When the workflow looks simplistic, it represents the detailed

When talking about workflows and circuits in a broadcast context, we are referring to any steps of a broadcast from acquisition to transmission. This essay will explore three examples of  workflows: the process of the radio (from transmitter to receiver); how television is transmitted to the public; and the workflow of a CCD camera. The workflows are presented as flow charts, demonstrating simplified step-by-by version of the relevant process. By looking at these examples, we can further our understanding of what workflows and circuits are in a broadcast context.This first workflow shows the way radio waves are transmitted and received:Step 1 and 2: The workflow of a radio transmitter to receiver exemplifies the use of circuits in a broadcasting context. Although the workflow looks simplistic, it represents the detailed process of how radio transmissions work. Firstly, an oscillator is connected to a power supply which converts the current from a Direct Current (DC) to Alternating Current (AC). This is safer as it is easier to maintain and alter the voltage of AC electricity for transmission and distribution.  It is also more efficient to send electricity large distances with a high voltage which is proved by Ohm’s Law (I = P/V). This equation shows that the power consumed by the wires is directly proportional to the resistance of the wires. Therefore by using a higher voltage, it reduces the current, which makes electrical systems more efficient. AC can reach a high voltage as it constantly changes polarity, as it sends the current back and forth through the circuit.Step 3: After the current has been converted to AC, it is then fed into the modulator. Audio information is input into this electronic device and is modulated so that it is ready to be transmitted. The most familiar radio systems used are Frequency Modulation (FM) or Amplitude Modulation (AM) to carry the radio broadcast. The main difference between these two radio systems is that in AM the carrier wave is modulated in amplitude where the frequency and phase remain the same but in FM the carrier wave is modulated in frequency where the amplitude and phase remain the same. Also, AM and has a lower bandwidth so it can have more stations available in any frequency range, is cheaper than FM and can be transmitted over longer distances but has poorer sound quality. Whereas, an FM wave is less likely to have inference but these waves are impacted by physical barriers. These modulated waves are then ready for the next process in the workflow.Step 4: These modulated signals are then fed through an amplifier, which boosts high frequency radio signals. This flows into the transmitter antenna and the electrons in the electric current vibrate along the antenna so that they create electromagnetic radiation (radio waves). These radio waves then travel through the air at the speed of light and are received by a Radio Frequency (RF) antenna.Step 5:  The RF antenna reverses the process done by the first amplifier antenna as the radio waves make the electrons vibrate in the receiver to produce an electric current. Step 6: This current created in Step 5 is then received by the tuner which converts the carrier frequency and its bandwidth which it is associated with into a fixed frequency. This is normally a lower frequency as this is used on the output.Step 7: A detector can also be referred to as a demodulator. It reverses the action of the modulator as it decodesthe modulated radio wave. This device can be easily created at home using a crystal diode (crystal radio circuit).Crystal radio circuits can be easily made at home as it is the simplest type of radio receiver using wire (for an antenna), a coil of wire, a capacitor, a crystal detector and earphones. It doesn’t need external power or battery as it uses the power of the received radio signal. However, because of this, sensitive earphones are needed as it produces a weak sound and can only receive stations within a limited range. More commonly used nowadays are circuits with transistors or semiconductor diodes which are all integrated. Step 8 and 9: This audio is then amplified as it increases the power of the radio signal so that it is strong enough for the speaker. This is because an electromagnet in the speaker translates the electrical signal. A metal coil is used as an electromagnetic as it creates a magnetic field when a current flows through it. As pulses of electricity flow through the metal coil of the electromagnet, the direction of the magnetic field changes very quickly so making it vibrate back and forth. These vibrations are amplified when the electromagnet is attached to a cone made of a flexible material, so pump the sound waves into the surrounding air and these vibrations are translated by our brains into sound. Thus, ending our workflow of radio transmitter to receiver.Next this essay shall focus on the workflow which demonstrates the process of how television can be transmitted to the public at home from a broadcast facility. There are several different methods which that TV can be distributed; DVB-S, DVB-T, the internet and via cable. This is a more complex workflow than the previous example as there are numerous branches from the broadcast facility. By using a workflow it makes it easier visualise. This workflow shows these four branching options from the initial broadcast facility and their subsequent steps:Let us first examine the method of DVB-S transmission. This is Digital Video Broadcasting – Satellite which means the signals from the broadcast facility need an uplink (a link from a ground station up to a satellite) and then this signal is boosted to a satellite in space, ready to be received by a downlink satellite on the home. An advantage of this system is that the signals can travel a vast distance, all around the world.Next we have a similar process, DVB-T which is Digital Video Broadcasting – Terrestrial which means instead of going to a satellite in space, it is transmitted from an antenna on earth and received by a house antenna. This means this the signals can’t span as far so are for closer transmission. For example, it would be used for a national TV service but would not be suitable for an international one. Another way to transmit television is using the internet. The signal goes from the broadcast facility to a server which is separated into different network methods; 3G/4G, WiFi and LAN/Ethernet cable. 3G and 4G networks are commonly known as they are  how your phone connects to the internet when you don’t use WiFi. The ‘G’ stands for generation, so as the numbers increase the more advanced the service is. For a network to be classed as these different generations, there are a set of technical standards referring to the speed and reliability. For example 3G is required to offer peak data transfer rates of least 200 kilobits per second. However, 4G must offer peak data rates of at least 100 megabits per second. 5G communications is the next standard which is likely to be launched this year. This should offer users at least 1 gigabit per second and could be upto 10 gigabits per second.All these internet signals can then be used by numerous pieces of technology in the home like laptops, tablets, smart mobile phone and smart TVs, making it nowadays so much easier to access. The last branch of this workflow to look at is the Cable Television Headend which is a main facility that processes and distributes television signals over a cable system. This is then fed directly into your home by a fibre cable, hence the term ‘cable TV’. The workflow of a Charged Coupled Device (CCD) camera is shown below: Step 1: The image is received into the CCD chip. The CCD chip is an integrated circuit which is an array of little boxes which are individual light sensors, more commonly known as pixels. The photons fall onto these pixels during an exposure; if the exposure is too long, too much light falls on these pixels and it causes overexposure and the image is distorted. The more sophisticated  cameras have three CCD chips. This means that they havethree channel CCD sensors, consisting of the primary colours – blue, red and green light. By having the three chips, there is a larger range in colour and thus they have superior colour reproducibility.Step 2 and 3: This information is fed into the pixel multiplexer. This device arranges the pixels on the CCD chip to have its signal (amount of light gathered) applied to the Analogue to Digital (A/D) converter. It converts the energy from the photons to an electrical charge which is then converted to a voltage and can be processed further by the A/D converter. The different voltages of the pixels are then classified into brightness levels and assign each level to a binary number, consisting of zeros and ones. So the purpose for this is to convert a voltage to a number a computer can then process. CCD digital cameras use at least an 12-bit A/D converter which allows up to 4096 (212) values for the brightness of a single pixel.Step 4 and 5: These binary numbers are passed onto the Data Formatting function. This is where the data is arranged into a file and stored on the memory before it is then transferred onto a computer.In conclusion, workflows are useful in the broadcast industry as they convey complicated processes as simpler steps, making it easier to identify the different stages and each of their purposes. The three examples in this essay demonstrate what workflows and circuits are in the broadcast industry. They show how they can be useful in explaining more complex or branching steps such as the second workflow – the way television can  be distributed to the public – as it helps picture the process to better understand it.BibliographyCooper, Andy. n.d. Practical Electronics.Lowe, Doug. 2017. Electronics All-In-One For Dummies. Hoboken, N.J.: John Wiley & Sons.