The calculation formula related to capacitance
1, a capacitor, if with 1 library of electricity when the potential difference between the two stages is 1 volt, the capacitance of this capacitor is 1 method, that is: C=Q\/U
two
However, the size of the capacitor is not determined by Q (charge) or U (voltage), i.e. : C=εS\/4πkd. Where ε is a constant, S is the opposite area of the capacitor plate, d is the distance of the capacitor plate, and k is the electrostatic constant. For common parallel plate capacitors, the capacitance is C=εS\/d. (ε is the dielectric constant of the medium between plates, S is the plate area, and d is the distance between plates.)
3, the capacitor potential energy calculation formula: E=CU^2\/2=QU\/2
4, multi-capacitor parallel calculation formula: C=C1 C2 C3... Cn multi-capacitor series calculation formula: 1\/C=1\/C1 1\/C2... 1\/Cn
five
The blocking effect of the capacitor on the AC with high frequency is reduced, that is, the capacitive reactance is small, and the capacitive reactance of the capacitor on the AC with low frequency is large. For the same frequency of AC electricity. The larger the capacity of the capacitor, the smaller the capacitive reactance, and the smaller the capacity, the greater the capacitive reactance
6, series voltage division ratio: the larger the capacitor, the smaller the voltage. Parallel shunt ratio: the larger the capacitor, the larger the current.
When t= RC, capacitance voltage =0.63E; When t= 2RC, the capacitance voltage is 0.86E; When t= 3RC, capacitance voltage =0.95E; When t= 4RC, capacitance voltage =0.98E; When t= 5RC, capacitance voltage =0.99E;
T units, S units, R units, ohms, C units, F units
8, T time voltage: Vt=V0 (V1-V0)*[1-exp(-t\/RC)]
Charge and discharge time: T=RC*Ln[(V1-V0)\/(v1-vt)]