Relay Driver Circuit Buffer for Voltage Drop Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing relay driver circuits fail to maintain the operating state of a lower stage relay when a power supply voltage drop occurs due to the voltage drop caused by protective components in the control input line, leading to potential loss of control for semiconductor components driving inductive loads.
Innovation Solution
A relay driver circuit configuration that includes a semiconductor component, a control input line with a protective component, and a buffer circuit comprising a PNP and NPN bipolar transistor to compensate for the voltage drop, ensuring the lower stage relay remains operational even during power supply voltage drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective component is connected in the control input line to protect the semiconductor component, then the semiconductor component is protected from surge, but the control input voltage drops due to voltage drop of the protective component
Solution Approach 1:
A buffer circuit is introduced as an intermediary between the protective component and the semiconductor component. The buffer circuit receives the control signal after it passes through the protective component and reconstructs the control input voltage, compensating for the voltage drop caused by the protective component. This allows the protective component to remain in the control input line for surge protection while maintaining sufficient control voltage for reliable semiconductor component operation.
2Loss of energy
If power supply voltage drops, then power consumption is reduced, but the semiconductor component cannot remain in on state and relay operating state is not maintained
Solution Approach 1:
The buffer circuit is configured to activate and compensate for voltage drops before the semiconductor component's control voltage falls below the threshold required to maintain the on state. By proactively reconstructing the control input voltage through the buffer circuit when power supply voltage begins to drop, the system maintains reliable relay operation through the entire voltage drop event without losing the on state.
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
The buffer circuit effectively reduces voltage drops, maintaining the operating state of the lower stage relay by applying a power supply voltage with minimal loss, thus enhancing the reliability and safety of systems like vehicle power systems.
Implementation Method 1
The buffer circuit is connected between the protective component in the control input line and the control terminal of the semiconductor component to compensate for a voltage drop due to the protective component
Data Source
AI summary
A relay driver circuit is connected between an upper stage relay and a lower stage relay and is configured to be driven in response to driving of the upper relay. The relay driver circuit drives the lower stage relay. The relay driver circuit includes a semiconductor component, a control input line, a protective component, and a buffer circuit. The semiconductor component switches on and off the lower relay. The control input line is electrically connected to a control terminal of the semiconductor component. A power supply voltage is applied to the control input line via the upper stage relay. The protective component is connected in the control input line to protect the semiconductor component. The buffer circuit is connected between the protective component in the control input line and the control terminal of the semiconductor component to compensate for a voltage drop due to the protective component.