Self-oscillation type switching power supply apparatus
US6078508A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1999 |
| Grant date | Jun 20, 2000 |
| Priority date | — |
| Expiry date | Jan 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/33523
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A self-oscillation type switching power supply apparatus comprises: a transformer T having a primary winding N1, a secondary winding N2, and a feedback winding N.sub.B ; a switching transistor Q1 for interrupting a current in said primary winding N1; a controlling transistor Q2 for controlling a positive feedback signal for said switching transistor Q1 from said feedback winding N.sub.B ; a time constant circuit adapted to be charged by a voltage produced in said feedback winding N.sub.B at a predetermined time constant and to give a controlling voltage to said controlling transistor Q.sub.2 ; a light emitting element of a photocoupler provided in a circuit for detecting an output voltage or output current from the secondary of said transformer T; a photodetector of said photocoupler connected to said time constant circuit whereby the time constant of said time constant circuit is changed in dependence on the detection of the output voltage or output current to stabilize the output voltage or output current; and a conducting path provided between an input power-supply voltage supplying section for the primary of said transformer T and a voltage-supplying section for said photodetec…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.