Compensating for cord resistance to maintain constant voltage at the end of a power converter cord
US7869229B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2007 |
| Grant date | Jan 11, 2011 |
| Priority date | — |
| Expiry date | Aug 6, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/33523
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A cord correction circuit in a primary-side-controlled flyback converter compensates for the loss of output voltage caused by the resistance of the charger cord. In one embodiment, a correction voltage is subtracted from a feedback voltage received from a primary-side auxiliary inductor. A pre-amplifier then compares a reference voltage to the corrected feedback voltage. In another embodiment, the correction voltage is summed with the reference voltage, and the pre-amplifier compares the feedback voltage to the corrected reference voltage. The difference between the voltages on the input leads of the pre-amplifier is used to increase the output voltage to compensate for the voltage lost through the charger cord. The flyback converter also has a comparing circuit and a control loop that maintain the peak level of current flowing through the primary inductor of the converter. Adjusting the frequency and pulse width of an inductor switch signal controls the converter output current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.