Induction Sealing Circuit Layout for Faster Impedance Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing impedance matching circuits in induction sealing devices for pourable food product packaging suffer from electromagnetic compatibility issues, high power dissipation, and sluggish switching due to complex architecture and separate electronic boards, leading to inefficiencies in power transfer and production.
Innovation Solution
A revised impedance matching circuit design with grounded input terminals, reduced number of power transistors, and optimized capacitor configurations allows for reduced electromagnetic emissions, lower heat dissipation, and faster switching, enabling more efficient power transfer and packaging production by eliminating phase shifts between voltage and current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a complex impedance matching circuit with separate electronic boards is used, then power transfer optimization is achieved, but electromagnetic compatibility deteriorates and device complexity increases
Solution Approach 1:
The patent combines the impedance matching circuit and control stage into a single integrated electronic board, eliminating separate boards and reducing electromagnetic interference while maintaining power transfer optimization capabilities
Solution Approach 2:
The patent introduces a grounded input terminal configuration as an intermediary structure that provides electromagnetic shielding and reference potential, reducing electromagnetic compatibility issues while enabling effective impedance matching
2Power
If multiple power transistors are used in the impedance matching circuit, then power transfer control is improved, but power dissipation increases
Solution Approach 1:
The patent extracts and eliminates redundant power transistors from the circuit, retaining only the essential number needed for impedance matching while removing those that contribute to excessive power dissipation
Solution Approach 2:
The patent optimizes the electrical parameters of remaining power transistors including their positioning relative to grounded terminals and their electrical characteristics to minimize on-resistance and reduce power dissipation while maintaining adequate power transfer control
3Use of energy by moving object
If a complex impedance matching circuit architecture is used, then power transfer optimization is achieved, but switching speed deteriorates
Solution Approach 1:
The patent segments the impedance matching circuit into distinct functional modules with independent switching control, allowing faster individual switching operations and reducing overall circuit switching delays
Solution Approach 2:
The patent positions power transistors and capacitors in predetermined optimal locations on the electronic board during manufacturing, pre-configuring the circuit for minimal switching path lengths and fastest possible switching speeds
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 revised circuit enhances electromagnetic compatibility, reduces heat dissipation, and improves switching speed, resulting in more efficient power transfer and packaging production with reduced electromagnetic interference and increased productivity.
Implementation Method 1
the inductor generates a pulsating magnetic field, which in turn produces parasitic electric current in the aluminium sheet in the packaging material from which the vertical tube is made, thus locally melting the heat-seal plastic cover material
Implementation Method 2
the impedance matching circuit is configured to eliminate or minimize the phase shift (angle), induced by the reactive impedance of the inductor, between the voltage and current supplied by the signal source, and so minimize the reactive power supplied by the signal source, and maximize the active power
Data Source
Figure 1
Figure 2~4
Figure 3
AI summary
An induction sealing device (10) for use to produce packages (7) of pourable food products from a tube (2) of heat-seal sheet packaging material (3). The sealing device (10) has a signal source (12) supplying an alternating power signal (S((ω)); an inductor (13) receiving the alternating power signal (S(ω)), and operable to induce electric current in the packaging material (3) to heat seal the packaging material (3); and an impedance matching circuit (11') connected between the signal source (12) and the inductor (13). The impedance matching circuit (11') has a pair of input terminals (11.1, 11.2) receiving the alternating power signal; a first (23) and second (24) line connected to the input terminals (11.1, 11.2); a variable-capacitance stage (21) having a number of capacitive modules (21.1-21.4) parallel-connected between the first and second line (23, 24), and each made up of a capacitive element (C1-C4) and a controlled switch (SW1-SW4) connected in series, each controlled switch (SW1-SW4) being selectively operable to connect the respective capacitive element (C1-C4) between the first and second line (23, 24); and a control stage (22) configured to control the operating statuses of the controlled switches (SW1-SW4) . Each controlled switch (SW1-SW4) has a pair of input terminals (SWa, SWb) receiving a respective control signal from the control stage (22), wherein one (SWb) of the input terminals (SWa, SWb) of each controlled switch (SW1-SW4) is connected to the second line (24); and a single two-way controlled switching element (IGBT) having a control terminal connected to the other input terminal (SWb) of the controlled switch (SW1-SW4), a first current-conducting terminal connected to the first line (23) via the respective capacitive element (C1-C4), and a second current-conducting terminal connected to the second line (24).