How Circuits Work: Chapter Guides
For each ElecLab chapter, this is what you try out in the puzzles, summed up with diagrams and worked numbers. The diagrams use the same parts as the game board, and the numbers come from the same circuit calculation as the game. Every guide links to that chapter's stages.
Chapter 1: Your First Circuit
How an LED Circuit Works: Closed Loops, Polarity, and Resistor Values (Ohm's Law)
Why an LED won't light, why it needs a resistor, and how to choose the resistor's value with Ohm's law, explained with diagrams and worked numbers.
Key termsclosed circuitLED polaritycurrent-limiting resistorOhm's law
Chapter 2: Series and Parallel
Series vs. Parallel Circuits: Current, Voltage, Combined Resistance, and Power with LEDs
How current and voltage behave in series and in parallel, shown through LED brightness, plus combined resistance, forward voltage, and power = voltage × current.
Key termsseries circuitparallel circuitcombined resistanceelectric power
Chapter 3: Switches and Logic
Switch Circuits: Series Is AND, Parallel Is OR, Push Buttons, and 3-Way Switches
Why switches in series make AND and in parallel make OR, with truth tables, plus momentary push buttons, SPDT switches, and how a staircase 3-way switch works.
Key termsAND circuitOR circuitpush button3-way switch
Chapter 4: Reading Voltages
Voltage Dividers, Voltmeters, and Pull-Up / Pull-Down Resistors
The voltage divider formula with worked numbers, how to connect a voltmeter, why a microcontroller input floats, and how to choose pull-up and pull-down resistors.
Key termsvoltage dividervoltmeterpotentiometerpull-up resistorpull-down resistorthermistor
Chapter 5: Capacitors
Capacitor Charging and Discharging: The RC Time Constant, Delays, and Afterglow
How a capacitor stores charge, the RC time constant and charging curve, how to make an LED light late or keep glowing, and electrolytic capacitor polarity.
Key termscapacitortime constantcharging and dischargingelectrolytic capacitor polarity