电容器

Add subjects, save guides and continue where you left off with your BBC account. 1. Electrolytic capacitors – these are polarised, so they have a positive and a negative leg. Usage : applications requiring large capacitance values, such as timing circuits and power supplies. 2. Ceramic capacitors – these are non-polarised. Usage : applications like signal smoothing. Choose capacitors based on the required capacitance, voltage rating, and whether the circuit requires a polarised or non-polarised capacitor. Stage 1 : The 9V battery sends electrical charge to the capacitor's plates, allowing it to store energy (like filling a tank). The capacitor continues charging until it's full. Stage 2: When the SPDT switchcloseSingle pole, double throw (SPDT) switchA type of electrical switch that allows you to connect a single input to one of two outputs. It has has one input terminal (the pole) and two output terminals (the throws). is manually pressed, the battery is now cut off from the rest of the circuit. However, the stored energy from the capacitor can now flow through the circuit, making the LED light up briefly. The resistor will control the discharge rate of the capacitor by limiting the flow of current through the circuit. If you know any two of these quantities, you can calculate the third.