Self-correcting amplifier system
OwnerDonald Marvin, John McHardy +1inventors
InventorsDonald Marvin, John McHardy, Kurt Salloux
Life of this patent
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Abstract
DC offsets introduced in battery testing equipment are automatically compensated for using complementary current-mode servo feedback. An op amp receives and amplifies a response signal, while also introducing internal errors manifested in the amplified response signal. A correction circuitry coupled to receive the amplified response signal and comprising a balanced circuit with a positive input correction device and a negative input correction device to remove the DC bias. The correction circuitry further comprises an error sensing device to correct for the internal errors introduced by the op amp.
Claims14
A battery testing device to automatically compensate for DC offsets arising from the battery testing device, comprising:
- an input terminal to receive an excitation response signal comprising a DC bias and an AC response;
- an op amp coupled to receive and to amplify the response signal, the op amp introducing internal errors manifested in the amplified response signal;
- a servo integrator coupled to receive the amplified response signal and to determine the DC bias and a rate of change of the amplified response signal, and in response, to produce a servo feedback signal to compensate for the DC bias;
- a correction circuitry, coupled to receive the servo feedback signal and to output a correction current to the op amp, and to produce the correction current in order to remove the DC bias;
- an error sensing device, coupled to receive the correction current and to output a feedback control signal, to adjust for the internal errors introduced by the correction circuitry;
- and
- an output terminal to output a corrected AC signal.
A method in a battery testing device to automatically compensate for DC offsets arising from the battery testing device, comprising:
- receiving an excitation response signal comprising a DC bias and an AC response;
- amplifying the response signal with an op amp, the op amp introducing internal errors manifested in the amplified response signal;
- determining the DC bias and a rate of change of the amplified response signal to, in response, produce a servo feedback signal that compensates for the DC bias;
- producing a correction current for the op amp from the servo feedback signal in order to remove the DC bias;
- adjusting the correction current for internal errors sensed in the correction circuit with a feedback control signal;
- and
- outputting a corrected response signal.
Dependencies are inferred from the claim text.