Solid-State Switch Parallel Relay Arcing Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Relays used in control switches for inductive loads face high initial current draw issues, leading to contact burning and reduced reliability, and latching relays are expensive and unreliable for maintaining contact states.
Innovation Solution
A switching means comprising a solid-state switch in parallel with a normally closed relay, where the solid-state switch is activated to conduct before the relay, and then de-activated to prevent arcing, with a micro-controller managing the switching sequence and a flyback converter charging a capacitor to maintain relay contact opening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a relay is used to connect inductive loads, then the control circuit can switch higher voltage supplies, but high initial current draw causes contact burning and reduces reliability
Solution Approach 1:
The solid state switch is activated before the relay contacts close to establish a low-impedance path for inductive current. This preliminary action allows the relay to switch without承受 the full inductive current burden, preventing contact burning and extending relay lifespan while maintaining the ability to control high power loads
2Duration of action of moving object
If relay contacts are held closed for substantial time, then the load remains connected, but continuous power is required to energize the relay
Solution Approach 1:
A capacitor is pre-charged through a flyback converter during the period when power is available (when load is connected). This stored energy in the capacitor is then used to maintain the relay energized state during the period when power is diverted to the load, eliminating the need for continuous power consumption from the mains supply
3Use of energy by moving object
If latching relays are used to reduce power consumption, then continuous power supply is not required, but they are expensive and unreliable
Solution Approach 1:
A capacitor serves as an energy intermediary, storing power when available and releasing it when needed. This mediator approach replaces the unreliable latching relay mechanism with a simple capacitive energy storage system that reliably maintains the relay energized state without requiring expensive or complex latching mechanisms
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 arcing and overheating of relay contacts, extends relay lifespan, and conserves energy by using the solid-state switch to manage high initial currents and maintain contact states efficiently.
Implementation Method 1
a solid-state switch arranged in parallel with a relay of normally closed type, the solid-state switch and the relay being arranged in series with the load and the power supply
Implementation Method 2
a flyback converter charging a capacitor to maintain relay contact opening
Implementation Method 3
the control switch includes a switching capacitor that is used to provide power for opening the contacts of the relay
Implementation Method 4
the control switch comprises a solid-state switch arranged in parallel with a relay of normally closed type
Data Source
AI summary
A switching device for controlling the supply of power from a supply to a load comprises a solid-state switch arranged in parallel with a relay of normally closed type. The solid-state switch and the relay are arranged in series with the load and the power supply. The switch also comprises a control adapted to connect the power supply to the load by applying an activation signal to the solid-state switch to cause it to conduce, then de-energizing the relay and then removing the activation signal to the solid-state switch in that order. The control is also adapted to disconnect the power supply from the load by applying an activation signal to the solid-state switch to cause it to conduct, then energizing the relay and then removing activation signal to the solid-state switch in that order. A corresponding method of operation is also disclosed.