Current flows as particles
The speed and number of particles follow the current in each wire. In parallel, more flows through the stronger branch; in AC, it moves back and forth.
Electric-circuit simulator · iOS / Android
See the
See the
current flow.
Place, wire, flip the switch. Particles of current start to flow and the bulb lights up. Move a value with a slider and the circuit is solved again on the spot. From Ohm's law to AC power factor, it is a circuit simulator you learn by doing.
sample / Bulb and switchLIVE
Try the switch
Source3.00V
Total current300mA
Total resistance10.0Ω
Power900mW
12kinds of parts
7sample circuits
290+automated tests check the answers
74languages
Features
The textbook diagram
comes alive.
Send current through the circuit diagrams that stood still on paper. You can see how much flows where, and why a bulb stays dark.
Solved again as you slide
Double-tap a part and move its voltage, resistance, capacitance or frequency. "What happens to the current if the resistance doubles?" is answered before you lift your finger.
Know why it fails
Short circuits, conflicting voltages, reversed or burned-out LEDs, overloaded bulbs. A stopped circuit tells you which part is wrong, and where.
The same symbols as your textbook
A battery's long line is +, a resistor is a rectangle, a bulb is ⊗. The circuit is drawn with the standard (JIS) symbols taught at school, so nothing is confusing.
Measure with meters
An ammeter in series, a voltmeter in parallel. Practise measuring the textbook way. The circuit's source voltage, total current, total resistance and power are always shown.
Tutorial and samples
Even first-timers can start at once: after the 6-page tutorial, a bulb circuit is already placed. Samples for series, parallel, LEDs, internal resistance and resonance are included.
AC · PRO
AC, too,
as waveforms.
Build RL / RC / RLC circuits with an AC source, capacitors and inductors, and see the voltage and current waveforms overlaid. Build AC problems from electrician and electrical-engineering exams as they are and check them.
- RMS values and phase — how many degrees the current lags the voltage, as numbers and waveforms
- Active, reactive and apparent power, power factor — see the effect of power-factor correction at once
- Series resonance — change the frequency and the current peaks at resonance
- DC and AC superposition — circuits with both are solved as they are
sample / AC and RL series VoltageCurrent
Source (RMS)100V 50Hz
Current / phase10.0A −53°
Power factor0.60
From school to exams
From school science to engineering exams.
The analysis engine is checked by automated tests based on middle- and high-school textbooks and on published exam problems. Kirchhoff's laws and conservation of energy are verified every time.
01
Middle-school science
- Ohm's law
- Series and parallel
- Power and brightness
- Ammeters and voltmeters
02
High-school physics
- Internal resistance
- Kirchhoff's laws
- Bridge circuits
- Diodes (LED)
03
Electrician exams
- Single-phase AC
- Impedance
- Power factor
- Active and reactive power
04
Electrical engineering theory
- RLC resonance
- Phase and phasors
- Apparent power
- Superposition
12 components
Build with 12 kinds of parts.
Free: up to 8 of the 9 DC parts. Pro adds the 3 AC parts, with no limit on the number.
BatteryFREE
BulbFREE
ResistorFREE
LEDFREE
SwitchFREE
WireFREE
AmmeterFREE
VoltmeterFREE
GNDFREE
AC sourcePRO
CapacitorPRO
InductorPRO
Screens
A lab bench in your pocket.
No account and no internet connection needed. Give your circuits a name and save them on your device.
Pricing
Free to start. Pro is a one-time purchase.
No subscription. Family Sharing is supported.
FREE
¥0
Build any DC circuit
- 9 DC parts (including the voltmeter and the bulb)
- Up to 8 parts
- 5 DC sample circuits
- 1 save slot
- Banner ad at the bottom of the screen
One-time
PRO
Buy onceno subscription
Price as shown in your store
- AC source, capacitor and inductor
- AC sample circuits (RL series, series resonance)
- Unlimited number of parts
- 5 save slots
- No ads
74 languages
In classrooms around the world.
Following your device's language, everything switches, from part names to the tutorial and the error explanations.
日本語English简体中文繁體中文한국어EspañolPortuguêsFrançaisDeutschItalianoРусскийУкраїнськаPolskiTürkçeالعربيةעבריתفارسیहिन्दीবাংলাதமிழ்తెలుగుไทยTiếng ViệtBahasa IndonesiaBahasa MelayuFilipinoNederlandsSvenskaNorskDanskSuomiΕλληνικάČeštinaMagyarRomânăKiswahiliisiZuluአማርኛქართულიՀայերենខ្មែរမြန်မာ…and 32 more
Flip
the switch.
For people who never liked electricity, and for those who teach it. DENDOU is free to start.