US 4,225,913 AGranted

Self-referencing power converter

AssigneeTexas Instruments Incorporated

InventorWilliam E. Bray

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Abstract

A self-referencing power converter operates at a high frequency with a low loss, light weight ferrite core transformer. The transformer primary is selectively connected across a DC source of rectified AC power to provide energy storage followed by a predetermined time period of disconnect to provide energy transfer by way of transformer flyback. The energy storage cycle begins when the voltage across the primary winding of the transformer does not exceed a predetermined value and the predetermined time period of disconnect has ended. A current sensing circuit senses the current flowing through the primary winding, permitting such current to flow until a power reference is reached. A comparison circuit in the transformer secondary compares a reference voltage with an operating voltage and returns any error voltage to the primary circuit, the error voltage then being used to set the power reference.

Claims13

Dependent claims

A self-referencing power converter for connection to a DC source of power, with a regulation cycle having an energy storage cycle and an energy transfer cycle, comprising:

(a) a transformer having a secondary winding, and a primary winding that is selectively connected across the DC source during the energy storage cycle to permit current flow in one direction, and selectively disconnected during the energy transfer cycle to permit current flow in the other direction in the secondary winding;
(b) power switching means connected to the DC source and to the primary winding, and having control means for permitting the switching means to close, thereby connecting the primary winding across the DC source, and for permitting the switching means to open, thereby disconnecting the primary winding from the DC source;
(c) timing means connected to the control means to permit the switching means to close after it has been open a predetermined period of time;
(d) current sensing means connected to the primary winding for sensing current therethrough, and connected to the control means to permit the power switching means to open when the sensed current reaches the level of a preset power reference;
and
(e) power reference setting means connected to the current sensing means for effectively setting the power reference.

3 more elements

Dependencies are inferred from the claim text.