Product Design Principles
The ultrasonic cleaning transducer usually adopts horn-type composite oscillator structure (belonging to Langevin oscillator structure), which consists of front and rear metal cover, piezoelectric ceramic chips, pre-stressed screw, electrode slice, and insulating sleeve. Imposed by appropriate pre-stress, the transducer has good mechanical and electrical conversion efficiency under high power and large-amplitude conditions.
It is through the ultrasonic vibration-wave of the transducer occurring cavitations in the water and generates high-pressure vacuole to impact the cleaning materials, so as to achieve an excellent cleaning effect.
The ultrasonic cleaning transducer is a medium-power transducer that can work continuously. Generally, the power value is calculated according to the average of continuous and constant work.
Frequently Asked Questions
Q: How to judge positive and negative electrodes of the transducers?
A. The electrode located between the two piezoelectric chips is positive.
Q: The insulation method of the transducer?
A: Parallel connection; pull the wire through the hole and need to be welded with tin; make sure to avoid lap welding.
Q: How to opt suitable wires that connected to the transducer?
A: Adopt soft enough silicone wire, around 1.2 square diameters.
Q: How to insulation method of the transducer.
A: Exposed wires and soldered positions need to be sealed with heat-shrinkable tube and silicone glue.
Q: How to test the insulation of the transducer?
A: Use a megohm meter around 1500V to test the insulation impedance of the positive and negative electrodes; required greater than 50MΩ, except for high humidity environments.
Q: What’s the meaning of the parameters of transducer?
A: Free capacitance CT=C0+C1，”C0” refer to the static capacitance, “C1” for the dynamic capacitance; “Dt” for the dielectric loss; “fs” for the series resonant frequency, “fp” for parallel resonant frequency and the frequency bandwidth “fsp” = fp-fs; bandwidth “f12” = f2-f1, “f1” and “f2” respectively corresponding to the left and right point of the half-power bandwidth; “R1” refers to the dynamic impedance; “L1” for the dynamic inductance; “Zr” or “Zmin” for the parallel resonant impedance; “Zmax” for the series resonant impedance; “Qm” for the mechanical quality factor; “Keff” for the coupling coefficient.
Q: Transducers are grouped as per what order of parameter?
A: Transducers of our company are classified as per the order of frequency, capacitance and then impedance.
Q: What’s the definition of the power of transducer?
A: Ultrasonic cleaning transducer is generally rated average power. It’s defined as the maximum input power upon resonant frequency.
Q: What’s the definition of the power of washing machine?
A: Washing machine power, usually defined as the geometric product of the transducer numbers with rated power, which is known as the nominal power. But the input electric power is less than nominal power.
Q: Why the input electric power is lower than the power of the washing machine?
A: A single transducer power is the maximum power upon resonant frequency. Once a number of transducers are in parallel, the total frequency may deviate from the resonance frequency of a single transducer due to the consistency and adhesive techniques of the transducer. It means that the transducers can’t work under the best frequency, so the total input electric power is lower than the nominal power of the washing machine. The more transducers are in parallel, the greater deviation between the two powers.
Q: Option of the power of the washing machine.
A: The power of washing machine is determined by the size of cleaning container and arrangement of transducers, usually calculated according to the power density 0.5-0.6w/cm2.
Q: How to arrange the transducers for the washing machine?
A: Transducer-arrangement depends on the structure of cleaning container and the effective distance of different frequency, and then substitutes the power-density into formula to calculate the number and get an integer.
Q: Why there are multiple frequencies when debug the machine?
A: When the transducer is being debugged, there’re four frequencies around the resonance point under a strong electric field. The lower one is the lateral vibration-frequency of oscillator, followed is the overall frequency of the oscillator and bonded stainless steel in the vibration direction, which is lower than the natural frequency of the transducer; the third is the natural frequency of the transducer and the fourth is the vibration frequency in the diameter direction of the piezoelectric-ceramic chips. The second and third frequencies are available. In addition, if the inductance of the circuit matches poor, the deviated frequency may induce vibration.
Q: What’s the advantage of the sweep-frequency circuit?
A: Sweep-frequency circuit allows each oscillator in parallel to have an opportunity of best frequency in a single pulse period. It reduces the requirements of the installation techniques and the consistency of ultrasonic. In addition, the ultrasonic vibration has a better impact and ultrasound uniformity than the continuous circuit upon operating and its input electric power is lower and more reliable.
