Ultrasonic Generator Phase Control for Resonance
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Solution Overview
Problem
Existing ultrasonic generators for welding and cleaning struggle to operate at a predetermined output power and vibration amplitude in a simple and cost-effective manner, as they require complex frequency regulation to maintain resonance states.
Innovation Solution
The method involves determining the phase difference between current and voltage in the oscillating circuit of the ultrasonic generator, using this phase difference to control the excitation frequency to reach resonance points, allowing for efficient operation between parallel and series resonances, thereby simplifying the regulation of output power and vibration amplitude.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If complex frequency regulation is used to maintain resonance states, then the precision of maintaining predetermined output power and vibration amplitude is improved, but the device complexity increases
Solution Approach 1:
The patent changes the control parameter from complex multi-variable frequency regulation to simple phase difference control. By monitoring the phase difference between current and voltage and adjusting the excitation frequency based solely on this phase difference parameter, the system achieves precise resonance maintenance without complex regulation mechanisms. The phase difference serves as a direct indicator of resonance state, enabling simplified control while maintaining high precision output power and vibration amplitude control.
2Reliability
If complex frequency regulation systems are implemented, then the reliability of maintaining resonance is improved, but the cost increases
Solution Approach 1:
The system uses the inherent electrical characteristics (phase difference between current and voltage) of the ultrasonic transducer itself as the control signal. The phase difference naturally indicates when resonance is achieved, eliminating the need for external sensors or complex feedback systems. This self-service approach maintains high reliability of resonance maintenance while significantly reducing manufacturing costs by using readily available electrical measurements instead of expensive additional components.
3Loss of time
If operation continues above parallel resonance frequency, then the response time for frequency adjustment is improved, but harmful secondary resonances occur
Solution Approach 1:
The system continuously monitors the phase difference between current and voltage as feedback and uses this information to automatically adjust the excitation frequency. When the phase difference indicates approaching resonance (reaching 0°), the system stops increasing frequency, preventing overshoot into harmful secondary resonance regions. This feedback mechanism enables rapid frequency adjustment while automatically preventing the generation of harmful secondary resonances by stopping frequency increase at the optimal point.
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
This approach allows for more straightforward and cost-effective control of ultrasonic generators, achieving high power output with lower voltage requirements and optimizing vibration amplitudes by regulating the frequency within a defined frequency band, avoiding unnecessary secondary resonances.
Implementation Method 1
the phase difference between current and voltage of an excitation signal in the resonant circuit is determined at least when the oscillating system is started up with an initial excitation frequency and is used for frequency control of the ultrasonic generator
Implementation Method 2
at least one electro-mechanical oscillating system of the ultrasonic transducer
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The method involves connecting a resonant circuit (2e) with an electro-mechanical oscillating system of an ultrasonic transducer (3). The initial excitation frequency of the resonant circuit is determined. The phase difference between current and voltage of excitation signal is detected for the frequency control of an ultrasonic generator. The oscillating system is excited at initial frequency to ultrasonic vibrations. The excitation frequency of the oscillating system is controlled such that the phase of impedance of oscillating system is set to preset range. Independent claims are included for the following: (1) an ultrasonic generator; and (2) an ultrasonic system with ultrasonic generator.