle binary signals (push buttons, limit switches, proximity sensors) at 24 VDC or 120 VAC. Input modules may be sinking or sourcing. Digital outputs drive relays, solenoids and indicators and outputs can be relays, triacs or transistors.
• Analog inputs and outputs. Analog inputs measure continuously variable signals (voltage, current, temperature, pressure, flow) and convert them via ADCs and typical ranges are 0–10 V, 4–20 mA or ±10 V. Analog outputs use DACs to drive control valves, variable‑speed drives and heaters.
• Protocols. Modbus is an open, simple client/server protocol with register‑based data exchange. Modbus supports RTU, ASCII and TCP variants but lacks built‑in security. OPC and OPC UA extend interoperability and add platform independence, information modelling and security and OPC UA supports both client/server and publish/subscribe models.
• Distributed vs central control. PLCs excel at discrete logic and machine sequencing, with a central processor and modular I/O. They offer fast scan times and ruggedness. Distributed Control Systems (DCS) coordinate thousands of measurements in continuous or batch processes using multiple controllers connected over redundant networks. They support advanced control, alarm management and recipe management. The distinction between PLCs and DCS is blurring as modern programmable automation controllers (PACs) combine their features.

SCADA systems are the backbone of modern industry, enabling operators to monitor and control large facilities safely and efficiently.

6️⃣ Power Systems 🏭

Power engineering concerns the generation, transmission and distribution of electricity. Reliable and affordable power enables modern society and supports the growth of data‑intensive industries.

• Generation and distribution. Utility‑scale plants convert chemical, nuclear or renewable energy into electricity. Steam turbines driven by fossil fuels or nuclear fission, hydro turbines powered by water and wind or solar plants generate AC electricity. High‑voltage transmission (hundreds of kilovolts) reduces current and minimizes resistive losses. HVDC links connect unsynchronized grids and reduce reactive power. U.S. electricity production (≈4.18 trillion kWh in 2023) came from ~60 % fossil fuels, ~19 % nuclear and ~21 % renewables.
• Power and energy calculations. Electrical power is `P = V I` or `P = I² R = {V²}/R` for DC circuits. Energy is the product of power and time: `E = P t`. In AC systems, real power (P) is the useful work, reactive power (Q) arises from energy storage in inductors/capacitors and apparent power (S) is the product of RMS voltage and current. Power factor (pf = P/S) quantifies the efficiency of energy use. Three‑phase power formulas introduce a √3 factor to account for line‑to‑line voltages. Engineers calculate line losses (I² R) and voltage drop to size conductors and design efficient transmission.
• Billing and costs. Large consumers pay demand charges based on peak power and energy charges per kilowatt‑hour. Example calculations show that demand charges can dominate the bill for a data center on Rocky Mountain Power’s Schedule 8. In deregulated markets (ERCOT), costs derive mainly from energy and delivery rates.
• Energy mix and trends. Natural gas plants provide fast ramp‑up and accounted for ~43 % of U.S. generation in 2023. Coal’s share fell from ~45 % in 2010 to ~16 % by 2023 while nuclear provided ~18.6 %, hydro about 5.7 %, and wind and solar grew rapidly, with wind supplying ~10.2 % and solar increasing nearly eightfold since 2015. Diversified generation improves reliability and reduces environmental impact.

Understanding power systems equips engineers to analyze demand, design sustainable generation portfolios and evaluate the cost impacts of energy and demand charges.

7️⃣ Energy Storage 🔋

Energy storage balances supply and demand and empowers mobile or remote systems. As renewable generation grows, storage technologies absorb excess power when production is high and release it during peak demand.

• Why storage? Pumped‑storage hydropower (PHS) accounts for ~95 % of utility‑scale storage. Battery capacity grew from 0.047 GW in 2010 to 29 GW by early 2025, with projections of ~65 GW by 2026. Energy storage also powers electric vehicles (EVs) that consume around 0.346 kWh/mi and enables combined heat and power (CHP) systems that achieve 65–80 % efficiency by using waste heat.
• Pumped‑hydro storage. Water is pumped uphill when electricity is cheap and released through turbines when demand peaks. Potential energy is `E = m g h`. Round‑trip efficiency is 70–85 %, so only about 80 % of the energy is recovered. A reservoir holding 2 million m³ of water at a 100 m height stores ≈544 MWh, of which ~435 MWh is usable at 80 % efficiency.
• Battery storage. Energy is the product of cell capacity (Ah) and voltage. For a lithium‑ion cell with 3.6 V and 3.0 Ah, `E_{cell} ≈ 10.8 Wh`. The energy of a pack is `E_{pack} = N_{cells} × E_{cell}`. Batteries offer fast response and high efficiency (~90 %), but limited life and higher cost per MWh. EV packs contain hundreds or thousands of cells. For example, an EV with a 400 V pack built from 96 cells stores ~1 kWh.
• Capacitors and supercapacitors. Capacitors store energy electrostatically: `E = ½ C V²`. Supercapacitors have high power density and can smooth short‑duration load variations but have lower energy density than batteries.
• Hydrogen storage. Hydrogen’s lower heating value is ~33 kWh/kg, over 100 × the energy density of lithium‑ion batteries, but round‑trip efficiencies are <50 % due to losses in electrolysis and fuel cells. Hydrogen is suited for seasonal or long‑duration storage.
• Co‑generation and thermal storage. CHP systems produce electricity and useful heat, achieving total efficiencies of 65–80 %. Coupling CHP with thermal or battery storage allows facilities to shift electricity use, reduce fuel consumption and lower emissions.

Case studies compare pumped‑hydro and battery systems: a 600 MWh pumped‑hydro plant (80 % efficiency) and a 600 MWh lithium‑ion system (90 % efficiency) deliver the same energy, but the battery occupies less space and provides faster response, while pumped hydro has lower cost per MWh and longer life.

8️⃣ Electrical Safety 🚨

Working with electricity requires rigorous safety practices. Improper design or handling can lead to shocks, burns, fires or equipment damage. This module emphasizes:

• Lock‑Out/Tag‑Out (LOTO). Before maintenance, identify all energy sources, isolate the equipment from power, apply locks and tags, verify de‑energization and ensure only the person who installed the lock removes it. LOTO prevents unexpected energization and protects personnel.
• Safe voltage levels. According to OSHA, DC voltages above 50 V and AC voltages above ~30 `V_{rms}` are hazardous. Currents as low as 100 mA can be fatal. Low‑voltage supplies (e.g., USB at 5 V) are generally safe, but moisture or broken skin reduces resistance, so circuits should be insulated and grounded.
• Heat dissipation and fail‑safe design. Power electronics, motors and transformers generate heat. Components must be rated appropriately and cooled with heat sinks or ventilation. Systems should default to a safe state on fault (e.g., valves close on power loss) using normally closed designs or protective relays.
• Arc flash safety. Electrical faults can cause explosive arc flashes. Mitigation includes arc‑flash analysis, labelling panels with incident energy and required personal protective equipment (PPE), and using current‑limiting fuses and relays.
• Grounding, fuses and circuit breakers. Ground‑fault circuit interrupters (GFCIs) detect leakage currents and disconnect power. Proper insulation prevents accidental contact. Routine inspection identifies worn cords or loose connections. Grounding provides a safe path for fault currents and fuses / circuit breakers open circuits when current exceeds safe limits.

Safe engineering practice requires training, adherence to codes and continuous vigilance. Following LOTO, using low‑voltage designs, incorporating appropriate protection devices and performing regular maintenance protect both people and equipment.

This overview highlights the interconnected electrical engineering topics essential to Data‑Driven Engineering. Mastery of circuits, actuators, motors, sensors, SCADA systems, power systems, energy storage and electrical safety enables engineers to design, build and operate sophisticated systems that are efficient, reliable and safe.