Interactive tool + OEM report
24V GaN Robotic Actuator Controller
Estimate motor current and mechanical shaft power at a stated motor-shaft operating point, then use evidence-backed limits and an OEM validation checklist to assess a custom compact joint controller.
What the estimate can decide
A torque-speed point and motor torque constant can create a useful first-pass electrical brief for a 24V GaN robotic actuator controller. They cannot establish a controller rating or prove that GaN is the right switch technology. Treat the calculator as a screening step before device, thermal, and EMC design.
- Use motor-shaft torque ÷ Kt to estimate motor current in the Kt convention stated by the motor supplier. If only joint-side data is known, convert torque for the gear ratio and efficiency, and speed for the gear ratio, before entering motor-shaft values.
- Use the same motor-shaft torque × angular speed to estimate mechanical shaft power at that operating point; it is not DC input power.
- Select the power stage only after checking current waveform and duration, bus transients, device losses, PCB layout, cooling, and protection.
- Confirm claims on representative hardware. Published evaluation board results are examples tied to their own voltage, board, and cooling conditions.
Published September 25, 2026. Updated October 3, 2026. Public sources below describe device behavior and specific reference hardware; they do not specify a GanServo 24V actuator controller rating.
Method and evidence
The calculator uses three transparent relationships: estimated motor current = motor-shaft torque ÷ Kt; shaft power = motor-shaft torque × 2 × pi × rpm ÷ 60; and gross circular area = pi × (diameter ÷ 20)². The area is geometry only. The calculation excludes current convention conversion, motor saturation, inverter losses, thermal impedance, copper fill, mounting features, and edge clearances.
| Evidence | What it supports | Boundary for this project |
|---|---|---|
| Shaft power identity | Torque and angular speed define mechanical shaft power. | Does not include inverter or motor losses and requires torque and speed from the same operating point. See Texas Instruments, SPRA420A, Eq. 5, p. 6. |
| Motor torque constant | maxon defines its torque constant as the proportional relationship between motor current and output torque; this supports a first-pass T ÷ Kt current estimate. | Check the motor's current convention and account for losses, no-load current, saturation, and any gear stage. See maxon's motor-data guidance. |
| GaN switching behavior | EPC describes zero reverse-recovery charge for eGaN devices while noting that output capacitance is still charged and discharged each cycle. | This device-level property does not establish lower total losses or a cooler board than a selected silicon design. See EPC AN002. |
| Published motor-drive example | EPC reported 48V evaluation-board operation at switching frequencies up to 100kHz: 15A RMS without a heatsink and up to 20A RMS with natural-convection cooling and a heatsink attached. | Published June 4, 2026; these are board-specific 48V results, not a 24V custom-board rating or a universal cooling rule. See EPC's evaluation-board announcement. |
| System frequency trade-off | An Infineon motor-drive study reports reduced current ripple at higher switching frequency in its tested setup. | Outcome depends on motor and system conditions; validate switching loss, cable effects, EMI, and motor temperature on the intended design. See Infineon's 48V motor-drive study. |
From operating point to validated design
The estimator covers step 1. Device and board data plus prototype measurements are needed for steps 2 and 3.
Trade-offs and validation risks
| Decision area | What to compare | Practical next step |
|---|---|---|
| 24V vs 48V bus | At equal electrical power, a 24V bus carries twice the current of a 48V bus; at the same conductor resistance, its I²R loss is four times higher. Actual systems may use different wiring and power levels. | Compare supply range, wiring, connector limits, current sensing, protection, and power budget together. |
| GaN vs silicon | Compare device data and measured total-system losses at the intended bus voltage, current, dead time, switching frequency, and gate-drive settings. | Request a loss estimate with stated assumptions, then confirm on a thermal test fixture or representative assembly. |
| Fast switching and EMI | Parasitic inductance, switch-node slew rate, motor leads, and encoder routing can affect ringing and conducted or radiated interference. | Plan switch-node probing and encoder-noise checks; tune layout and switching edges against the device guidance. |
| Thermal and production risk | Package, copper, thermal interface, enclosure, duty cycle, and assembly process determine the result. Public sources do not establish this page's board temperature or production yield. | Agree thermal limits, inspection criteria, and sample test plans with the selected device supplier and manufacturing partner. |
OEM hand-off checklist
- Share the motor datasheet, torque-speed duty profile, Kt convention, bus range, transients, and current limits.
- Define board outline, stack-up, connector and encoder interfaces, enclosure, ambient range, and cooling contact.
- Agree component selection, protection response, assembly inspection, thermal test points, and EMC acceptance criteria before a pilot build.
Related work: review the 24V GaN motor-control PCBA for the broader control-board scope, or the 24V GaN FOC controller PCBA for current-sensing and control-loop considerations.
Frequently asked questions
Can this estimate tell me whether to use GaN or silicon?
No. It estimates motor current from torque and Kt, plus mechanical shaft power from torque and speed. Semiconductor choice requires comparing candidate devices, switching conditions, losses, layout, cooling, protection, and validation results.
Does a 24V bus make a robotic actuator inherently safe?
No. The nominal bus voltage alone does not establish system safety. Evaluate the complete electrical architecture, accessible circuits, energy storage, wiring, protection, and the safety requirements for the robot.
How should I read the estimated motor current?
The estimate is torque divided by the Kt value you enter. Motor datasheets use different current conventions, so check whether Kt is specified against phase peak, phase RMS, or another current definition before comparing the estimate with a controller rating.
Will a higher PWM frequency always reduce motor heating?
No. Higher frequency can reduce current ripple in a particular motor-drive system, but switching losses, motor construction, cables, control settings, and thermal paths also matter. Measure the complete system at the intended operating points.
What information is needed to estimate continuous current?
Define the motor phase-current convention, torque-speed duty profile, bus range and transients, candidate power stage, switching frequency, PCB stack-up, enclosure and cooling path, ambient range, and protection behavior. Then validate temperature and electrical margins on representative hardware.
Can encoder and firmware support be assumed?
No. Confirm the encoder protocol, electrical interface, timing, isolation needs, control-loop requirements, and fault handling against the selected MCU and the project requirements before freezing the design.
Inquiry Email
Include target torque/speed, quantity, and delivery location.