Device and method for saturation prevention by transfer function modulation associated with conditioning of electrical current or voltage

A signal conditioning circuit, comprising:

• an input node to receive an input signal;
• an output node;
• a forward module coupled between the input node and the output node, the forward module being configured to amplify and invert the input signal and to present a forward output signal to the output node, the forward output signal being an analogue of the input signal;
• and
• a reverse module coupled in anti-parallel with the forward module between the output node and the input node to receive the forward output signal as a reverse input signal and to present a reverse output signal to the input node,
• wherein the reverse module is configured such that the reverse module does not present the reverse output signal to the input node until the forward output signal exceeds a predetermined magnitude based on a linear operating voltage range of the forward module, and
• wherein the forward module comprises a plurality of amplifiers and passive elements including a forward first amplifier and a forward last amplifier configured to have an inverting forward gain defined as a ratio of magnitudes of the forward output signal to the input signal, and wherein an input of the forward first amplifier is coupled to the input node and an output of the forward last amplifier is coupled to the output node.

A method of conditioning a signal, the method comprising:

• receiving a forward input electrical signal at a forward input of a forward module, and outputting a forward output electrical signal at a forward output of the forward module, the forward module being configured to have a substantially instantaneous response and an inverting forward gain defined as a ratio of magnitudes of forward output electrical signals to forward input electrical signals;
• receiving the forward output electrical signal at a reverse input of a reverse module, and outputting a reverse output electrical signal at a reverse output of the reverse module, the reverse module being configured in anti-parallel with the forward module by coupling the reverse input to the forward output and by coupling the reverse output to an input summation module coupled to the forward input, and to have a substantially instantaneous response and a non-inverting reverse gain defined as a ratio of magnitudes of reverse output electrical signals to reverse input electrical signals;
• and
• summing an input electrical signal, received from a source of the input electrical signal at a first sum input of the input summation module, with the reverse output electrical signal received at a second sum input of the input summation module to produce the forward input electrical signal at a total sum output of the input summation module coupled to the forward input of the forward module,
• wherein the forward output electrical signal represents an analogue of the forward input electrical signal multiplied by the inverting forward gain when a magnitude of the forward output electrical signal is within a predetermined region of a linear operating range of the forward module.

A method of conditioning a signal, the method comprising:

• receiving an input signal at an input node;
• amplifying and inverting the input signal, through a forward module coupled between the input node and an output node, to present a forward output signal at the output node, the forward output signal being an analogue of the input signal;
• and
• receiving the forward output signal as a reverse input signal at a reverse module coupled in anti-parallel with the forward module between the output node and the input node, and presenting a reverse output signal from the reverse module to the input node when the forward output signal exceeds a predetermined magnitude based on a linear operating range of the forward module,
• wherein the forward module comprises a plurality of amplifiers and passive elements including a forward first amplifier and a forward last amplifier configured to have an inverting forward gain defined as a ratio of magnitudes of the forward output signal to the input signal when the forward output signal is within the predetermined magnitude based on the linear operating range of the forward module, and wherein an input of the forward first amplifier is coupled to the input node and an output of the forward last amplifier is coupled to the output node, and
• wherein the reverse module comprises a plurality of amplifiers and passive elements including a reverse first amplifier and a reverse last amplifier to provide a non-inverting reverse gain defined as a ratio of magnitudes of the reverse output signal to the reverse input signal, wherein an input of the reverse first amplifier is coupled to the output node.

A method of conditioning a signal, the method comprising:

• receiving an input signal at an input node;
• amplifying and inverting the input signal, through a forward module coupled between the input node and an output node, to present a forward output signal at the output node, the forward output signal being an analogue of the input signal;
• and
• receiving the forward output signal as a reverse input signal at a reverse module coupled in anti-parallel with the forward module between the output node and the input node, and presenting a reverse output signal from the reverse module to the input node when the forward output signal exceeds a predetermined magnitude based on a linear operating range of the forward module,
• wherein the forward module comprises a plurality of amplifiers and passive elements including a forward first amplifier and a forward last amplifier configured to have a non-inverting forward gain defined as a ratio of magnitudes of the forward output signal to the input signal when the forward output signal is within the predetermined magnitude based on the linear operating range of the forward module, and wherein an input of the forward first amplifier is coupled to the input node and an output of the forward last amplifier is coupled to the output node, and
• wherein the reverse module comprises a plurality of amplifiers and passive elements including a reverse first amplifier and a reverse last amplifier to provide an inverting reverse gain defined as a ratio of magnitudes of the reverse output signal to the reverse input signal, wherein an input of the reverse first amplifier is coupled to the output node.

A signal conditioning circuit, comprising:

• a forward module having a forward input to receive a forward input electrical signal and a forward output to output a forward output electrical signal, the forward module being configured to have a substantially instantaneous response and an inverting forward gain defined as a ratio of magnitudes of forward output electrical signals to forward input electrical signals;
• an input summation module including a first sum input coupled to a source of an input electrical signal, a second sum input, and a total sum output coupled to the forward input of the forward module to produce the forward input electrical signal;
• and
• a reverse module including a reverse input to receive a reverse input electrical signal and a reverse output to output a reverse output electrical signal, the reverse module being configured in anti-parallel with the forward module by coupling the reverse input to the forward output and by coupling the reverse output to the second sum input, and to have a substantially instantaneous response and a non-inverting reverse gain defined as a ratio of magnitudes of reverse output electrical signals to reverse input electrical signals,
• wherein the forward output electrical signal represents an analogue of the forward input electrical signal multiplied by the inverting forward gain when a magnitude of the forward output electrical signal is within a predetermined region of a linear operating range of the forward module, and
• wherein the reverse module comprises a plurality of N reverse modules to produce N reverse output electrical signals such that the total sum output is a summation of N+1 signal values, being the N reverse output electrical signals summed with the input electrical signal from the source to form the forward input electrical signal.

A signal conditioning circuit, comprising:

• an input node to receive an input signal;
• an output node;
• a forward module coupled between the input node and the output node, the forward module being configured to amplify and invert the input signal and to present a forward output signal to the output node, the forward output signal being an analogue of the input signal;
• and
• a reverse module coupled in anti-parallel with the forward module between the output node and the input node to receive the forward output signal as a reverse input signal and to present a reverse output signal to the input node,
• wherein the reverse module is configured such that the reverse module does not present the reverse output signal to the input node until the forward output signal exceeds a predetermined magnitude based on a linear operating voltage range of the forward module, and
• wherein a root of the mean of a squared waveform voltage amplitude of a sine waveform fundamental of the input signal is calculated from a zero-volts crossing slope of the sine waveform fundamental, in engineering units of volts per seconds, by dividing the zero-volts crossing slope by a product of the square root of the numeral 2, the numeral 2, pi, and an alternating frequency of the sine waveform fundamental in engineering units of Hertz.

A signal conditioning circuit, comprising:

• an input node to receive an input signal;
• an output node;
• a forward module coupled between the input node and the output node, the forward module being configured to amplify and invert the input signal and to present a forward output signal to the output node, the forward output signal being an analogue of the input signal;
• a reverse module coupled in anti-parallel with the forward module between the output node and the input node to receive the forward output signal as a reverse input signal and to present a reverse output signal to the input node;
• and
• an isolated DC power supply that is isolated from the input signal such that the input node and a system zero-volt common may be coupled in series at any point along a circuit supplying the input signal,
• wherein the reverse module is configured such that the reverse module does not present the reverse output signal to the input node until the forward output signal exceeds a predetermined magnitude based on a linear operating voltage range of the forward module.

A signal conditioning circuit, comprising:

• an input node to receive an input signal;
• an output node;
• a forward module coupled between the input node and the output node, the forward module being configured to amplify and invert the input signal and to present a forward output signal to the output node, the forward output signal being an analogue of the input signal;
• and
• a reverse module coupled in anti-parallel with the forward module between the output node and the input node to receive the forward output signal as a reverse input signal and to present a reverse output signal to the input node,
• wherein the reverse module is configured such that the reverse module does not present the reverse output signal to the input node until the forward output signal exceeds a predetermined magnitude based on a linear operating voltage range of the forward module,
• wherein the reverse module comprises a plurality of amplifiers and passive elements including a reverse first amplifier and a reverse last amplifier to provide a non-inverting reverse gain defined as a ratio of magnitudes of the reverse output signal to the reverse input signal, wherein an input of the reverse first amplifier is coupled to the output node,
• wherein the reverse module further comprises a reverse impedance coupled in series between an output of the reverse last amplifier and the input node, and
• wherein the reverse impedance comprises:
• a plurality of impedances connected in series to form a fixed impedance series;
• and
• an anti-parallel diode pair coupled between the input node and the fixed impedance series such that when the forward output signal does not exceed the predetermined magnitude, a total noise and offset voltage generated by the reverse module is substantially prevented from producing a noise and offset current to the input node.

A signal conditioning circuit, comprising:

• an input node to receive an input signal;
• an output node;
• a forward module coupled between the input node and the output node, the forward module being configured to amplify and invert the input signal and to present a forward output signal to the output node, the forward output signal being an analogue of the input signal;
• and
• a reverse module coupled in anti-parallel with the forward module between the output node and the input node to receive the forward output signal as a reverse input signal and to present a reverse output signal to the input node,
• wherein the reverse module is configured such that the reverse module does not present the reverse output signal to the input node until the forward output signal exceeds a predetermined magnitude based on a linear operating voltage range of the forward module,
• wherein the reverse module comprises a plurality of amplifiers and passive elements including a reverse first amplifier and a reverse last amplifier to provide a non-inverting reverse gain defined as a ratio of magnitudes of the reverse output signal to the reverse input signal, wherein an input of the reverse first amplifier is coupled to the output node,
• wherein the reverse module further comprises a reverse impedance coupled in series between an output of the reverse last amplifier and the input node, and
• wherein the reverse first amplifier includes a positive input, a negative input, and a local voltage output with a second linear operating voltage range configured such that the positive input is coupled to a system zero-volt common.

A signal conditioning circuit, comprising:

• an input node to receive an input signal;
• an output node;
• a forward module coupled between the input node and the output node, the forward module being configured to amplify and invert the input signal and to present a forward output signal to the output node, the forward output signal being an analogue of the input signal;
• and
• a reverse module coupled in anti-parallel with the forward module between the output node and the input node to receive the forward output signal as a reverse input signal and to present a reverse output signal to the input node,
• wherein the reverse module is configured such that the reverse module does not present the reverse output signal to the input node until the forward output signal exceeds a predetermined magnitude based on a linear operating voltage range of the forward module,
• wherein the reverse module comprises a plurality of amplifiers and passive elements including a reverse first amplifier and a reverse last amplifier to provide a non-inverting reverse gain defined as a ratio of magnitudes of the reverse output signal to the reverse input signal, wherein an input of the reverse first amplifier is coupled to the output node,
• wherein the reverse module further comprises a reverse impedance coupled in series between an output of the reverse last amplifier and the input node,
• wherein the forward module further comprises a feedback impedance coupled in parallel with the plurality of amplifiers and passive elements between the input node and the output node,
• wherein the reverse impedance is smaller than the feedback impedance of the forward module,
• wherein the reverse impedance converts a reverse output voltage of the reverse last amplifier to a reverse output signal presented to the input node,
• wherein the reverse output signal combines with the input signal to form a net forward input signal to which a transfer function of the forward module is applied to produce the forward output signal,
• wherein the input signal is an input current, the forward output signal is a forward output voltage, the reverse output signal is a reverse output current, the net forward input signal is a net forward input current, and the transfer function is a transimpedance of the forward module, and
• wherein the forward output voltage is the net forward input current multiplied by the transimpedance of the forward module.