| Motor Type | Permanent-magnet brushed DC motor with two armature terminals | PWM single-quadrant, half-bridge, or H-bridge drive | Match the motor's rated voltage, continuous current, peak current, and maximum speed | Speed control through average armature voltage; current limiting is recommended | Verify brush and commutator limits, stall current, thermal rating, and allowable switching frequency |
| Supply Voltage | 12 V, 24 V, 48 V, or another defined DC bus voltage | Drive voltage rating should exceed the highest continuous bus voltage and expected transients | Use the motor rated voltage as the operating reference; allow margin for supply variation and regeneration | Stable PWM output with undervoltage and overvoltage protection | For inductive loads, include a controlled current path and transient suppression; regenerated energy can raise DC-bus voltage |
| Continuous Current | Motor operates near its rated torque for extended periods | Continuous current rating at or above the motor's rated armature current | Continuous drive current should account for enclosure temperature, airflow, duty cycle, and wiring losses | Closed-loop current regulation improves torque repeatability | Current rating is thermal, not only electrical; derating may be required at high ambient temperature |
| Peak or Stall Current | Short acceleration, startup, jam, or high-inertia load | Current-limited PWM drive with a defined peak-current duration | At startup, motor current can approach V/R when back electromotive force is near zero | Fast overcurrent detection and configurable peak-current limiting | Do not use stall current as the continuous rating; check MOSFET, connector, shunt, and motor thermal limits |
| Load Profile | Constant torque, variable torque, intermittent duty, or repeated acceleration | Select the drive from the RMS current and peak torque demand, not only nominal power | Calculate RMS current over the complete operating cycle: IRMS = √(ΣI²t / Σt) | Programmable acceleration, deceleration, current limits, and duty-cycle profiles | Short high-current events may be acceptable if the motor and drive thermal time constants support them |
| Speed Regulation | Basic speed adjustment with moderate variation in load | Open-loop PWM for cost-sensitive applications | Define minimum and maximum speed, speed range, and expected load disturbance | Duty-cycle command; speed accuracy depends on motor characteristics and load | Open-loop control cannot reliably correct speed error caused by changing torque, friction, or supply voltage |
| Accurate Speed Control | Speed must remain stable when load or supply voltage changes | Closed-loop speed drive using an encoder, tachometer, or Hall feedback where appropriate | Specify feedback resolution, maximum feedback frequency, speed range, and allowable speed error | PI speed loop with inner current loop is commonly used for responsive control | Feedback wiring requires appropriate shielding, grounding, filtering, and fault detection |
| Positioning | Move to a target position, perform indexing, or synchronize motion | Bidirectional H-bridge with encoder feedback and position control | Define position accuracy, repeatability, backlash, travel range, and stopping distance | Position, speed, and current control loops with limit and home inputs | Mechanical compliance and gearbox backlash can limit system accuracy even when the drive is precise |
| Direction Reversal | Motor must run forward and reverse under controlled conditions | Two-quadrant or four-quadrant H-bridge | Confirm reverse current, reverse speed, braking torque, and allowable reversal frequency | Controlled acceleration through zero speed and direction interlocking | Never command opposing bridge switches simultaneously; include dead time and shoot-through protection |
| Braking Requirement | Motor must stop quickly or hold a controlled deceleration rate | Dynamic braking, regenerative braking, or four-quadrant drive according to the energy path | Estimate kinetic energy: E = ½Jω², then verify where braking energy will be dissipated or stored | Programmable deceleration and braking-current control | Regeneration can increase bus voltage; use a braking resistor, energy sink, or suitable battery/DC-bus management |
| Quadrant Operation | Forward motoring only | Single-quadrant drive | One direction of torque and speed is required | Forward speed or current control | Lowest complexity, but it cannot actively reverse torque or absorb regenerative energy |
| Quadrant Operation | Forward and reverse motoring, with controlled braking in both directions | Four-quadrant H-bridge drive | Drive must support positive and negative armature current and voltage | Bidirectional torque, regenerative braking, speed regulation, and positioning | Requires careful current sensing, commutation timing, dead-time control, and bus-energy management |
| Noise Sensitivity | Laboratory instruments, audio-adjacent systems, or low-noise mechanisms | Filtered PWM, low-ripple current control, or linear drive where efficiency permits | Define allowable acoustic noise, torque ripple, conducted emissions, and radiated emissions | Current smoothing and controlled switching transitions | Higher PWM frequency can reduce audible noise but may increase switching losses and electromagnetic interference |
| Efficiency Priority | Battery-powered, continuously operating, or thermally constrained equipment | Switch-mode PWM drive using low-loss power switches and appropriate gate control | Estimate drive losses, motor losses, duty cycle, and available cooling capacity | Efficient current and speed regulation with sleep or standby modes when applicable | Efficiency varies with current, switching frequency, bus voltage, motor speed, and cooling conditions |
| Environmental Conditions | Dust, moisture, vibration, chemicals, or ambient temperatures outside normal indoor conditions | Drive with suitable enclosure, conformal protection, connectors, and thermal derating | Specify operating temperature, humidity, ingress protection, vibration, shock, and altitude requirements | Temperature monitoring and fault reporting | The complete installation, including motor, cable, connectors, and enclosure, must meet the environmental requirement |
| Safety and Protection | Risk of jam, overload, unintended motion, or electrical fault | Drive with current limit, short-circuit protection, thermal protection, and controlled disable input | Define trip thresholds, response times, restart behavior, and safe state | Fault latching, emergency stop interface, overtemperature monitoring, and diagnostic output | Drive protection does not replace system-level risk assessment, guarding, fusing, or required safety functions |
| Command Interface | Analog, digital, pulse, or network-based machine control | Select an interface compatible with the controller and required update rate | Specify command range, resolution, latency, isolation, and noise immunity | Analog voltage/current, PWM command, pulse-direction, or industrial communication control | Check signal reference, isolation, scaling, fault handling, and communication loss behavior |
| Control Objective | Lowest cost and simplest integration | Single-quadrant open-loop PWM drive | Suitable for stable loads with modest speed accuracy requirements | Basic duty-cycle control and hardware current limiting | Use only when load variation, braking, and positioning requirements are limited |
| Control Objective | Balanced performance, efficiency, and adaptability | Closed-loop PWM drive with current and speed feedback | Specify motor constants, feedback device, current bandwidth, speed range, and load inertia | Current loop plus speed loop; programmable ramps and protection limits | Usually the most flexible choice for variable loads and repeatable machine motion |
| Control Objective | Fast, precise, reversible motion with energy recovery | Four-quadrant regenerative drive with position feedback | Size for peak torque, RMS current, braking energy, feedback resolution, and bus-energy handling | Current, speed, and position loops with regenerative braking | Higher cost and integration complexity are justified only when the motion profile requires them |