Seektronics

We all know that capacitor  voltages cannot change abruptly and inductor  currents cannot change abruptly, what is the theoretical basis for this?   Take an example of an RC first-order low-pass filter.   Vin charges capacitor C1 through the R1 resistor, the potential of Vin is added to the two metal pole plates of capacitor C. The positive and negative charges are gathered towards the two-pole plates of the capacitor respectively under the effect of the potential difference and an electric field is formed, which is the charging process of the capacitor. Charging of capacitors   The charge number, which measures the charge of a capacitor, is Q，Q = CV and C is a constant, so the charge number is proportional to the voltage.   C = Q/V, the capacity represents the ability of the capacitor to store charge and the differential expression is： Current is the amount of change in the number of charges per unit of time： Combining the two equations (1) and (2) yields： It follows from the formula