The Capacitor

BASIC CAPACITOR FORMULAS

I. Capacitance (farads) XI. Equivalent Series Resistance (ohms) English: C =.224 K A E.S.R. = (D.F.) (Xc) = (D.F.) / (2 π fC) T
D XII. Power Loss (watts) Metric: C =.0884 K A Power Loss = (2 π fCV
2 ) (D.F.) T
D XIII. KVA (Kilowatts) II. Energy stored in manufacturers of capacitors (Joules, watt - sec)
2 -3 E =
1 �
2 CV
2 KVA = 2 Ï€ fCV x 10 III. Linear charge of a capacitor (Amperes) XIV. Temperature Characteristic (ppm/°C)
25 6 I = CdV T.C. =Ct – C x 10 dt C
25 (T
t – 25) IV. Total Impedance of a capacitor (ohms) XV. Cap Drift (%) Z = R
2 2 1 – C
2 S + (XC- XL) C.D. =C x 100C
1 V. Capacitive Reactance (ohms) XVI. Reliability of Ceramic capacitors xc=12 π fC L
=V

(

t

)(

XT
t

)

Y L
t V
o T
o VI. Inductive Reactance (ohms) XVII. Capacitors in Series (current the same) x
L = 2 Ï€ fL Any Number: 1 VII. Phase Angles: = 1 + 1 --- 1 CTC C CN Ideal Capacitors: Current leads voltage 90°Ideal Inductors: Current lags voltage 90° Ideal Resistors: Current in phase with voltage
1 2 Two: CT=C C
1 C
2 1 + C
2 VIII. Dissipation Factor (%) XVIII.Capacitors in Parallel (voltage the same) CT= C
1 + C
2 ---+ CN D.F.= tan (loss angle) =E.S.R. = (2 Xc π fC) (E.S.R.) XIX. Aging Rate IX. Power Factor (%) A.R. = % C/decade of time P.F. = Sine (loss angle) = Cos

f

(phase angle)P.F. = (when less than 10%) = DF XX. Decibels

D

1 X. Quality Factor (dimensionless) db = 20 logV V
2 Q = Cotan (loss angle) =1D.F.

METRIC PREFIXES SYMBOLS

PicoX 10

-12 K= Dielectric Constantf= frequencyL t = Test lifeA= AreaL= InductanceV

NanoX 10

-9

MicroX 10

-6 t = Test voltageT

MilliX 10

-3 = Dielectric thickness = Loss angleV = Operating voltageV= Voltage

DeciX 10

-1 D o

DecaX 10

+1 = Phase angleT t = Test temperaturet= timeX & Y= exponent effect of voltage and temp.T

KiloX 10

+3

f

MegaX 10

+6 o = Operating temperatureRs= Series ResistanceL

GigaX 10

+9

TeraX 10

+12 o = Operating life

9