Practical Electronics/Low Pass Filter

Low Pass FilterEdit

LR NetworkEdit

 
 
 
 
 
 
Plot three points above we have a graph   . From graph, we see voltage does not change with frequency on Low Frequency therefore LR network can be used as Low Pass Filter

RC NetworkEdit

 
 
 
 
 
 
Plot three points above we have a graph   . From graph, we see voltage does not change with frequency on Low Frequency therefore LR network can be used as Low Pass Filter

SummaryEdit

In general

  1. Low Pass Filter can be constructed from the two networks LR or RC .
  2. Low Pass Filter has stable voltage does not change with frequency on Low Frequency
  3. Low pass filter can be expressed in a mathematical form of
 
T = RC for RC network
  for RL network