Integrated Engine Starter Circuit With Shared Solenoid and Braking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine starter circuits in the aerospace industry have unnecessary duplication of common circuits, leading to increased component count and board area, due to separate solenoid and braking circuits with high side and low side switches, which is inefficient and costly.
Innovation Solution
A combined solenoid and braking circuit using a common switch, shared inductor coil, and freewheeling diodes, with integrated built-in-test circuits to monitor and control current flow, reducing components and board space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate solenoid and braking circuits with high side and low side switches are used, then functional reliability is improved, but device complexity and board area increase
Solution Approach 1:
The patent combines the solenoid circuit and braking circuit into a single integrated circuit that shares a common high side switch. This merging reduces the total number of switches from four (two high side + two low side) to three (one common high side + two low side), thereby reducing device complexity and board area while maintaining the functional reliability of both solenoid and braking operations through shared control logic
2Reliability
If separate solenoid and braking circuits with duplicate components are used, then functional independence is improved, but manufacturing cost increases
Solution Approach 1:
The common high side switch is designed to serve dual functions: controlling both the solenoid circuit and the braking circuit. This universal component performs multiple roles that would traditionally require separate dedicated switches, thereby reducing the total component count and manufacturing cost while maintaining functional independence through software-controlled switching logic
3Reliability
If duplicate high side and low side switches are used for solenoid and braking circuits, then circuit functionality is improved, but board area increases
Solution Approach 1:
The patent merges the solenoid and braking circuits by eliminating redundant high side switches. The common high side switch replaces two separate high side switches, and the shared control logic replaces duplicate control circuitry, resulting in significant board area reduction while preserving all necessary circuit functionalities for both solenoid operation and braking operation
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
Reduces the number of components and board space, lowers costs, and enhances fault detection and control efficiency by integrating solenoid and braking circuits with a common switch, while maintaining functionality and safety.
Implementation Method 1
a brake resistor configured to provide a resistance to current generated by the electric machine flowing towards the electrical bus
Implementation Method 2
an inductor coil configured to provide current to the electric machine
Data Source
AI summary
In accordance with at least one aspect of this disclosure, an engine (e.g., an aircraft turbine engine) can include a turbine mounted to a turbine shaft to rotate the turbine. A starter system can include a starter circuit, for example for powering the starter system to start the engine. More specifically, the starter circuit can be configured to provide power to an electric machine (e.g., an electric motor capable of also acting as a generator) coupled to the turbine shaft to drive the engine.