Electronics DNT 7059/01 2023 V/2

Tino/Wei En/ Btyss 2022/2059 Design and Technology 7059/1 Topic on Electronics 1) An electronic system has; - Input; for gathering information. - Process; decide what to do with information - Output; involves with switching device on/off. 2) Feedback – in a system with feedback, the output is fed back to the input, and depending on the outut, the input is adjusted so as to reach a steady- state. - Open-loop control system; - Closed-loop control system; 3) Conductors and Insulators - Electrical conductor; material that allows electricity to flow through easily. - Electrical insulator; material that electricity cannot follow though. - Semi-conductor; electricity can flow through them, but with difficulty. 4) Power Supply 4a) Mains power supply has alternating current. - Advantages; It is more cost-effective and easy to transmit large amounts of power over large distances. 4b) Most common source of power is the battery. Batteries have a positive and negative terminal and it has potential difference (concept linkage w/ Physics, topic of ‘Current of Electricity).

Tino/Wei En/ Btyss 2022/2059 - Potential difference is measured in volts (V) - Batteries in series – add voltage of batteries together to get the total voltage/electromotive force of the source. (Concept linkage w/ Physics, topic of ‘DC Circuits’) - Batteries in parallel – total voltage is same as of individual battery. - Advantage of Batteries; portable, generally of lower power. - Safety; Never short circuit a battery, never break open a battery due to presence of corrosive chemicals, never throw batteries into a fire due to explosive potential. 4c) Photovoltaic cells/ Solar panels – converts light energy into electricity using semi-conductors. - Generally environmentally-friendly 5) Electric Current and Electrical Power 5a) Electrical Current is the rate of charge flow per unit time. - Measured in Amperes (A) 5b) Power is the rate of energy change. - Measured in Watts (W) - 𝑃𝑜𝑤𝑒𝑟 (𝑃) = 𝐶𝑢𝑟𝑟𝑒𝑛𝑡 (𝐼) × 𝑉𝑜𝑙𝑡𝑎𝑔𝑒 (𝑉) 6) Multimeter - To measure current, a Ammeter is used. It must be connected in series with the circuit. - To measure voltage, a voltmeter is used. It must be connected parallel with the circuit. 7) Circuits

Tino/Wei En/ Btyss 2022/2059 Parralel Series If resistance of the different paths in a parallel circuit is the same, current flow will be split equally amongst the separate paths. If resistance of the different paths in a parallel circuit are different, current flow will be higher in the path of lowest resistance. Current is the same at any point in a circuit. (Physics-based explanation; At any point in the circuit, the same amount of charges flow through it. Hence, current flow is the same at any point in a parallel circuit.) The potential difference of each path in the parallel circuit is equal to the electromotive force of the source. The total potential difference of all the