Department of Electrical Engineering and Electronics ELEC171 Project Practice activity 3: Finding electronic components Overview A key part of any project is identifying the parts that you need to make your circuits work successfully. In the other module activities, you have been given a kit of parts with the components that you need. For the project, you and your team must choose the components that you need for your own circuit. There are two parts to this activity. In one part, you will be introduced to the three large companies who are the main suppliers of electronic components in the UK. The websites for these companies give you a lot of information about the components that they sell. In the second part of the activity, you will be shown how to understand the technical information that component manufacturers provide. Activity Specifications Activity name Suggested study time Assessment Submission deadline Submission form Late submission Resit opportunity Marking policy Anonymous marking Feedback Finding electronic components 3 hours Lab notes for the three practice activities will be assessed together. In total, this will contribute 30% of your project mark. Online via Canvas Standard university penalty applies August resit period Marked and moderated independently Yes via Canvas / Turnitin Feedback Studio 1 2.1 Introduction and aims When you design any electronic circuit, one part of the design process is choosing the components that you will use. Of course, your general design must include some description of the component properties, such as the magnitude of any resistor or capacitor, but any real component has other properties. For resistors, these might include physical properties such as the tolerance, the material it is made from, and the maximum power it can conduct, as well as practical considerations such as the cost and availability. The aims of this part are to introduce you to the main online suppliers of electronic components and enable you to access important information from their websites. 2.2 The three main suppliers There are three main suppliers of electronic components in the UK. Each company has a different style of website, but they all give you all the information that you need to find components. These companies are: https://uk.rs-online.com/web/ https://www.rapidonline.com/ Before you visit a website to search for components, you need to know the specifications of the component that you want. Some characteristics might be important for your application while other characteristics are less important. It depends on what you need. RS components Farnell/OneCall Rapid Electronics As an example, we will consider the case of searching for 100 resistors. This might sound simple, but the suppliers have a large range of parts. For example, if you search the Farnell website for 100 resistors of the type that we use in the lab (called through-hole resistors), the site lists more than 400 different components. With so many choices, the question is how do you decide which of these components is suitable for your project? Manufacturer Part No Figure 2.1 shows a screenshot from the website of one company, showing the first few items that they show. The screenshot is small, but you can see that there is a lot of information about each component. The left side of the screen has general information about the resistors such as the description and price, while the right side has technical information. 1AA9 MCKNPOSSJ010 1903931 Data Sheet V OFC100 Order Code MBB02070C100 2614368 MF12 100R ⒸROHS Part 1: Understanding the suppliers Data Sheet ⒸROHS 9342397 D Data Sheet RoHS Description / Manufacturer Through Hole Resistor, 100 oh m, MCKNP Series, 5 W, 5%, A xial Leaded MULTICOMP PRO Best Seller Through Hole Resistor, 100 oh m, MBB Series, 600 mW, 1%, Axial Leaded, 350 V VISHAY Best Seller www.uk.farnell.com Through Hole Resistor, 100 oh m, MF12 Series, 125 mW, + 1%, Axial Leaded, 200 V MULTICOMP PRO Best Seller Availability 1,021 In stock 183 In stock View Additional Avnet Stock 42,755 In stock Price For Each Each Each Price (ex VAT) hole-resistors?resistance=100ohm 1+ £0.273 10+ £0.234 50+ £0.149 100+ 0.119 200+ £0.0998 More Pricing... 1+ £0.178 50+ £0.0919 100+ £0.0791 250+ £0.0713 500+ £0.0633 More Pricing... Quantity Add Min: 1 Mult: 1 Add Min: 1 Mult: 1 Add 5+ £0.029 50+ £0.0249 250+ £0.019 500+ £0.0159 Min: 5 1000+ £0.0128 Mult: 5 More Pricing... 5 Resistance Product Range 100ohm 100ohm 100ohm MCKNP Series MBB Series MF12 Series Resistance Tolerance + 5% + 1% ±1% Resistor Power Voltage Resistor Case Style Rating Rating Element Type Axial Leaded SW Axial Leaded 600mW 350V Axial Leaded 125mW 200V Wirewound Thin Film Metal Film Figure 2.1: screenshot from Farnell UK, showing some different 100 № resistors. The writing on the image is too small to read easily but you can see that a lot of different information is listed. https://uk.farnell.com/c/passive-components/resistors-fixed-value/through- 2 We will now consider the different information that you can see on this type of website. Figure 2.2 shows an enlargement of part of the left part of the screen. Some important features are: The link to the technical specification sheet: you can download this to get more information The order code: you need to record this if you want to order this item The manufacturer's name: it can be hard to know the difference between the different companies until you have more experience, but it is sometimes useful to use the same company so that you know all the parts should work together. ● ● ● The type of component: this is obviously a resistor, but the important information is that is a "through hole resistor", which means that the resistor has two wire legs that will fit into a test board. This is only one type of mounting system, and if you order the wrong type, you might not be able to test them properly. The level of stock: ideally, you want a component with lots of stock, then you can order more of the same ones later if you need them. If you order a component with low stock, you might not be able to replace it easily. The cost: obviously this is important. The minimum order: this is extremely important. For some components, you can order just a single item but for others, you might have to order 10, or 100, or even a box of 1000. You must check this. link to the full technical specifications Manufacturer Part No MCKNP05SJ010 1AA9 MBB02070C100 OFC100 MF12 100R Order Code order code 1903931 TS W Data Sheet GROHS W 2614368 Data Sheet GROHS 9342397 Data Sheet RoHS type of component - general description manufacturer Description / Manufacturer Though Hole Resistor, 100 oh m, MCKNP Series, 5 W, ± 5%, A xia Leaded MULTICOMP PRO Best Seller Through Hole Resistor, 100 oh m, MBB Series, 600 mW, ± 1%, Axial Leaded, 350 V VISHAY Best Seller Through Hole Resistor, 100 oh m, MF12 Series, 125 mW, + 1%, Axial Leaded, 200 V MULTICOMP PRO Best Seller are they in stock?! Availability 1,021 In stock 183 In stock View Additional Avnet Stock 42,755 In stock Price For Each Each Each cost Price (ex VAT) what is the minimum order? 1+ £0.273 10+ £0.234 50+ £0.149 100+ £0.119 200+ £0.0998 More Pricing... 1+ £0.178 50+ £0.0919 100+ £0.0791 250+ £0.0713 500+ £0.0633 More Pricing... 5+ £0.029 50+ £0.0249 250+ £0.019 500+ £0.0159 1000+ £0.0128 More Pricing... Quantit 1 Add Min: 1 Mult: 1 1 Add Min: 1 Mult: 1 5 Add Min: 5 Mult: 5 Figure 2.2: enlargement of the left side of the screenshot from Figure 2.1, with some of the important features highlighted. 3 Figure 2.3 shows an enlarged version of the left part of the screen. This contains specific technical information. For resistors, some of the important features are highlighted: ● Tolerance: the components we use in the labs usually have 5% tolerance, but you can get components with higher or smaller values than this. Power rating: this is important. Most electronic circuits of the type we investigate have very low power requirements and 125 mW or 250 mW rating is fine. It is not necessarily a mistake to order resistors with higher ratings because the resistance will be the same, but the component might cost more and be bulkier. Voltage rating: for most electronic applications, the voltage rating will be much higher than any voltage expected in the circuit. Even so, it is good to have a high rating so that any sudden brief spikes of voltage do not damage the components. These are just some of the features that you might need to consider when you search for resistors. If you search for other simple components, such as capacitors, different properties will be important. If you are searching for more complicated components, such as integrated circuits, then there might be completely different criteria that matter. You will gain more experience of this as you progress through your degree. Resistance Product Range 100ohm 100ohm 100ohm MCKNP Series MBB Series MF12 Series Resistance Tolerance ± 5% ± 1% ± 1% Resistor Case Style Axial Leaded Axial Leaded Power Rating 5W 600mW Axial Leaded 125mW Voltage Rating 350V 200V Resistor Element Type Wirewound Thin Film Metal Film Figure 2.3: enlargement of the right side of the screenshot from Figure 2.1, with some of the important features highlighted. The screenshots in Figures 2.1, 2.2 and 2.3 are from the page that shows summarised information for a large number of items. If you click on the "manufacturer's part number" link, you will be taken to the supplier site for that particular component. Figure 2.4 below shows the page for the first item on the list. This page has even more information about that specific component. Before you choose any item to order, you should check the detailed information on this site, just to make sure that the component really matches your requirements. Part 3 of this activity contains some guidance on how to do this. All Products Manufacturers Resources Communities Home > Passive Components > Resistors - Fixed Value> Through Hole Resistors BREXIT UPDATE: DUE TO WEATHER RELATED ISSUES IN EUROPE AND ONGOING POST BREXIT CHALLENGES, WE ARE EXPERIENCING ONGOING DELAYS WITH OUR CARRIERS IN DELIVERING NEXT DAY SERVICE. More info MCKNP05SJ0101AA9 Through Hole Resistor, 100 ohm, MCKNP Series, 5 W, ± 5%, Axial Leaded Best Value ● Add to compare Image is for illustrative a poses only. Please refer to product description multicomp PRO This product has been approved for the Multicomp Pro product range. More MULTICOMP PRO Manufacturer: Manufacturer Part No: Order Code: Product Range Ⓡ Technical Datasheet: See all Technical Docs MCKNP05SJ0101AA9 1903931 MCKNP Series MCKNP05SJ0101AA9 Datasheet ♡ Favourites ↑ Tools ex VAT 1,021 In stock > 1,000 more will be available on 03/05/21 3,000 more will be available on 05/07/21 Reserving future stock £0.273 (ex VAT ) Price for: Each Multiple: 1 Minimum: 1 Quantity A Spotted an Error? Order before 6pm (Northern Ireland 6pm) With you next business day Hassle free returns. Terms & Conditions 1+ 10+ 50+ Best Seller inc VAT Part 3: Datasheets for sensor components Print Page Figure 2.4: Farnell site for the first resistor listed from the page shown in Figure 2.1, 2.2 and 2.3. This site has the address https://uk.farnell.com/multicomp/mcknp05sj0101aa9/res-100r-5-5w-axial- wirewound/dp/1903931 Price (ex VAT) £0.273 £0.234 £0.149 3.1 Introduction and aims The aim of this section is show you how you can use the information given by component manufacturers to understand the physical properties of those components. You have already seen how the supplier website provides information about resistors. In this section, we will consider slightly more complicated components: light-emitting diodes (LEDs) and photodiodes. These are a good example for several reasons: they are components that you have used already they are more complicated than a resistor, and you will have to view information provided by the manufacturer, as well as the supplier you will need to use similar components for your robot car, so it is important that you understand them 3.2 Properties of LEDs and photodiodes When you design your robot car, you will have to choose to order one or more different type of light sources and light detectors. If you want to order the most appropriate components, you need to understand the specifications of these types of components. Figure 3.1 shows a robot car with different styles of sensors - you will need to choose what style is appropriate for your own care. You could use an LED that is very bright or a less intense one. You could choose an LED that emits light of a certain colour, such as red or blue, or even one that emits infrared light. You could choose an LED that emits in a very narrow torch-like beam, or one that emits in a wide fan. All of these are reasonable choices, but at some stage you will need to decide what you want. 5