Electronic Components, One Build at a Time

Starter · about 6 hours · 23 lessons and builds · for complete beginners

Know the fourteen components every circuit is made of: read them, test them with a meter, and use each one, ending with a solar-powered automatic light you built yourself.

One circuit that grows: resistor and LED first, then a component per lesson until it is a solar, dusk-sensing, motion-triggered timed lamp.

Before you start: None: start here

Start the course in the labFree. Sign in only if you want your progress on every device.

Module 1: Passive parts: R, switch, pot, diode, capacitor

• 1. Resistor and LED: the first circuit
• 2. Adding a switch
• 3. Potentiometer: a dimmer
• 4. Diode: reverse-polarity protection
• 5. Capacitor: a soft fade-out

Extra practice:

• Ohm’s law
• LED and its series resistor
• Capacitor charging

Module 2: Sensing and switching: LDR, transistor

• 6. LDR: sensing light
• 7. Transistor: the light switches itself

Extra practice:

• Light sensor (LDR divider)
• Transistor as a switch

Module 3: Power and decisions: regulator, comparator

• 8. Voltage regulator: a 12 V supply and a steady 5 V
• 9. Comparator: a clean decision at dusk

Extra practice:

• 12 V → 5 V regulators
• Comparator with a light sensor

Module 4: Real loads and automation: relay, PIR, 555, buzzer

• 10. Relay: switching a real lamp
• 11. PIR sensor: only when someone is there
• 12. 555 timer: stay on after they pass
• 13. Buzzer: an alarm mode

Extra practice:

• Inductive load and the flyback diode
• 555 monostable (one-shot timer)

Module 5: Off-grid: solar, controller, battery

• 14. Solar: the light runs off-grid