Contact System With Magnet For Balanced Voltage Drop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing contact systems, such as relays and contactors, face challenges in maintaining balanced contact pressure across normally open and normally closed contacts, leading to de-rating and unequal voltage drop values, which can result in higher voltage drops at normally closed contacts and require de-rating to maintain acceptable limits.
Innovation Solution
Incorporating a magnet that provides additional magnetic force to complement the coil's magnetic field, allowing the return spring to be designed with a stronger pre-load, ensuring balanced forces are applied to both normally open and normally closed contacts, thus eliminating de-rating and achieving identical contact voltage drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a return spring is used to maintain contact pressure at normally closed contacts, then contact pressure is maintained, but the spring force must be weaker resulting in de-rating of normally closed contacts
Solution Approach 1:
The patent combines the functions of the return spring and the coil assembly into a unified force system. The coil assembly serves dual purposes: actuating the contacts and providing additional downward force to supplement the return spring, thereby maintaining full contact pressure at normally closed contacts without requiring a weaker spring design.
Solution Approach 2:
The coil assembly is designed to perform multiple functions: it actuates the movable contact to switch circuits and simultaneously provides supplemental force to maintain contact pressure at normally closed contacts. This multi-functionality eliminates the need to compromise spring pre-load for proper pickup and dropout operation.
2Ease of operation
If the return spring is designed with weaker pre-load for proper pickup and dropout, then switching operation is maintained, but contact force at normally closed contacts is reduced
Solution Approach 1:
The patent merges the actuation function and the contact pressure maintenance function into a single coil assembly system. The coil provides both the force needed for proper pickup and dropout operation and the additional downward force required to maintain full contact pressure at normally closed contacts during operation.
3Force
If a larger coil is used to achieve sufficient force on contact transfer, then contact force is improved, but size and cost of the switch increase
Solution Approach 1:
The coil assembly is designed to perform multiple functions with a single component: it actuates the contacts for switching operation and simultaneously provides supplemental force to maintain contact pressure. This eliminates the need for a larger, more expensive coil that would be required if the return spring alone had to provide all necessary forces.
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 solution ensures balanced contact forces and voltage drops across both normally open and normally closed contacts, eliminating the need for de-rating and maintaining reliable operation within specified parameters, resulting in a full-rated switch or relay.
Implementation Method 1
A coil assembly which, when energized generates a force which attracts the at least one movable contact to the at least one first contact
Implementation Method 2
A magnet having a magnetic force which attracts the at least one movable contact to the at least one first contact
Implementation Method 3
A return spring having a spring force cooperates with the at least one movable contact to return the at least one movable contact to the at least one second contact when the coil is not energized
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A contact system includes at least one first contact (4), at least one second contact (1), and at least one movable contact (3). A coil (12) is provided which, when energized generates a force. A magnet (9) is also provided, the magnet (9) having a magnetic force. The forces of the coil (12) and magnet (9) attract the at least one movable contact (3) to the at least one first contact (4). A return spring (8) having a spring force cooperates with the at least one movable contact (3) to return the at least one movable contact (3) to the at least one second contact (1) when the coil (12) is not energized. The sum of the forces applied by the coil (12) and the magnet (9) are sufficient to overcome the spring force of the return spring (8) to provide a balanced force to both the at least one second contact (1) and the at least one first contact (4).