Control circuit and method for a fly-back voltage converter
US7518888B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 2006 |
| Grant date | Apr 14, 2009 |
| Priority date | — |
| Expiry date | May 2, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0038
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a fly-back voltage converter that includes a transformer to transform a primary current to a secondary current and a switch serially coupled to the primary winding to switch the primary current in response to a control signal, a detection signal is produced by comparing the secondary current with two threshold values after the primary current is switched off to trigger the next on-time cycle of the switch. Once the secondary current is detected to be greater than a first threshold value, it is determined that the secondary current has been switched on, and until the secondary current is detected to be lower than a second threshold value, it is determined that the secondary current is to be switched off. The hysteresis range of the threshold values prevents error detection of the secondary current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.