CKS2006
volume-compressor
The audio compressor or a unity-gain amplifier having an expansion of 3 db and a compression of 12 db around an average level of approximately 45 db below 1 volt at an impedance of 100.000 ohms. The compressor is inserted after the microphone amplifier. The incoming audio signal is amplified by U1a and applied to the diode compressor through C1. The diode compressor is essentially an L-pad attenuator, with R1 forming one leg and diode D3 for the other leg. Diode D1 rectifieds the audio signal and applies the resultant DC voltage through R2 to diode D3. The impedance of D3 varies almost logarithmically in inverse porportion to the DC voltage across it. Diode D2 protects filter capacitor C2 from any reverse polarity switching transients that may be applied from the output. The curves of Fig-2 show that about 15 deb attenuation is availaBLE. A portion of this loss is made up in the opamp, thus permitting installation of the unit as a unity-gain amplifier with an expansion of 3 db and compression of 12 db. Total conasumption is approximately 4mA. The frequency response of the compressor for various input levels is shown in Fig. 3. A tape recorder using this automatic gain compressor has been successfully used to report events from the quiet of an empty hall to the noisycockit of a small private plane.
The audio compressor or a unity-gain amplifier having an expansion of 3 db and a compression of 12 db around an average level of approximately 45 db below 1 volt at an impedance of 100.000 ohms. The compressor is inserted after the microphone amplifier. The incoming audio signal is amplified by U1a and applied to the diode compressor through C1. The diode compressor is essentially an L-pad attenuator, with R1 forming one leg and diode D3 for the other leg. Diode D1 rectifies the audio signal and applies the resultant DC voltage through R2 to diode D3. The impedance of D3 varies almost logarithmically in inverse proportion to the DC voltage across it. Diode D2 protects filter capacitor C2 from any reverse polarity switching transients that may be applied from the output. The curves of Fig-2 show that about 15 db attenuation is available. A portion of this loss is made up in the opamp, thus permitting installation of the unit as a unity-gain amplifier with an expansion of 3 db and compression of 12 db. Total consumption is approximately 4mA. The frequency response of the compressor for various input levels is shown in Fig. 3. A tape recorder using this automatic gain compressor has been successfully used to report events from the quiet of an empty hall to the noisy cockpit of a small private plane.
volume-compressor
The audio compressor or a unity-gain amplifier having an expansion of 3 db and a compression of 12 db around an average level of approximately 45 db below 1 volt at an impedance of 100.000 ohms. The compressor is inserted after the microphone amplifier. The incoming audio signal is amplified by U1a and applied to the diode compressor through C1. The diode compressor is essentially an L-pad attenuator, with R1 forming one leg and diode D3 for the other leg. Diode D1 rectifieds the audio signal and applies the resultant DC voltage through R2 to diode D3. The impedance of D3 varies almost logarithmically in inverse porportion to the DC voltage across it. Diode D2 protects filter capacitor C2 from any reverse polarity switching transients that may be applied from the output. The curves of Fig-2 show that about 15 deb attenuation is availaBLE. A portion of this loss is made up in the opamp, thus permitting installation of the unit as a unity-gain amplifier with an expansion of 3 db and compression of 12 db. Total conasumption is approximately 4mA. The frequency response of the compressor for various input levels is shown in Fig. 3. A tape recorder using this automatic gain compressor has been successfully used to report events from the quiet of an empty hall to the noisycockit of a small private plane.
The audio compressor or a unity-gain amplifier having an expansion of 3 db and a compression of 12 db around an average level of approximately 45 db below 1 volt at an impedance of 100.000 ohms. The compressor is inserted after the microphone amplifier. The incoming audio signal is amplified by U1a and applied to the diode compressor through C1. The diode compressor is essentially an L-pad attenuator, with R1 forming one leg and diode D3 for the other leg. Diode D1 rectifies the audio signal and applies the resultant DC voltage through R2 to diode D3. The impedance of D3 varies almost logarithmically in inverse proportion to the DC voltage across it. Diode D2 protects filter capacitor C2 from any reverse polarity switching transients that may be applied from the output. The curves of Fig-2 show that about 15 db attenuation is available. A portion of this loss is made up in the opamp, thus permitting installation of the unit as a unity-gain amplifier with an expansion of 3 db and compression of 12 db. Total consumption is approximately 4mA. The frequency response of the compressor for various input levels is shown in Fig. 3. A tape recorder using this automatic gain compressor has been successfully used to report events from the quiet of an empty hall to the noisy cockpit of a small private plane.