Avatar Image Laboratory Device Of Ultrasonic Graphene Dispersion
rawrubber

The consideration when using an ultrasonic transducer is the matching with the input and output ends

The main consideration when using an ultrasonic transducer is the matching with the input and output ends, followed by mechanical installation and matching dimensions. The frequency of the transducer is relatively intuitive. The frequency refers to the frequency measured by the transmission line method with a frequency (function) generator, millivoltmeter, oscilloscope, etc., or the frequency measured with a similar instrument such as a network impedance analyzer. Generally referred to as small signal frequency. Corresponding to it is the computer frequency, that is, the actual operating frequency measured when the customer connects the transducer to the chassis through a cable and is powered on without load or with a load. Because the matching circuits of customers are different, the frequency of the same transducer in different driving power sources (electric boxes) is different, and this frequency cannot be used as a basis for exchange discussions.

Let the transducer, the driving power supply and the mold cooperate well to form a complete ultrasonic equipment can be referred to as matching for short. Since the impact of matching on the performance of the whole machine is decisive, no matter how the importance of matching is emphasized, it cannot be overstated. The main consideration for matching is the capacitance of the transducer, followed by the frequency of the transducer.

The matching of the transducer and the driving power supply mainly has 4 aspects, namely impedance matching, frequency matching, power matching and capacitive reactance matching. The most important ones are capacitive reactance and frequency. As mentioned earlier, because the ceramic sheet is an insulator, you can almost understand that the transducer is not energized, it is just equivalent to a capacitor. To make the transducer work, it is actually to apply a high AC voltage to it through the drive circuit to charge and discharge the capacitance of the transducer. The piezoelectric ceramic sheet undergoes synchronous expansion and contraction under the action of an alternating electric field, forming the longitudinal vibration of the entire transducer, thereby driving the vibration of the horn and the mold. Therefore, if the capacitor matching is not good, the lighter is the weak transducer and the welding is not firm; the heavy one, the transducer heats up seriously, burning the electrodes and the high-power tube of the power supply. Our transducer products are accompanied by a product performance parameter table, which shows the capacitance and frequency of each transducer. The driving power supply should adjust the parameters of the high-voltage transformer, matching capacitor plate, peaking coil, and frequency modulation coil according to the capacitance of the transducer. Due to the sensitivity of inductance and capacitance, power amplifier boards, choke coils and other peripheral circuits also affect the matching. Moreover, as the work progresses, the temperature of the transducer will rise, resulting in an increase in capacitance and the change may exceed 50%. If the capacitance cannot be effectively matched, it will cause a large current and voltage phase difference in the loop , The power factor is very low and the virtual work is high. Look at the high current, but the transducer is weak, easy to heat, and the power device of the power supply is also easy to heat and damage. Generally, the transducer electrode (ear) cracks or burns out is probably caused by this.

Tags:

Leave a Reply