Presentation on theme: "Electrical Theory Quantity Symbol Unit Equation"— Presentation transcript:
1 Electrical Theory Quantity Symbol Unit Equation Charge Q coulomb Q = IIdtCurrent I ampere I = dQ/dtVoltage V volt V = dW/dQEnergy W joule W = IVdt = IPdtPower P watt P =dW/dt = IVResistor R ohm V = IRInductor L henry V = L dI/dtCapacitor C farad V = 1/C IIdt
2 Electrical Theory Ohm’s Law I =V/R (DC) I = V/Z (AC) Kirchoff ’s Law Sum of Loop Voltages = 0Sum of Node Currents = 0Joule’s LawP = IE = I2R (I Squared R Loss)
3 Current Flow Electron Flow - From excess to deficient Conventional Current FlowInternal to Source (Battery)Negative to PositiveExternal from Source (Battery)Positive to NegativeVoltage Drop - Across a Resistor + to -Negative Current - Assumed Direction Reversed
4 Equivalent Circuits Thevenin Two Terminal Resistor and Battery Circuit Series Voltage Source and Equivalent ResistorVoltage Source = Open Circuit VoltageEquivalent Resistor = V / Short Circuit CurrentNortonParallel Voltage Source and Equivalent ResistorCurrent Source = Short Circuit Current
6 DC Circuit Components Component Impedance Current Power Energy R R I = V/R NoneL Zero Infinite WL = 1/2 LI2C Infinite Zero WC = 1/2 CV2
7 AC Sinusoidal Analysis Resistor R I = V/R P = I2R = V2/RInductor jXL= jwL I = -jVL/wL QL= I2XL = VL2/XLCapacitor -jXC= -j/wC I = jVCwC QC= I2XC = VC2/XCCurrent I = IR + j IXVoltage V = VR + j VXComplex Power S = VI* = (VR + j VX)(IR - j IX)Complex Power S = P + j Q
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