Blocking oscillator switched mode power supply
US4593347A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1984 |
| Grant date | Jun 3, 1986 |
| Priority date | — |
| Expiry date | Mar 12, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved blocking oscillator switched mode power supply, which is protected against a voltage rise on the primary side of a transformer of the switched mode power supply, which occurs in a no-load operation and could endanger the circuit. In a design of the blocking oscillator switched mode power supply according to the invention, the output of the variable gain amplifier, connected in known manner to an input of the pulse duration modulator (or pulse width modulator) of the control circuit of the blocking oscillator, is connected through an operational amplifier, which serves as comparator and is actuated by an auxiliary voltage to an additional input of the pulse duration modulator. The pulse duration modulator is provided in the usual manner for controlling the base of a switching transistor, forming a connection between one end of the primary side of the transformer and the terminal for the reference potential. Furthermore, for the solution of the problem referred to in a design of the switched mode power supply corresponding to the invention, the output of a pulse processing circuit is connected via a switching circuit or respectively via a capacitor to the input of the var…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.