Motor-Driver Selection Workshop
Select a MOSFET, H-bridge or stepper driver from voltage, stall current, braking and thermal needs.
Learning objective
Select a MOSFET, H-bridge or stepper driver from voltage, stall current, braking and thermal needs.
Components and tools
- Development board
- Current-limited low-voltage supply
- Digital multimeter
- Oscilloscope or logic analyser
- Emergency power disconnect
Safety before motion
- Base selection on stall current and worst-case supply voltage.nDo not parallel driver channels unless explicitly supported.nCheck PCB copper, connector and wire current ratings.
Practical procedure
- Record motor voltage and stall current.nMultiply simultaneous stall load and add margin.nCheck driver continuous and peak current definitions.nCalculate conduction loss and assess cooling.nVerify flyback, current sense and fault protection.
Measurement checkpoints
| Checkpoint | Expected | Instrument | Safety limit |
|---|---|---|---|
| Current capacity | Above worst-case with margin | Datasheets/calculator | Thermal ratingnVoltage rating |
Troubleshooting
| Symptom | Check | Corrective action |
|---|---|---|
| Driver burns | Peak/thermal rating misunderstood | Recalculate loss and coolingnWeak torque |
Engineering sizing tools
Calculate before powering
Mandatory pre-start gate
Machine safety checklist
The simulated enable button remains locked until every item is confirmed.