Browse Prior Art Database

Control Technique for Magnetic Amplifier Post Regulators

IP.com Disclosure Number: IPCOM000109873D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Miller, GJ: AUTHOR [+2]

Abstract

Disclosed is a magnetic amplifier (magamp) post-regulator circuit that does not need an external bias voltage to provide reset current to the saturable reactors. The benefits of having the reset circuit of a magamp regulator independent of a bias voltage can be appreciated upon examination of the magamp regulator's operation.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 69% of the total text.

Control Technique for Magnetic Amplifier Post Regulators

       Disclosed is a magnetic amplifier (magamp) post-regulator
circuit that does not need an external bias voltage to provide reset
current to the saturable reactors.  The benefits of having the reset
circuit of a magamp regulator independent of a bias voltage can be
appreciated upon examination of the magamp regulator's operation.

      The figure shows a common magamp configuration that uses a
secondary output stage from a conventional push-pull power converter
with saturable inductors in both secondary windings.  The saturable
inductors, act as efficient pulse-width modulating (PWM) switches by
adjusting their voltage blocking characteristics by means of a
control circuit consisting of an error amplifier and a reset current
driver.  The reset current driver is the novelty in this circuit.

      In the positive output voltage application (as shown in the
figure), the reset circuit uses the negative excursion of the
secondary voltage to generate the current required to reset the
saturable inductors.  Q1 translates the positive error amp output
voltage to the negative voltage required on the gate of Q2.  Q2 could
also be a bipolar transistor depending upon whether the user wants a
voltage or current source driver.  The circuit can also be easily
adapted to the negative output voltage situation.

      The major benefit of this control technique is that it is
fail-safe under loss of external...