1. Source Conversions
2. Star Delta Transforms
3. Electrical Elements
3.1. Resistors add resistance, R
3.2. Capacitors add capacitance, C
3.3. Inductors add inductance, L
3.4. Reactance, X
3.4.1. 1/X = Susceptance, B.
3.5. impedance, Z
3.5.1. 1/Z= Admittance, Y.
3.6. Voltage source
3.7. Current source
4. Types of Circuits
4.1. Both Series and Parallel Circuits
4.2. Series Circuits
4.2.1. Rs=R1+R2+...+Rn
4.2.2. Is=I1=I2=I3=...=In
4.2.3. V=V1+V2+V3+....Vn
4.2.4. 1/Gs=1/G1+1/G2+1/G3+...+1/Gn
4.2.4.1. Gs=(G1G2)/(G1+G2)
4.2.5. Ls=L1+L2+L3+...+Ln (non-coupled inductors)
4.2.5.1. Ls=M11+M22+M33+M12+M13+M23+M21+M31+M32(coupled inductors)
4.2.6. 1/Cs=1/C1+1/C2+1/C3+...+1/Cn
4.2.7. Switches: Two or more switches in series form a logical AND; the circuit only carries current if all switches are closed.
4.2.8. Cells and batteries:A battery is a collection of electrochemical cells.If the cells are connected in series, the voltage of the battery will be the sum of the cell voltages.
4.3. Parallel Circuits
4.3.1. 1/Rp=1/R1+1/R2+...+1/Rn
4.3.1.1. Rp=R1R2/(R1+R2) for resistors
4.3.1.2. Rp=R/n for n number of equal resistors of resistance R
4.3.2. Vp=V1=V2=V3=....=Vn
4.3.3. Itotal=V(1/R1+1/R2+1/R3+....+1/Rn)
4.3.3.1. Ii=V/Ri
4.3.3.2. I1/I2=R2/R1 for 2 resistors
4.3.4. Gp=G1+G2+G3+...+Gn
4.3.5. Lp=1/L1+1/L2+1/L3+...+1/Ln for non-coupled inductors
4.3.5.1. If the mutual inductance between two coils in parallel is M,1/Lp=(L1+L2-2M)/(L1L2-M^2)
4.3.5.1.1. If the mutual inductance between two coils in parallel is M, Lp=(L+M)/2
4.3.6. Cp=C1+C2+C3+...+Cn
4.3.7. Switches: Two or more switches in parallel form a logical OR; the circuit carries current if at least one switch is closed.
4.3.8. Cells and batteries: If the cells of a battery are connected in parallel, the battery voltage will be the same as the cell voltage, but the current supplied by each cell will be a fraction of the total current.
4.3.8.1. Parallel-connected batteries were widely used to power the valve filaments in portable radios. Lithium-ion rechargeable batteries (particularly laptop batteries) are often connected in parallel to increase the ampere-hour rating. Some solar electric systems have batteries in parallel to increase the storage capacity; a close approximation of total amp-hours is the sum of all amp-hours of in-parallel batteries.