The transmitting and driving of ultrasonic transducer is quite simple, and the driving voltage is not higher than the rated voltage of transducer. Considering the mechanical fatigue of materials, it is generally not recommended to use too high drive. For the transducer, within the rated voltage range, the higher the voltage is, the stronger the output sound pressure is, and the farther the distance can be measured. Now let's talk about the content of the transmitter.

During ultrasonic emission, people often ask matching questions. Generally speaking, the matching is two: one is the matching of transformer and transducer. The second is to add inductance and the capacitance of the transducer to match.

The impedance of the transducer is generally large, ranging from a few hundred Ohms to a few K Ohms. So the output of the transformer is easy to match. Moreover, the ranging transducer is driven by pulse, so the requirements for transformer are generally not high. The number of turns of the transformer depends on the input voltage at the primary level. Generally, the voltage of 1V corresponds to 0.8 turns. The number of turns can be 10-15 times.

The transducer is a capacitive load. If no inductance is added for matching, there will be some dielectric loss. However, because the bandwidth of rangefinder transducer is generally wide, the author does not recommend using inductance for matching, so that your circuit can directly use transducers of different frequencies. If it is a single frequency product, and the Q value of the transducer is relatively high.