Voltage regulator compensating for voltage drop along conductors between regulator output and load

摘要

An automatic voltage compensation circuit in a voltage regulator compensates the output voltage for a voltage drop along lines leading to a remote load. A load capacitor is connected across the load for providing a low impedance across the load during a test phase of the regulator. In one embodiment, during the test phase, the load current is changed up or down a small percentage (e.g., 10%). As a result, the regulator voltage changes due only to the line resistance since the load is bypassed by the load capacitor. The voltage drop at full load current is then derived by detecting the change in regulator output voltage (a fractional voltage drop) and multiplying it. The normal mode is resumed, and the derived voltage drop is added to the regulator output by either compensating the feedback loop or by adding the voltage drop to the output of the regulator.

主权项

1. A method for compensating a voltage regulator output for a voltage drop along one or more conductors conducting current between one or more output terminals of the regulator and a load comprising:
operating the regulator in a first mode of operation to output, at the one or more output terminals of the regulator, a regulated first voltage at a first current drawn by the load; operating the regulator in a second mode of operation by temporarily changing the output of the regulator to cause the regulator to output a second voltage and second current; detecting a difference between at least the first voltage and the second voltage, or between the first current and the second current, to determine a first signal corresponding to a fractional voltage drop along the one or more conductors between the regulator and the load; computing, by using the first signal, a compensation voltage substantially corresponding to a full voltage drop along the one or more conductors when the regulator operates in the first mode of operation; and operating the regulator in the first mode while using the compensation voltage to compensate the output voltage of the regulator for the full voltage drop.