High-Frequency Transducers: Applications and Design
High-frequency transducers, characterized by frequencies of 20 MHz and beyond, are single-element contact or immersion transducers. Contact transducers are available with frequencies reaching up to 225 MHz. The performance of these transducers is intricately tied to the pulse, receiver, and specific application requirements.
Frequency Probes for Imaging: Tailoring Depth and Resolution
Frequency probe play a crucial role in imaging small, superficial structures at shallow depths, emphasizing high resolution. For imaging at greater depths, the utilization of powerful low-frequency probes becomes essential, marking a significant parameter dependence on the depth of the imaging.
Utilizing Frequency Probe for Digital Circuit Monitoring
The frequency probe serves the dual purpose of ”listening in” to the speed of a computer and is equally compatible with other digital circuits. Its ability to render high-frequency signals audible facilitates convenient signal monitoring. The inclusion of a 12-bit counter as a frequency detector ensures precise measurement. The signal, divided by 1024, is output at pin 14, subsequently controlling transistor T1. Which, in turn, drives the piezo buzzer Bz1.
Scale Factor Selection for Frequency Monitoring
The chosen scale factor is designed to convert MHz into KHz, ensuring that the clock frequency of, for instance, an XT computer translates into a distinct 8 kHz tone. Adjusting for higher frequencies necessitates obtaining scale factors of 2048 and 4096 by connecting R2 to pin 15 or pin, respectively. When utilizing an HCT circuit, the measuring limit extends to several tens of MHz. For frequencies below 4 MHz, a standard Type 4040 may suffice, offering the advantage that the supply voltage doesn’t need to precisely match 5 V. Optimal connections for the supply and probe involve flexible wires terminated with crocodile clips.
Monitoring Higher Frequencies: Scale Factor Adaptation
For effective monitoring of higher frequencies, the scale factor can be adjusted by connecting R2 to pin 15 or pin, yielding scale factors of 2048 and 4096, respectively. When employing an HCT circuit, the measurement capability extends to several tens of MHz. Alternatively, for frequencies below 4 MHz, a standard Type 4040 proves sufficient, presenting the advantage of not requiring an exact 5 V supply voltage. The recommended approach for optimal connections involves flexible wires terminated with crocodile clips for both the supply connections and the probe.