Browse Prior Art Database

Universal Bulkless Power Factor Technology

IP.com Disclosure Number: IPCOM000115483D
Original Publication Date: 1995-May-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Cassidy, BM: AUTHOR [+2]

Abstract

The disclosed circuit as shown in the figure makes it possible for a Bulkless power factor correction AC/DC converter to operate over a full range of AC line voltage from 70 to 269 Volts. There is no overdesign for input capacitors or switching transistors or transformer T1. There is no such circuit available for power factor corrected AC/DC converters as yet in the whole industry.

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Universal Bulkless Power Factor Technology

      The disclosed circuit as shown in the figure makes it possible
for a Bulkless power factor correction AC/DC converter to operate
over a full range of AC line voltage from 70 to 269 Volts.  There is
no overdesign for input capacitors or switching transistors or
transformer T1.  There is no such circuit available for power factor
corrected AC/DC converters as yet in the whole industry.

      VIN is the input AC line voltage applied to a rectifier bridge
consisting of diodes CR1, CR2, CR3 and CR4.  The full wave rectified
voltage appears across the parallel or series combination of
non-polarized capacitors C1 and C2.

      For line voltage from 70-130 volt, switch S1 and S2 are closed
and C1 and C2 are connected in parallel.  Switches S1 and S2 can be
electronic switches which can be closed or opened based on the input
AC line voltage.  When S1 and S2 are closed, transistors Q1 and Q2
are switching in a push pull mode to deliver the right voltage to the
secondary of the transformer.

      For line voltage from 130-269 volt, switch S1 and S2 are opened
and C1 and C2 are connected in series.  Switches S1 and S2 can be
electronic switches that can be closed or opened based on the input
AC line voltage.  When S1 and S2 are open, transistors Q1 and Q2 are
switching in a half bridge mode to deliver an appropriate voltage to
the secondary of the transformer T1.

      The output from the secondary of T1 is...