Mounting & Cooling
This page provides mounting instructions and thermal management guidelines for the KRIOSâ„¢ MINI electronic speed controller.
Capacitor Installation (PM0A92-XX-B Variants)​
KRIOSâ„¢ MINI PM0A92-XX-B variants ship without onboard electrolytic capacitors. An external capacitor must be soldered across the power input pads before use to filter voltage ripple and protect the ESC from electrical damage.
Running a PM0A92-XX-B variant without an external capacitor can cause excessive voltage spikes and ripple, leading to ESC failure. Always install the capacitor before connecting power.
Recommended Capacitors​
The following capacitors are validated and recommended by SIGSA for use with PM0A92-XX-B variants:
| Specification | CAPXON ZH Series | Rubycon ZLH Series |
|---|---|---|
| Part Number | ZH471M035G160A | 35ZLH470M10X16 |
| Capacitance | 470 µF | 470 µF |
| Voltage Rating | 35 V | 35 V |
| Type | Electrolytic (Low ESR, High Ripple Current) | Electrolytic (Low ESR, High Ripple Current) |
Soldering Procedure​
- Identify the power input pads on the KRIOSâ„¢ MINI PM0A92-XX-B board (positive and negative).
- Prepare the capacitor leads — trim to length and tin with solder.
- Observe polarity — align the capacitor's negative lead (marked with a stripe) to the negative pad.
- Solder the capacitor leads across the power input pads.
- Inspect the joint for proper wetting and ensure no solder bridges to adjacent pads.
Keep capacitor leads as short as possible to minimize inductance. Apply modest strain relief if the capacitor may experience vibration during operation.
Mounting​
The KRIOSâ„¢ MINI does not include mounting holes due to compact design, SIGSA recommends using electronics adhesive or zip-ties to secure the esc in place.
Electrical Isolation​
Maintain a minimum 0.6 mm air gap between exposed contacts and any conductive materials in the mounting assembly. All thermal interface materials must be electrically insulative to prevent short circuits.
Environmental Protection​
The KRIOSâ„¢ MINI is a bare board with numerous exposed connections. Contact with water, heavy moisture or significant amounts of dust/particulate can result in unit failure.
Ensure appropriate environmental protection is implemented based on your aircraft's operating conditions:
- Use conformal coating or heat shrink tube for moisture protection
- Consider enclosures for dusty environments
- Ensure adequate ventilation for cooling airflow
Thermal Management​
The KRIOSâ„¢ MINI's compact size and high power density require effective cooling to maintain components within safe operating temperatures.
Cooling Recommendations​
The KRIOS™ MINI has a particularly high power density, making effective cooling essential. To ensure continuous operation at rated phase current, your cooling solution must effectively dissipate heat from the unit to ambient. The recommended temperature limit for long term reliability is 75℃.
- Passive Cooling: Mount to a metal heatsink or aircraft frame with adequate thermal mass. SIGSA recommends placing a heatsink on top of the MOSFET packages for optimal heat dissipation.
- Active Cooling: For high-current applications, ensure direct airflow over the ESC.
- Thermal Interface Material: Use high-quality thermal pads or paste between the ESC and heatsink.
Monitor ESC temperature during initial testing to ensure your cooling solution is adequate for your specific application.