Push-Button Light
Press a button to turn your LED on. Let go to turn it off.
What you’ll learn
- How a switch breaks and completes a circuit.
- The difference between momentary buttons and toggle switches.
- Why every button on every device works the same way underneath.
What you need
| Item✓ | Qty | ~Cost | Where to buy | |
|---|---|---|---|---|
| 9V battery + snap clip | 9V battery + snap clip | 1 | GHS 23.00 | Any supermarket or hardware store. |
| 220 Ω resistor | 220 Ω resistor Look for red-red-brown stripes. | 1 | GHS 0.75 | Electronics shop or online (Amazon, Adafruit). Look for red-red-brown stripes. |
| Red 5 mm LED | Red 5 mm LED Any colour works; red is brightest. | 1 | GHS 1.50 | Electronics shop or online. Any colour works; red is brightest. |
| Half-size breadboard | Half-size breadboard | 1 | GHS 23.00 | Online (Amazon, Adafruit, AliExpress). |
| Jumper wires | Jumper wires | 4 | GHS 30.00 | Online — usually sold in packs of 30. |
| Tactile push-button | Tactile push-button 4-pin tactile switch — pairs of legs are joined inside. | 1 | GHS 4.50 | Electronics shop or online. 4-pin tactile switch — pairs of legs are joined inside. |
| TotalTotal | ~GHS 82.75 | |||
Build it step by step
Build the LED loop from Project 1
Same battery + resistor + LED placement, same returning wire to −.
Pull the +rail jumper
You’re going to insert the button between the + rail and the resistor.
Holes: +5, a5
Drop the button across the trench
Anchor it at e3 — the four legs straddle the trench so each pair stays on its own column strip.
Holes: e3, g3
Wire the + rail to one button leg
Jumper from +3 to a3. Now the + rail reaches the top of the button.
Holes: +3, a3
Wire the other button leg to the resistor
Jumper from j3 to a5. When you press the button, this connection completes.
Holes: j3, a5
Test it
Snap on the battery. The LED is dark. Press the button — it lights up. Let go — it’s dark again.
How it works
When you press the button, two metal pieces inside touch and current can flow. Let go and a tiny spring pushes them apart, breaking the loop. That’s a "momentary" switch — only on while held. A toggle switch (like a light switch on a wall) latches in place instead.
If something’s not working
LED stays on without pressing
- · Button is wired across two legs that are already joined inside (a1↔a2 or b1↔b2). Move one wire so it crosses the package.
Button does nothing
- · Loose jumper. Push it all the way in.
- · Button is rotated 90° — its legs only bridge in one orientation.
Try this next
Add a second button in parallel — either one turns the LED on.
Add a second button in series — both have to be pressed at the same time.