Active filter circuits are used especially in audio circuits. There are various circuits generally based on op amp integrated circuits for bass, treble etc. sounds. The general structure of the circuits consists of very simple resistors and capacitors. The main controller is the op amp integrated circuit. The supply legs of the integrated circuit are not specified in the schematics. Pay attention to this in the application. tl082, tl071, ne5532, tl074, tl084, tl081 op amps can be used. The supply legs are found in the datasheet information of the integrated circuits.
Bessel 12dB High pass (2nd order filter, 12dB/octave, high pass)
C=4.7n-10nF
Ra=1.1017/(2*pi*Fc*C)
Rb=1.4688/(2*pi*Fc*C)
Units: Rx [Ohm], C [F], Fc [Hz]
Bessel 12dB Low Pass (2nd order filter, 12dB/octave, low pass)
R=4.7k-10 kOhm
Ca=0.9076/(2*pi*Fc*R)
Cb=0.6809/(2*pi*Fc*R)
Units: R [Ohm], Cx [F], Fc [Hz]
Bessel 18dB High pass (3rd order filter, 18dB/octave, high pass)
C=4.7n-10nF
Ra=1.0474/(2*pi*Fc*C)
Rb=2.0008/(2*pi*Fc*C)
Rc=1.3228/(2*pi*Fc*C)
Units: Rx [Ohm], C [F], Fc [Hz]
Bessel 18dB Low Pass (3rd order filter, 18dB/octave, low pass)
R=4.7k-10 kOhm
Ca=0.9548/(2*pi*Fc*R)
Cb=0.4998/(2*pi*Fc*R)
Cc=0.7560/(2*pi*Fc*R)
Units: R [Ohm], Cx [F], Fc [Hz]
Bessel 24dB High pass (4th order filter, 24dB/octave, high pass)
C=4.7n-10nF
Ra=1.3701/(2*pi*Fc*C)
Rb=1.4929/(2*pi*Fc*C)
Rc=0.9952/(2*pi*Fc*C)
Rd=2.5830/(2*pi*Fc*C)
Units: Rx [Ohm], C [F], Fc [Hz]
Bessel 24dB Low Pass (4th order filter, 24dB/octave, low pass)
R=4.7k-10 kOhm
Ca=0.7298/(2*pi*Fc*R)
Cb=0.6699/(2*pi*Fc*R)
Cc=1.0046/(2*pi*Fc*R)
Cd=0.3872/(2*pi*Fc*R)
Units: R [Ohm], Cx [F], Fc [Hz]
Butterworth 6dB High pass (1st order filter, 6dB/octave, high pass)
C=4.7n-10nF
R=1.000/(2*pi*Fc*C)
Units: R [Ohm], C [F], Fc [Hz]
Butterworth 6dB Lowpass (1st order filter, 6dB/octave, low pass)
R=4.7k-10 kOhm
C=1.000/(2*pi*Fc*R)
Units: R [Ohm], C [F], Fc [Hz]
Butterworth 12dB High pass (2nd order filter, 12dB/octave, high pass)
C=4.7n-10nF
Ra=0.7071/(2*pi*Fc*C)
Rb=1.414/(2*pi*Fc*C)
Units: Rx [Ohm], C [F], Fc [Hz]
Butterworth 12dB Low pass (2nd order filter, 12dB/octave, low pass)
R=4.7k-10 kOhm
Ca=1.414/(2*pi*Fc*R)
Cb=0.7071/(2*pi*Fc*R)
Units: R [Ohm], Cx [F], Fc [Hz]
Butterworth 18dB High pass (3rd order filter, 18dB/octave, high pass)
C=4.7n-10nF
Ra=0.500/(2*pi*Fc*C)
Rb=2.000/(2*pi*Fc*C)
Rc=1.000/(2*pi*Fc*C)
Units: Rx [Ohm], C [F], Fc [Hz]
Butterworth 18dB Low pass (3rd order filter, 18dB/octave, low pass)
R=4.7k-10 kOhm
Ca=2.000/(2*pi*Fc*R)
Cb=0.500/(2*pi*Fc*R)
Cc=1.000/(2*pi*Fc*R)
Units: R [Ohm], Cx [F], Fc [Hz]
Butterworth 24dB High pass (4th order filter, 24dB/octave, high pass)
C=4.7n-10nF
Ra=0.9239/(2*pi*Fc*C)
Rb=1.0824/(2*pi*Fc*C)
Rc=0.3827/(2*pi*Fc*C)
Rd=2.6130/(2*pi*Fc*C)
Units: Rx [Ohm], C [F], Fc [Hz]
Butterworth 24dB Low pass (4th order filter, 24dB/octave, low pass)
R=4.7k-10 kOhm
Ca=1.0824/(2*pi*Fc*R)
Cb=0.9239/(2*pi*Fc*R)
Cc=2.6130/(2*pi*Fc*R)
Cd=0.3827/(2*pi*Fc*R)
Units: R [Ohm], Cx [F], Fc [Hz]
Linkwitz 24dB High pass (4th order filter, 24dB/octave, high pass)
C=4.7n-10nF
Ra=Rc=1/(2*sqr(2)*pi*Fc*C)
Rb=Rd=2Ra
Units: Rx [Ohm], C [F], Fc [Hz]
Linkwitz 24dB Low pass (4th order filter, 24dB/octave, low pass)
R=4.7k-10 kOhm
Ca=Cc=2*Cb
Cb=Cd=1/(2*sqr(2)*pi*Fc*R)
Units: R [Ohm], Cx [F], Fc [Hz]
Published: 2011/06/19 Tags: audio control circuits
Camera High Voltage Flash Circuit
Earlier in cameras that flash lamp theriac be run with about a circuit I shared this article on the flash circuit diagrams original most famous brands (kodak, canon etc. ..) photographs of works dealing with some people, this circuit using the camera in addition to the flash module is doing the camera casing modified whether the flash-lamp circuits have been made to place them also in the repair work may work for you.
A few examples of the circuits