Power supply device and image forming apparatus
US8564983B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 9, 2011 |
| Grant date | Oct 22, 2013 |
| Priority date | — |
| Expiry date | Jan 25, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/33507
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A power supply device includes a transformer including a primary coil, a secondary coil, and a tertiary coil; a switching element connected via the primary coil to a direct-current power supply; a first rectifying-and-smoothing circuit rectifying and smoothing a voltage generated in the secondary coil; a control circuit turning on and off the switching element; a second rectifying-and-smoothing circuit rectifying and smoothing a voltage generated in the third coil to generate a driving voltage for the control circuit; and a starting circuit including a first transistor, a first resistor, and a first capacitor connected in series between the direct-current power supply and a ground, a second transistor connected between the direct-current power supply and the second rectifying-and-smoothing circuit, and a turn-off unit turning off at least the second transistor out of the first transistor and the second transistor when the first capacitor is charged to a predetermined voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.