A Comprehensive list of Electronic Formulasby Leobot

Tutorials & Guides

These tutorials & guides are intended to help beginners in the field of electronics get started or provide some insight into a specific component.

A Comprehensive list of Electronic Formulas

A List of all formulas relating to Electronics

Guide

Electronic Formulas

Here is a comprehensive list of all of the key formulas involved in Electronics. The formulas are divided into sections in order of simplicity and importance to the more complex:

Voltage, Resistance and Current

The most elementary concepts are the most important to understand. These are all the formulas dealing with electrical conduction properties of materials.

Essential Basic Electronic Formulas
FORUMLA	Attribute	Explanation	Variables
Q = (Number of Electrons)/(6.25*10^18)	Charge	Charge is the basic unit of Energy used in electronics. Charge is means a material has either an excess of electrons or a deficiency of Electrons. 6.25*10^18 Electrons's worth of energy is 1 Coulumb's worth of Charge.	Q represents Charge.
V = W/Q	Voltage	Voltage is the amount of energy for each unit of Charge	V represents Volts. W represents Joules. Q represents Charge.
I = Q/t	Current	Current is the amount of Charge per second (t) that passes through a point in the circuit.	I represents Current. Q represents Charge. t represents Time in Seconds
G = 1/R	Conductance	Conductance is the invert of Resistance and represents how easy it is for electrons to flow.	G represents Siemens. R represents Resistance in Ohm.
A = d^2	Cross-sectional	The cross-sectional Area in a circular mils conductor is equal to the diameter in mils squared.	A represents Cross Sectional Area. d represents diamter in mils.
R = (p*l)/A	Resistance	Resistivity in (CM OHM Resistivity of Material per ft) times the length of the material divided by the Cross-Sectional Area	R represents Resistance p represents CM Ohm Resistance per foot. l represents the length of the material. A represents the Cross Sectional Area.

Ohm's Law and Kirchoff's Law

Ohm's Law provides the link to work with Curent,Voltage and Resistance directy.

Ohm's Law Electronic Formulas
FORUMLA	Attribute	Explanation	Variables
I = V/R	Current		Q represents Charge.
V = I*R	Voltage		V represents Volts. W represents Joules. Q represents Charge.
R = V/I	Resistance		I represents Current. Q represents Charge. t represents Time in Seconds
P = W/t	Power		G represents Siemens. R represents Resistance in Ohm.
W = P*t	Energy		A represents Cross Sectional Area. d represents diamter in mils.
P = (I^2)*R	Power		R represents Resistance p represents CM Ohm Resistance per foot. l represents the length of the material. A represents the Cross Sectional Area.
P = (V^2)/R	Power
e = (P_out)/(P_In)	Power Efficiency
P_out= P_in - P_loss	Output Power

Resistance, Voltage and Power in Series circuits

Ohm's Law provides the link to work with Curent,Voltage and Resistance directy. Remember, CURRENT IS THE SAME IN ALL POINTS IN A CIRCUIT BRANCH IN SERIES.

Ohm's Law Electronic Formulas
FORUMLA	Attribute	Explanation	Variables
Rt = R1 + R2 + R3 + ... + Rn	Total Series Resistance	The total resistance in a series circuit is equal to the sum of the resistance of the parts that make up the series circuit.	Rt represents Total Resistance. R1 represents the Resistance of the 1st Resistor in the series. R2 represents the Resistance of the 2nd Resistor in the series. R3 represents the Resistance of the 3rd Resistor in the series. Rn represents the Resistance of the nth Resistor in the series.
Rt = n*R	Total Resistance of n circuit in series	The total resistance of N equal-value resistors in series.	Rt represents Total Resistance. nR represents the number of equal-value resistors in series.
Vs = V1 + V2 + V3 + ... + Vn	Source Voltage	The Source Voltage of a circuit in series is equal to the sum of all the voltage drop over each resistor in series. (Kirchhoff's Voltage Law)	Vs represents the Total Voltage Source supply. V1 represents the Voltage Drop across the 1st Resistor in series. V2 represents the Voltage Drop across the 2nd Resistor in series. V3 represents the Voltage Drop across the 3rd Resistor in series. Vn represents the Voltage Drop across the nth Resistor in series.
Vx = ((Rx)/(Rt))*Vs	Voltage Drop	The Voltage Drop across a resistor is proportional to the resistance of the invidual resistor over the the total resistance of the circuit. This is the Voltage-Divider Formula.	Vx represents the Voltage Drop over a Resistor x. Rx represents the Resistance of Resistor x. Rt represents the Total Resistance of the circuit. Vs represents the total Voltage Source
Pt= P1 + P2+ P3 + ... + Pn	Total Power		Pt represents the Total Voltage Source supply. P1 represents the Power at the 1st Resistor in series. P2 represents the Power at the 2nd Resistor in series. P3 represents the Power at the 3rd Resistor in series. Pn represents the Power at the nth Resistor in series.

Resistance, Current and Power in Parallel circuits

Ohm's Law provides the link to work with Curent,Voltage and Resistance directy. Remember, VOLTAGE IN A PARRELEL CIRCUIT IS THE SAME ACCROSS ALL BRANCHES.

Ohm's Law Electronic Formulas
FORUMLA	Attribute	Explanation	Variables
1/Rt = 1/R1 + 1/R2 + 1/R3+...+ 1/Rn therefore Rt=1/(1/R1 + 1/R2 + 1/R3 + ... + 1/Rn)	Total Parallel Resistance	The total resistance in a parallel circuit is equal to reciprocal of the the sum of the reciprocal resistance of the parts that make up the parallel circuit.	Rt represents Total Resistance. R1 represents the Resistance of the 1st Resistor in the parallel. R2 represents the Resistance of the 2nd Resistor in the parallel. R3 represents the Resistance of the 3rd Resistor in the parallel. Rn represents the Resistance of the nth Resistor in the parallel.
Rt = R/n	Total Parallel Resistance n-equal value resistors in parallel.	The total resistance of N equal-value resistors in series is equal to the value of the resistor divided by the number of resistors.	Rt represents Total Resistance. nR represents the number of equal-value resistors in parallel.
Rt = (R1 * R2) / (R1 + R2)	Total Resistance for two resistors in parallel.	The Source Voltage of a circuit in series is equal to the sum of all the voltage drop over each resistor in series. (Kirchhoff's Voltage Law)
I1 = ((R2)/(R1+R2))It I2 = ((R1)/(R1+R2))It	Current in a two-branch Current Divider circuit.	The Voltage Drop across a resistor is proportional to the resistance of the invidual resistor over the the total resistance of the circuit. This is the Voltage-Divider Formula.
Ix = (Rt/Rx)*It	Current in a general Current Divider circuit.
Gt = G1 + G2 + G3 + ... + Gn	Total Conductance in a Parallel circuit.
Pt = P1 + P2 + P3 + ... + Pn	Total Power in a Parallel circuit.
Iin1 + Iin2 + Iin3 + .... + Iin(n) = Iout1 + Iout2 + Iout3 + ... + Iout(n)	Kirchhoff's Law of Current in Parallel Brances