Electronics Basis
Voltage is the difference in charge between two points. It is measured in volts, and represented in equations and schematics by the letter V
.
Current is the rate at which charge is flowing. Current is measured in Amperes (usually just referred to as “Amps”). Amps are represented in equations by the letter I
.
Resistance is a material’s tendency to resist the flow of charge (current). Unit of resistance is “1 Ohm”, defined as the resistance between two points in a conductor where the application of 1 volt will push 1 ampere, or 6.241×10^18 electrons. This value is usually represented in schematics with the greek letter Ω
, which is called omega, and pronounced “ohm”.
Ohm’s Law
Combining the elements of voltage, current, and resistance, Ohm developed the formula:
V = I * R
Where
- V = Voltage in volts
- I = Current in amps
- R = Resistance in ohms
Kirchhoff’s First Law
Summation of all Current in any point of circuit equals to 0
.
Kirchhoff’s Second Law
Summation of all Voltage in any Loop always equals to 0
.