Glossary · Motion control and drives
Chopper mode
Also known as: Current chopping, Chopper drive
German: Chopper-Modus
In stepper motor drivers, a chopper mode is the method by which the driver regulates the phase currents with pulse-width modulation, switching the supply voltage on and off at high frequency and choosing how the current decays, so that the winding current follows its target value; modes differ in noise, precision and dynamic behavior.
- Motion control
In one sentence
A chopper mode is the PWM method a driver uses to regulate stepper phase currents; modes trade quiet running against precision and dynamics.
Example
A 3D printer's axis drivers use a quiet voltage-mode chopper at low speed and switch to a cycle-by-cycle current chopper when the print head moves fast.
How it applies
- Engineering: Classic choppers regulate the current cycle by cycle with slow, fast or mixed decay. Quiet modes regulate by voltage and are almost silent at low speed; precise, dynamic modes regulate the current directly and cope better with high speed and changing loads. Vendors name their modes, for example ADI Trinamic StealthChop (quiet) and SpreadCycle (precise, dynamic).
- Commissioning: Chopper parameters (off time, hysteresis, blank time, switching threshold between modes) affect noise, heat and torque. Wrong values cause audible whine, vibration or current ripple.
- Operation: Quiet modes can lose torque or become unstable with sudden load changes; some ICs switch mode automatically above a set speed.
- Documentation: Describe the chopper mode by its behavior (quiet, precise, dynamic) and name the vendor term only as the setting label. Keep in mind that product and mode names change and belong to the vendor.