Ultrasonic power supply is divided into self-excited power supply and other-excited power supply according to design.
The self-excited circuit has no signal source. It integrates the oscillation, power amplifier, output transformer and transducer into a closed loop, and the loop meets the amplitude and phase feedback conditions to form an oscillator with power amplification. And resonate at the mechanical resonance frequency of the transducer. It is generally used for small equipment with a small number of ultrasonic transducers; however, for a large number of ultrasonic transducers, it is impossible to debug to achieve the resonance effect. Therefore, most of the current ultrasonic power supply for industrial ultrasonic cleaning equipment adopts other exciting methods.
The structure of his excited power supply mainly includes two parts, the pre-stage is an oscillator and the post-stage is an amplifier. Generally through the output transformer coupling, the ultrasonic energy is added to the transducer. The circuit of the exciting mode is composed of two parts, namely the signal source part and the signal amplifying part.
The signal source part uses the CPU as the core signal generation and control part. Generally, it is driven by 12-15V voltage to generate a square wave signal for the signal amplification circuit; the timing control and adjustment of the ultrasonic power supply and other additional functions can pass the signal of the control signal source. The output mode is completed, low voltage control is adopted, and the safety and reliability will be definitely high.
The signal amplification part amplifies the signal generated by the signal source and outputs it to the ultrasonic transducer. The difference in the output circuit and voltage of the ultrasonic power supply of different circuits is an important reason for the propagation efficiency. The output voltage is low, the generator consumes a lot of energy, and the vibrator is also easy to heat, and the induced electric field is strong. Proper adjustment of the circuit to increase the voltage output to the ultrasonic transducer may achieve good results.
