Introduction
The document discusses the implementation of redundancy in miniature stepper motors, particularly for safety-critical applications such as aerospace and nuclear power plants. These applications require fault-tolerant motor designs to prevent catastrophic failures.

Importance of Redundancy
Redundancy is crucial in safety-critical systems to ensure reliability. It involves duplicating operations across multiple systems so that if one fails, another can take over. This is essential for systems heavily reliant on electric motor drives.

Fault-Tolerant Motor Specifications
A fault-tolerant motor should have higher redundancy with identical motor segments on the same shaft, electrically isolated phases to prevent short circuits, magnetically uncoupled windings to maintain performance, and physically isolated phases to prevent fault propagation and enhance thermal insulation.

Challenges with Traditional Solutions
Coupling two motors on the same shaft is a straightforward solution but has limitations such as increased cost, reduced efficiency due to friction and cogging, unpredictable resonance frequencies, and failure to meet size and weight requirements for aerospace applications.

FAULHABER Disc Magnet Motor Solution
The FAULHABER Disc Magnet motor offers a patented design with four independent windings, allowing for two Two-Phase PM stepper motors with isolated phases. This configuration reduces torque by 30% compared to standard motors but can achieve the same output torque with proper heat management and phase current increase.

Conclusion
The FAULHABER Disc Magnet motor design meets the specifications for a fault-tolerant, robust, and reliable motor with redundancy, crucial for safety-critical applications. This design requires minimal adaptation to provide a failure-free operation.