Elec Class
learn electricity hands-on
Logic game · one grid a day
Every day, a new Lumière grid, our version of the Akari puzzle (also called Light Up), the same for everyone. Place the bulbs to light the whole circuit as fast as you can, and come back tomorrow for the next one.
One grid a day
Ready?
Loading today's grid…
The timer starts when you click. One game a day.
Click bulbRight-click crossClick again: blank
Next grid in --:--:--
Loading the leaderboard…
Players marked IA are house AI players, from slow to expert.
Each grid has its base points, according to its difficulty and size: from 100 for an easy 7 × 7 to 300 for a hard 10 × 10. They are multiplied by your speed, the day's reference time divided by your time: twice as fast, twice the points, with no cap. Even slowly, a solved grid earns at least half its base. The reference time is the median time of the AI players on the day's grid.
Three leaderboards, all by points: today's, this month's and all time. Playing every day counts more than being the fastest once. To appear, you need an account and a nickname; a time set without an account can be saved until midnight.
20 house players, such as Volta - IA or Curie - IA, play every grid: four very fast experts, mostly average players and a few slow ones. They are AIs, and their name says so: whatever your level, there is always someone to beat.
At home, lamps are wired in parallel: each one gets the full mains voltage, and if one burns out, the others stay on. In series, a single dead lamp would switch off the whole circuit. The resistor networks sheet explains why, with worked exercises.
A logic puzzle from the Japanese publisher Nikoli, also known as Light Up and Bijutsukan. Lumière follows its rules: one grid a day, the same for everyone, with a single solution.
Start the timer, then tap a square to place a bulb, a second time for a cross, a third time to clear it. The grid is solved when every white square is lit, no two bulbs see each other, and every number is respected.
No: anyone can play. An account is only needed to put your time on the leaderboard, with a nickname, until midnight the same day.
The grid's base points (100 to 300 depending on difficulty and size) multiplied by your speed: the day's reference time (the median time of the AI players) divided by your time. No cap, and at least half the base for a solved grid.
A 10 W LED bulb left on for one hour uses 10 Wh: one kilowatt-hour, the unit on your bill, is 100 hours of that lamp. A 60 W incandescent bulb giving the same light would use six times more. The electrical power sheet explains the calculation.
Yes: a grid takes 2 to 5 minutes, enough to start a lesson. The whole class gets the same grid on the same day, so times can be compared. See also the Teachers page.