BUILD CARD · EASY

Two Lamps in Parallel

Connect two lamps across the same two supply rails and compare them with the series version.

Learning goals

Build and check a 10×7 snap-grid circuit from a visual diagram.
Parallel lamps share the same supply voltage while current divides between branches.

FINAL CIRCUITBOARD 10×7

02 / PARTS CHECK

Parts list

03 / ASSEMBLY

1
Disconnect the battery and clear the base grid before placing any part.
2
Match the final diagram one grid position at a time, placing connecting wires and lower layers first.
3
Check the direction of every LED, diode, transistor, battery, and other terminal-sensitive part.
4
Press every shared snap firmly, check that no wire shorts the battery, then connect power last.

04 / FIELD NOTES

Parallel branches connect across the same two supply nodes.

Each lamp receives approximately the full battery voltage, so both are brighter than in the series drawing.

Parallel branches draw more total current from the battery.

THE IDEAParallel lamps share the same supply voltage while current divides between branches.

05 / TEST

What to do: Close the switch, compare both lamp brightness levels, then remove one lamp with power disconnected.
What to expect: Both lamps glow at similar brightness; after one is removed, the other branch can still operate.

06 / SAFETY

07 / TROUBLESHOOTING

08 / FREQUENTLY ASKED QUESTIONS

What is the main idea behind this circuit?

Parallel lamps share the same supply voltage while current divides between branches.

What should I check first if it does not work?

Confirm the lamps occupy separate branches rather than one line.