directly-heated cathode

简明释义

直热式阴极

英英释义

例句

1.In high-frequency applications, a directly-heated cathode can reduce warm-up time.

在高频应用中，直接加热阴极可以减少预热时间。

2.A directly-heated cathode can operate at higher temperatures than indirectly heated ones.

直接加热阴极能够在比间接加热阴极更高的温度下工作。

3.Engineers prefer a directly-heated cathode for its efficient electron emission.

工程师们更喜欢使用直接加热阴极，因为它能有效发射电子。

4.The directly-heated cathode technology is widely used in radio transmitters.

直接加热阴极技术广泛应用于无线电发射器中。

5.The performance of the vacuum tube was significantly improved by using a directly-heated cathode.

通过使用直接加热阴极，真空管的性能显著提高。

作文

The field of electronics has witnessed numerous advancements, one of which is the development of the directly-heated cathode (直接加热阴极). This technology plays a crucial role in various applications, particularly in vacuum tubes and cathode ray tubes, which were once ubiquitous in televisions and radio devices. Understanding the function and significance of a directly-heated cathode is essential for anyone interested in the history and evolution of electronic components.A directly-heated cathode consists of a filament that is heated directly by an electric current. When the filament reaches a high temperature, it emits electrons through a process known as thermionic emission. This phenomenon occurs because the thermal energy provides enough energy to overcome the work function of the material, allowing electrons to escape from the surface of the cathode. The ability to generate a cloud of free electrons is fundamental for the operation of various electronic devices.One of the primary advantages of a directly-heated cathode is its efficiency. Since the cathode itself generates heat, there is no need for an additional heating element, which simplifies the design and reduces the overall size of the device. This efficiency is particularly beneficial in applications where space and power consumption are critical, such as in portable electronic devices.Moreover, directly-heated cathodes can achieve higher temperatures compared to indirectly heated cathodes, leading to improved electron emission and performance. This characteristic makes them ideal for high-power applications, such as in audio amplifiers and high-frequency oscillators, where maximizing electron flow is essential for achieving optimal performance.However, the use of directly-heated cathodes is not without its challenges. One significant issue is the need for precise control of the filament temperature to ensure consistent electron emission. If the temperature fluctuates, it can lead to instability in the output signal, which is undesirable in sensitive electronic applications. Additionally, the materials used for the filament must withstand high temperatures and have good electrical conductivity, making material selection a critical aspect of the design process.In recent years, advancements in materials science have led to the development of new filament materials that can operate at even higher temperatures while maintaining stability. These innovations have expanded the potential applications of directly-heated cathodes in modern electronics. For instance, they are increasingly being used in high-performance vacuum tubes that are favored by audiophiles for their warm sound quality, as well as in scientific instruments that require precise electron beams.The resurgence of interest in vacuum tube technology, particularly in audio equipment, highlights the enduring relevance of directly-heated cathodes. Many enthusiasts argue that the sound produced by tube amplifiers, which often utilize directly-heated cathodes, is richer and more pleasing than that produced by solid-state amplifiers. This preference underscores the unique characteristics of directly-heated cathodes and their impact on audio fidelity.In conclusion, the directly-heated cathode (直接加热阴极) is a vital component in the realm of electronics, offering both advantages and challenges. Its ability to efficiently emit electrons directly from a heated filament has made it indispensable in various applications, from vintage audio equipment to modern scientific instruments. As technology continues to evolve, the role of directly-heated cathodes will likely expand further, bridging the gap between traditional and contemporary electronic systems.