US 6,741,124 B2 · Differential gain adjusting amplifier system with selectable electroluminescent differential photocell attenuation

Abstract

An audio attenuator has a differential signal path with photoconductive cells connected to vary signal levels in the circuit. Electroluminescent light sources adjacent to the photoconductive cells direct light onto the photocells. The electroluminescent light sources receive the input audio signal, an output audio signal, or some other signal. The light sources are connected to a differential control with receives an input of the attenuator circuit. The differential control provides a control input to a differential audio amplifier which receives the input audio signal. The varying signal at the control input effects a variation in the gain of the amplifier. A compression or limiting of the input signal results, depending on which signal is connected to the light sources.

Claims14

Dependent claims

A differential gain controlled amplifier, comprising:

an input transformer for receiving an input signal;
a differential control amplifier receiving the input signal from said input transformer, said differential control amplifier having an output;
at least one light source connected to said output of said differential control amplifier, said at least one light source generating illumination energy which varies in intensity in substantially linear relation to said input signal;
at least one photoconductive element optically coupled to said at least one light source;
and
a differential attenuating circuit connected to said at least one photoconductive element, said differential attenuating circuit having outputs from which output signals are available.

3 more elements

A balanced differential network having a gain controlled in response to frequency and amplitude of an audio input signal, comprising:

a constant fixed gain differential amplifier having inputs connected for response to said audio input signal, said differential amplifier having an output which is substantially identical to said audio input signal applied to said inputs;
a set of selectable solid state electroluminescent light sources connected to said output of said differential amplifier to react to frequency and amplitude of a signal from said output of said differential amplifier, said light sources having an output of an intensity which is substantially linearly related to the frequency and amplitude of an output signal;
and
a differential attenuating network connected to receive said audio input signal and generate a differential signal therefrom, said differential attenuating network being connected to said inputs of said differential amplifier to apply said differential signal to said inputs of said differential amplifier so that said differential amplifier responds to variations in frequency and amplitude of said differential signal, said differential attenuating network including at least one photoconductive resistive element that is optically coupled to respond to light from said light sources.

1 more element

Dependencies are inferred from the claim text.

Differential gain adjusting amplifier system with selectable electroluminescent differential photocell attenuation

Life of this patent

Differential gain adjusting amplifier system with selectable electroluminescent differential photocell attenuation

Life of this patent

Abstract

Claims14