Applications Amplifiers Have Many Useful Applications In Electronics.
Amplifiers have many useful applications in electronics. Similarly, transistors can be used for more than just amplification. What are some of the types of amplifiers and what are their classifications?
In your own words compare the applications of different amplifier types and classes.
Explain what is meant by 'TFT' that you always find in the specs for laptop displays.
Discuss an application of Darlington Pair transistors.
Sample Solution
There are several types of amplifiers that can be broadly classified into three main categories: voltage, current and power amplifiers. Voltage amplifiers boost the voltage level of a signal while maintaining its waveform characteristics; these are commonly used in audio systems. Current amplifiers amplify current signals, typically from low-level sources such as microphones or transducers, while also preserving original signal integrity; they are commonly found in medical imaging equipment and process control systems. Power amplifiers provide higher levels of amplification than either voltage or current amplifiers and are suitable for high-power applications such as loudspeakers and radio transmitters. The classifications of amplifier refer to the type of biasing used in their design – Class A, B, AB, C or D. Class A is the most basic type which uses a single transistor biased to operate throughout its entire cycle; it is suitable for low-power applications where distortion needs to be kept at a minimum. Class B designs use two transistors which cuts off during part of each cycle to increase efficiency but has higher distortion levels compared to class A models. Class AB combines elements from both classes A & B with one transistor biased close to cutoff so there is less crossover distortion yet still offers higher efficiency than class A designs. Lastly, Classes C & D have even more complex biasing configurations which allow them run further away from cutoffs resulting in higher efficiencies but come with greater distortions compared to other classes.
Firstly, Vittola discusses one of the just causes of war, most importantly, is when harm is inflicted but he does mention the harm does not lead to war, it depends on the extent or proportionality, another condition to jus ad bellum (Begby et al (2006b), Page 314). Frowe, however, argues the idea of “just cause” based on “Sovereignty” which refers to the protection of political and territorial rights, along with human rights. In contemporary view, this view is more complicated to answer, given the rise of globalisation. Similarly, it is difficult to measure proportionality, particularly in war, because not only that there is an epistemic problem in calculating, but again today’s world has developed (Frowe (2011), Page 54-6).
Furthermore, Vittola argues war is necessary, not only for defensive purposes, ‘since it is lawful to resist force with force,’ but also to fight against the unjust, an offensive war, nations which are not punished for acting unjustly towards its own people or have unjustly taken land from the home nation (Begby et al (2006b), Page 310&313); to “teach its enemies a lesson,” but mainly to achieve the aim of war. This validates Aristotle’s argument: ‘there must be war for the sake of peace (Aristotle (1996), Page 187). However, Frowe argues “self-defence” has a plurality of descriptions, seen in Chapter 1, showing that self-defence cannot always justify one’s actions. Even more problematic, is the case of self-defence in war, where two conflicting views are established: The Collectivists, a whole new theory and the Individualists, the continuation of the domestic theory of self-defence (Frowe (2011), Page 9& 29-34). More importantly, Frowe refutes Vittola’s view on vengeance because firstly it empowers the punisher’s authority, but also today’s world prevents this action between countries through legal bodies like the UN, since we have modernised into a relatively peaceful society (Frowe (2011), Page 80-1). Most importantly, Frowe further refutes Vittola through his claim that ‘right intention cannot be used as an excuse to wage war in response to anticipated wrong,’ suggesting we cannot just harm another just because they have done something unjust. Other factors need to be considered, for example, Proportionality.
Thirdly, Vittola argues that war should be avoided (Begby et al (2006b), Page 332) and that we should proceed circumstances diplomatically. This is supported by the “last resort” stance in Frowe, where war should not be permitted unless all measures to seek diplomacy fails (Frowe (2011), Page 62). This means war shouldn’t be declared until one party has no choice but to declare war, in order to protect its territory and rights, the aim of war. However, we can also argue that the war can never be the last resort, given there is always a way to try to avoid it, like sanctions or appeasement, showing Vittola’s theory is flawed.
Fourthly, Vittola questions upon whose authority can demand a declaration of war, where he implies any commonwealth can go to war, but more importantly, “the prince” where he has “the natural order” according to Augustine, and all authority is given to him. This is further supported by Aristotle’s Politics ((1996), Page 28): ‘a king is the natural superior of his subjects.’ However, he does later emphasise to put all faith in the prince is wrong and has consequences; a thorough examination of the cause of war is required along with the willingness to negotiate rival party (Begby et al (2006b), Page 312& 318). This is supported by the actions