Ultrasonic power generators , also known as ultrasonic drive power supplies, electronic boxes, and ultrasonic controllers, are important components of high-power ultrasound systems. The function of the ultrasonic generator is to convert the commercial power into a high-frequency alternating current signal matched with the ultrasonic transducer to drive the ultrasonic transducer to work. The high-power ultrasonic power supply generally adopts the circuit form of the switching power supply in terms of conversion efficiency. Ultrasonic power supplies are divided into self-excited and its excited power supplies. Self-excited power supplies are called ultrasonic analog power supplies. They are both power supplies and ultrasonic power generators.
The ultrasonic power generator adopts the world's leading structure of the oscillating circuit, which increases the output power by more than 10% compared with the self-excited oscillating circuit structure. The ultrasonic amplifying circuit adopts a linear amplifying circuit and a switching power supply circuit.
Advantages of the switching power supply circuit: The conversion efficiency is high, so the high-power ultrasonic power supply adopts this form.
Advantages of linear power circuits: Circuit matching is not strictly required, allowing the operating frequency to change continuously and rapidly.
The ultrasonic power generator generates a signal of a specific frequency, which may be a sinusoidal signal or a pulsed signal. This specific frequency is the frequency at which the transducer operates.
Ultrasonic equipment generally uses ultrasonic waves of 20 kHz, 25 kHz, 28 kHz, 33 kHz, 40 kHz, 60 kHz, 80 kHz, 100 kHz or more, and has not been used in large quantities.
How to feedback the signal:
The perfect ultrasonic power generator has a feedback link, which mainly provides feedback signals in the following two aspects.
1, output power
When the ultrasonic generator input voltage changes, the output power of the generator also changes. The mechanical vibration of the ultrasonic transducer is unstable, resulting in poor working results. Therefore, it is necessary to stabilize the output power, and the power amplifier is adjusted correspondingly by the power feedback signal, so that the power amplification is stable.
2, frequency tracking
The transducer operates at the resonant frequency point with the highest efficiency and the most stable operation.
The resonant frequency point of the transducer changes due to assembly and aging. If the changed frequency is only drifting, the change is not large, the frequency tracking signal can control the signal generator, so that the frequency of the signal generator tracks the resonant frequency point of the transducer within a certain range, so that the generator works at an optimal state.