中心频率可调的带通滤波器电路图(a Tunable Band-Pass Filter)
下图是一采用uA741运放组成的通频带可调的带通滤波器电路图。通过调节电阻R2可调节中心频率。
This is a circuit that can be tuned to only allow input signals within a certain range of frequencies to pass to the output, hence the name 'tunable band-pass filter'. All signals with frequencies lower or higher than this range are attenuated (weakened or decreased in level) by this circuit.
The circuit is an active filter that uses a 741 operational amplifier IC configured to pass a narrow band of frequencies ranging from a few hundred hertz to about 3 kHz. This circuit may be used to detect the presence of a tone in this frequency range. Variable resistor R2 is used to 'tune' the center frequency of this filter.
图1. 中心频率可调的带通滤波器电路图