Constant Current Thread Break Indicator Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing yarn feeding devices for knitting machines face challenges in providing a clear and unmistakable signal for thread breakage across different machine systems, especially when porting devices between machines, and require a solution that is compatible with previous signaling devices and can operate independently of voltage fluctuations.
Innovation Solution
A signaling device connected to the yarn feeder's clamp, featuring a current source circuit that supplies constant current to light sources within a predetermined voltage range, allowing for reliable detection of thread breakage and versatility across different voltage types, including DC and AC, with a rectifier circuit and switches to activate light sources only when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a constant voltage circuit is used to operate light sources, then the signaling device can operate with different voltage supplies, but the current drawn from the feed circuit varies with voltage fluctuations, reducing detection reliability
Solution Approach 1:
The patent transforms the electrical circuit from a constant voltage operation mode to a constant current operation mode. The current source circuit maintains a predetermined constant current regardless of voltage fluctuations in the feed circuit, ensuring reliable detection. This parameter change from voltage-based to current-based operation resolves the contradiction by making the detection signal independent of voltage variations while maintaining compatibility with different voltage supplies.
2Reliability
If light sources are continuously powered, then the signaling is always ready, but energy is wasted when no thread breakage occurs
Solution Approach 1:
The patent implements periodic action by using switches that activate the light sources only when thread breakage is detected. The thread feeler lever periodically checks the thread status, and only when a breakage occurs does the circuit activate to illuminate the light sources. This eliminates continuous energy consumption while maintaining reliable detection capability, as the system is ready to signal immediately upon breakage detection.
3Reliability
If multiple yarn feeding devices are connected in parallel to detect thread breakage, then comprehensive monitoring is achieved, but cable resistance and contact resistance affect the accuracy of detection
Solution Approach 1:
The patent replaces the traditional voltage-based electrical system with a current-based system. By using a current source circuit that supplies constant current to each light source, the system becomes independent of cable resistance and contact resistance variations. The constant current ensures that the brightness of the light sources accurately reflects the number of active detection points without being affected by electrical resistance in the connecting cables.
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 signaling device provides a clear and reliable indication of thread breakage, allowing for accurate detection of multiple yarn feeding devices and operating across a wide voltage range, reducing internal losses and enhancing compatibility with various machine systems.
Implementation Method 1
a current source circuit (33) for operating one or more light sources (36) for display purposes
Implementation Method 2
The current source circuit is preferably combined with a rectifier circuit. The yarn feeding device can then be operated equally well with DC and AC voltage
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A signalling circuit which uses a constant current source to operate one or more light sources (36) is proposed as signalling device (23) for a thread delivery device (1). This firstly makes its use possible in the case of fluctuating or differently stipulated operating voltages, and secondly makes it possible to detect the number of responding thread delivery devices (1) via the central supply circuit.