Practical Electronics/Voltage Divider

Intro

A network of two resistors connected as shown

Analysis

V_o = I R₂

$I=\frac{V_i}{R_1+R_2}$

$V_o=I{R}_2=\frac{R_2}{R_1+R_2}{V}_i$

Formula

$V_o=\frac{R_2}{R_1+R_2}{V}_i$

Choosing Value for R

• R₂

R₂ = 0 , V_o = 0

R₂ >> R₁ , V_o = V_i

• R₁

R₁ = 0 , V_o = V_i

R₁ >> R₂ , V_o = 0

• R₁ = R₂

V_o = ½ V_i

When R₁ = R₂ , the output voltage is exactly halved of the input voltage

Summary

There is no gain for this network, since V_o never greater than V_i .

This network can be used as Voltage Attenuator, Voltage Follower, Voltage Halved, or Voltage Ground

• When the value of R₂ > R₁, this network acts as Voltage Attenuator

• When the value of R₂ = 0 or R₁ >> R₂, this network acts as Voltage Ground

• When the value of R₁ = 0 or R₁ << R₂, this network acts as Voltage Follower

• When the value of R₂ = R₁ = R then this network acts as Voltage Halved