Practical Electronics/Band Pass Filter

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Band Pass Filter[edit]

Band Pass Filter can be constructed from joining Low Pass Filter network with High Pass Filter network . Therefore, Band Pass Filters can be constructed from joining

LR and CR
RC and RL

Band Pass Filter LR + CR[edit]

Band Pass Filter LR + CR has a stable voltage over a band of frequencies from \frac{R}{L} to \frac{1}{RC} as long as

\frac{1}{RC} > \frac{R}{L}
R < \frac{L}{C}

Band Pass Filter RC + RL[edit]

Band Pass Filter RC + RL has a stable voltage over a band of frequencies from \frac{1}{RC} to \frac{R}{L} as long as

\frac{R}{L} > \frac{1}{RC}
R > \frac{L}{C}

Summary[edit]

In general Band Pass Filter can be constructed by joining

  1. RC and RL that has a band pass from \frac{1}{RC} to \frac{R}{L}
  2. LR and CR that has a band pass from \frac{R}{L} to \frac{1}{RC}
Filters Band Pass R,L,C 's Value
LR - CR \frac{R}{L} - \frac{1}{CR} \frac{1}{CR} > \frac{R}{L}
RC - RL \frac{1}{CR} - \frac{R}{L} \frac{R}{L} > \frac{1}{CR}