AC Relay Module Circuit for Stable Switching Thresholds
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Solution Overview
Problem
Conventional relay modules suffer from wide response and dropout voltage ranges due to interference voltages and currents, leading to unintentional switching and misleading status indicators, especially in systems with long cable lengths and separate AC networks.
Innovation Solution
A relay module with a fixed voltage regulator, comparator, and switching stage that uses a derived reference voltage for state-independent switching, reducing hysteresis and eliminating the need for a separate power supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a low-pass filter is used to suppress AC network interference, then interference suppression is improved, but the switching threshold becomes unstable and hysteresis increases
Solution Approach 1:
The patent introduces an intermediary circuit between the AC control voltage input and the relay coil that actively processes the control signal. This intermediary circuit includes rectification, voltage regulation, and comparison stages that mediate the control signal to eliminate interference while maintaining stable switching threshold, resolving the contradiction between interference suppression and threshold stability.
2Use of energy by moving object
If the relay module is fed directly from AC voltage, then power consumption is reduced, but switching precision deteriorates due to wide response and dropout voltage ranges
Solution Approach 1:
The patent changes the electrical parameters of the control circuit by introducing rectification and voltage regulation stages. The AC control voltage is converted to DC through rectification, then regulated to a stable voltage level, and finally compared against a reference voltage. This parameter transformation enables precise switching control while maintaining low power consumption by operating from the AC control input without requiring additional power supply.
3Object-affected harmful factors
If a filter is connected in parallel to the input to limit unwanted characteristics, then interference limitation is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into a single integrated control circuit. The rectification, voltage regulation, and switching control functions are combined in one circuit path that processes the AC control voltage directly. This unified approach achieves interference limitation without requiring separate parallel filter circuits, thereby limiting complexity increase while maintaining effective interference suppression.
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 solution ensures precise and reliable switching with low hysteresis, preventing unwanted switching and incorrect status indications, while maintaining low power consumption and compact design.
Implementation Method 1
a fixed voltage regulator configured to generate a fixed voltage after rectification of the AC voltage or a portion of the AC voltage
Implementation Method 2
a comparator configured to be driven by the fixed voltage and to compare a reference voltage derived from the fixed voltage to a rectified and smoothed portion of the AC voltage
Data Source
AI summary
The present disclosure relates to a relay module including a control input for combined control and power supply of the relay module with alternating voltage. A fixed voltage controller of the relay module generates a fixed voltage after rectification of the alternating voltage or a portion of the alternating voltage. A comparator is operated by the fixed voltage and derives a reference voltage from the fixed voltage. The comparator compares a rectified and smoothed portion of the alternating voltage with the reference voltage. A switching step of the relay module operates a relay unit according to the comparison of the comparator, which relay unit is connected on the input side to the switching step and on the output side to switch connections of the relay module.