Practical Electronics/Voltage Divider

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Contents

[edit] Intro

A network of two resistor connected as shown

[edit] Analysis

Vo = I R2
I = \frac{V_i}{R_1+R_2}
V_o = I R_2 = \frac{R_2}{R_1+R_2} V_i

[edit] Formula

V_o = \frac{R_2}{R_1+R_2} V_i


[edit] Choosing Value for R

  • R2
R2 = 0 , Vo = 0
R2 >> R1 , Vo = Vi
  • R1
R1 = 0 , Vo = Vi
R1 >> R2 , Vo = 0
  • R1 = R2
Vo = ½ Vi
When R1 = R2 , the output voltage is exactly halved of the input voltage

[edit] Summary

There is no gain for this network, since Vo never greater than Vi .

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
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