lifehacker.com: If you're a beginner electronics hobbyist you know that the capacitors on most battery-operated objects aren't powerful enough to kill you but can still provide a painful jolt of electricity if not discharged before removing from a circuit board. Build a capacitor discharge tool using a resistor, two pieces of 12AWG wire or larger, and heat shrink tubing.
Professor Budnik repeats “Voltage cannot change instantaneously across a capacitor” all the time in Electrical Engineering Lecture. Capacitors are used to charge, store, and discharge electrical energy in circuits. Recently, we’ve been learning how capacitors can act as filters to attenuate specific frequency bands. This is directly connected to audio and theatrical mixing! Sound designers and board operators are constantly thinking about the frequency bands that sound cues and actors’ microphones take up in order to balance “equalize” the outputted sound.
ReplyDeleteHere is how it works! A capacitor can charge up a certain amount of voltage. When it begins charging, since voltage cannot change instantaneously, current flows at its maximum amperage. As it charges, the capacitor begins to act more like an open circuit (which is when there is 0A of current). When it is fully charged, voltage is unchanging. Sound is alternating current, and its voltage changes. So, when the frequency (or rate of change of voltage) is high, there is lots of current through the capacitor. When the frequency is low, and voltage is unchanging, there is less current through the capacitor. This can allow us to discharge high frequencies through the capacitor, and low frequencies pass to other parts of the circuit!
I loved learning from this article how to discharge a capacitor safely.