Inductive Rotary Joint Segmented Secondary Winding for CT Scanner Voltage Stability
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Solution Overview
Problem
Inductive power couplers in CT scanners face issues with high output voltage increases during low load conditions due to parasitic resonant circuits, leading to potential damage of electronic components, and require a dummy load to mitigate this, which is inefficient and costly.
Innovation Solution
The design incorporates at least two secondary windings wound in the same direction with a common connection point and capacitors, along with a new rectifier circuit that acts as a voltage doubler, reducing parasitic capacitance and stray inductance, and optionally includes a DC/DC converter to manage output voltage, thereby minimizing the need for a dummy load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single secondary winding is used in the inductive power coupler, then the device structure is simple, but parasitic capacitance and stray inductance cause voltage increases under low load conditions
Solution Approach 1:
The secondary winding is divided into multiple segments (first secondary winding and second secondary winding) with different tap points. This segmentation reduces the parasitic capacitance and stray inductance in each segment, thereby preventing voltage increases under low load conditions while maintaining a relatively simple overall structure.
Solution Approach 2:
Different tap points are provided on the secondary winding segments to optimize the impedance matching and reduce parasitic effects locally. By strategically placing tap points at specific locations along the winding segments, the patent achieves better voltage regulation without requiring complete redesign of the entire winding structure.
2Stability of the object's composition
If a dummy load is added to prevent output voltage increase, then voltage stability is improved, but device complexity and heat dissipation requirements increase
Solution Approach 1:
The patent extracts and eliminates the need for dummy load components by redesigning the winding structure itself. The segmented secondary windings with optimized tap points inherently prevent voltage increases, removing the requirement for additional dummy load resistors and associated cooling systems.
Solution Approach 2:
The patent converts the potentially harmful parasitic capacitance and stray inductance into beneficial impedance characteristics by carefully designing the segmentation and tap point locations. This transforms what would normally require compensating dummy loads into an inherent voltage-stabilizing feature of the transformer design.
3Power
If high power is transferred to the X-ray tube, then imaging quality is improved, but the parasitic resonant circuit effects become more pronounced
Solution Approach 1:
The segmented winding structure with multiple tap points provides dynamic adaptability for different power levels. By selecting appropriate tap points based on the required power output, the system can optimize performance across a wide range from low-power idle states to high-power imaging operations, minimizing parasitic resonant effects at each operating point.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration reduces the energy stored in parasitic capacitance, lowers the required dummy load, and decreases heat dissipation, preventing output voltage increases and reducing the need for additional components like high-power resistors and cooling systems.
Implementation Method 1
a primary winding (110) supplied by an inverter (120) with an AC signal
Implementation Method 2
Each of the first and the second winding outputs is connected to a pair of rectifiers (221-224)
Implementation Method 3
The stray inductance or parasitic inductance in conjunction with the parasitic winding capacitances causes a parasitic resonant circuit
Data Source
AI summary
An inductive power transfer circuit comprises an inductive rotary coupling with a primary side rotatably arranged a secondary side. The primary side has a primary winding and the secondary side has at least two secondary windings. The secondary windings deliver a signal with the same phase and are connected at one end to a pair of capacitors, being further connected to a positive output and a negative output. The other ends of the secondary windings each are separately connected to a pair of rectifiers connected in forward direction to the positive output and in reverse direction to the negative output.By paralleling multiple secondary windings and rectifier circuits, the stray inductances and capacitances can be reduced which further leads to a reduced base load which helps to reduce total energy consumption of the circuit.