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Typical Application Of Band-pass Filters
Sep 06, 2018

Many sound equipment spectrum analyzers use this circuit as a bandpass filter to select signals of different frequency bands and use the amount of light emitting diode on the display to indicate the size of the signal amplitude. The central frequency of the active bandpass filter, the voltage gain Ao= b3/2b1 at the central frequency fo, the quality factor, and the 3dB bandwidth B=1/(programming *R3*C) can also be calculated according to the values of Q, fo and Ao determined by the design. R1 = Q/(2 п foAoC), R2 = Q/(q2 (2 - Ao) * 2 п foC), R3 = 2 Q / 2 п (foC). In the above equation, when fo=1KHz, C is 0.01Uf. This circuit can also be used for general frequency selective amplification. Active bandpass filter circuit


This circuit can also use a single power source, simply by deflecting the input end of the amplifier and amplifier at 1/2 v + and connecting the lower end of the resistance R2 to the input end of the amplifier and amplifier.