Voltage Divider

Written by Jerry Ratzlaff on . Posted in Electrical Engineering

Voltage divider is two resistances connected in series across a supply voltage.

Voltage Divider formulas

 $$\large{ V_o = \frac { R_2 }{ R_1 \;+\: R_2 } \; V_i }$$ $$\large{ V_o = \frac { 1 }{ 2 } \; V_i \;\;}$$  $$\large{if}$$   $$\large{\;\; R_1 = R_2 }$$ $$\large{ V_o = I \; R_2 }$$

Where:

 Units English Metric $$\large{ V_o }$$ = output voltage $$\large{I\;R}$$ $$\large{V}$$ $$\large{ V_i }$$ = input voltage $$\large{I\;R}$$ $$\large{V}$$ $$\large{ R_1 }$$ = resistance $$\large{\frac{V}{I}}$$ $$\large{R}$$ $$\large{ R_2 }$$ = resistance $$\large{\frac{V}{I}}$$ $$\large{\Omega}$$ $$\large{ I_o }$$ = output current $$\large{\frac{V}{R}}$$ $$\large{I}$$ $$\large{ I_i }$$ = input current $$\large{\frac{V}{R}}$$ $$\large{I}$$

Solve for:

$$\large{ V_i = I \; { R_1 \;+\: R_2 } }$$

$$\large{ I_o = \frac { V_i }{ R_1 \;+\: R_2 } \; I_i }$$

Tags: Electrical Equations