Doppler Ultrasound Transmitter Circuit

The 2.25-MHz oscillator Q1 drives amplifier Q2 and XTAL1, an ultrasonic transducer. The transducer is a lead zirconate-titanate type. Taps on T1 and T2 provide low-impedance drive points.

The circuit consists of a 2.25-MHz oscillator (Q1) that serves as the primary frequency generator. This oscillator is crucial for producing the high-frequency signal required for the operation of the ultrasonic transducer, which in this case is a lead zirconate-titanate (PZT) type. PZT materials are known for their piezoelectric properties, allowing them to convert electrical energy into mechanical vibrations, which are essential for ultrasonic applications.

The output from the oscillator (Q1) is fed into amplifier Q2. The role of this amplifier is to strengthen the signal generated by the oscillator, ensuring that it is sufficiently powerful to drive the ultrasonic transducer effectively. This amplification is critical, as the transducer requires a certain level of input power to operate efficiently and produce the desired ultrasonic waves.

Additionally, the circuit includes taps on transformers T1 and T2, which are designed to provide low-impedance drive points. These taps facilitate the connection of the oscillator and amplifier to the transducer while minimizing losses and ensuring that the signal remains strong and stable. The low-impedance characteristic is particularly important in high-frequency applications, as it helps to reduce reflections and improve overall circuit performance.

In summary, this circuit configuration is optimized for ultrasonic applications, leveraging the properties of the lead zirconate-titanate transducer, while ensuring robust signal amplification and efficient power delivery through the use of low-impedance drive points. The 2.25-MHz.osciJlator Ql drives amplifier Q2 and XTAL1, an ultrasonic transducer. The transducer is a lead zireonate-titanate type. Taps on Tl and T2 provide low-impedance drive points. 🔗 External reference