Interactive simulation

Stepper motor simulation

Full, half and wave drive — watch the coils fire and the rotor follow.

The blue arrow is the stator field: it jumps from pole to pole while the rotor eases after it. Watch half stepping land on positions between the poles, and wave drive energize a single coil at a time. The panel underneath is the current in each of the two windings: A+ and A- are the two ends of ONE coil, so its bar swings either side of zero instead of counting as two separate currents.

More simulations

TransformerTurns ratio in action — step the voltage up or down.
Transistor switchDrive an NPN into saturation and watch Q slide down the load line.
Transmission lineA step launched into a mismatched trace, bouncing until it settles — why a short track suddenly matters.
UART frameOne byte on a wire that carries no clock — and the receiver's own timer walking off the bit centres.
Zener regulatorIt holds the voltage — until the load asks for more than it can spare.
555 astableThe capacitor sawtooth and output square of the classic astable.
ADC quantizationHow many bits before the staircase disappears into the sine?
ADC sampling & aliasingSample a sine too slowly and watch the alias ghost appear.