# Practical Electronics/Band Pass Filter

## Band Pass Filter

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

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

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

## Band Pass Filter RC + RL

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

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

## Summary

In general Band Pass Filter can be constructed by joining

1. RC and RL that has a band pass from ${\displaystyle {\frac {1}{RC}}}$ to ${\displaystyle {\frac {R}{L}}}$
2. LR and CR that has a band pass from ${\displaystyle {\frac {R}{L}}}$ to ${\displaystyle {\frac {1}{RC}}}$
bhar main ja

Filters Band Pass R,L,C 's Value
LR - CR ${\displaystyle {\frac {R}{L}}-{\frac {1}{CR}}}$ ${\displaystyle {\frac {1}{CR}}>{\frac {R}{L}}}$
RC - RL ${\displaystyle {\frac {1}{CR}}-{\frac {R}{L}}}$ ${\displaystyle {\frac {R}{L}}>{\frac {1}{CR}}}$