Differential Signal Coupler for Ground Offset Interference Rejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing signal transmission methods between gate drivers with different ground potentials in electric motors face challenges due to ground offsets and induced voltages, leading to interference and potential isolation requirements, which are costly and complex.
Innovation Solution
A coupler system using differential transmission with a filter arrangement and amplifiers to overcome ground offsets, employing common-mode chokes and RC filters to suppress interference, and polarity reversal protection to safeguard components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If potential-isolating transformers are used to overcome ground offset, then signal transmission reliability is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces a coupler as an intermediary device between transmitter and receiver. This coupler contains a filter arrangement that separates common-mode interference from differential signals, allowing signal transmission without requiring potential-isolating transformers. The coupler acts as a mediator that enables reliable communication across ground offsets while maintaining circuit simplicity.
Solution Approach 2:
The patent extracts and removes the common-mode interference component from the signal transmission path using the filter arrangement. By separating and eliminating the harmful common-mode signals while preserving the differential signal components, the system achieves reliable transmission without the complexity of isolating transformers.
2Object-affected harmful factors
If RC filter circuit is used to suppress interference, then interference suppression is improved, but signal transmission speed deteriorates
Solution Approach 1:
The patent segments the signal into differential components and common-mode components. The filter arrangement specifically targets and filters only the common-mode interference while leaving the differential signal components unaffected. This selective filtering approach allows for aggressive interference suppression without compromising signal transmission speed, as the useful differential signals pass through without being slowed by RC time constants.
3Object-affected harmful factors
If common-mode interference is filtered using traditional filters, then interference suppression is improved, but device complexity and time constant increase
Solution Approach 1:
The coupler serves as an intermediary that implements a relatively simple filter arrangement to remove common-mode interference. This filter arrangement may include basic RC filters or common-mode chokes, which are less complex than traditional approaches. The coupler architecture enables effective common-mode rejection while maintaining simplicity in the filtering components themselves.
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
Enables reliable and rapid signal transmission across ground offsets, reducing component costs and complexity while maintaining signal integrity, particularly in fault conditions.
Implementation Method 1
the components of the signal that are transmitted via the two signal lines are guided onto magnet coils that are wound in opposite directions such that the magnetic fields of the common-mode interference contained in the two signal components cancel one another out and the common-mode interference is therefore inductively attenuated
Implementation Method 2
A large amount of the common-mode interference is already removed by the calculation in the comparator subtracting the components of the signal that are transmitted via the two signal lines from one another
Data Source
AI summary
The invention relates to a coupler (1) for differential transmission of an analogue signal (3) coming from at least one transmitter (2) with a first earth potential (2a), via at least one first signal line (4a) and a second signal line (4b), to a receiver (5) with a second earth potential (5a), wherein the coupler (1) has a filter assembly (6) for the portions (3a, 3b) of the signal (3) being transmitted via the first signal line (4a) or via the second signal line (4b), wherein this filter assembly (6) is potential-free or uses the second earth potential (5a), and wherein the portions (3a′, 3b′) of the signal (3) filtered by the filter assembly (6) are brought together in a comparator (7) in order to form the signal (8) to be supplied to the receiver (5), and wherein the comparator (7) uses the second earth potential (5a). The invention also relates to a system (50) for signal transmission and a voltage transformer (100) comprising the coupler (1) and/or system (50).