Browse Prior Art Database

Fault Limiter for Switching Voltage Regulator

IP.com Disclosure Number: IPCOM000042483D
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Riggio, SR: AUTHOR

Abstract

A fault limiter circuit is described for preventing a switching-type voltage regulator from going into either a saturation condition or a cut-off condition. A saturation condition will cause the switching regulator to overheat and destroy itself. A cut-off condition causes a total loss of output power which is undesirable in some systems. Differential amplifier 10, triangle wave generator 11 and comparator 12 produce at the output of comparator 12 a pulse-width modulated signal which controls the switching action in a switching voltage regulator 13 so as to produce a regulated direct current output voltage which is supplied to the load. If the output voltage Vout increases above the desired regulated value, the error voltage Ve produced by the differential amplifier 10 will decrease.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 62% of the total text.

Page 1 of 2

Fault Limiter for Switching Voltage Regulator

A fault limiter circuit is described for preventing a switching-type voltage regulator from going into either a saturation condition or a cut-off condition. A saturation condition will cause the switching regulator to overheat and destroy itself. A cut-off condition causes a total loss of output power which is undesirable in some systems. Differential amplifier 10, triangle wave generator 11 and comparator 12 produce at the output of comparator 12 a pulse-width modulated signal which controls the switching action in a switching voltage regulator 13 so as to produce a regulated direct current output voltage which is supplied to the load. If the output voltage Vout increases above the desired regulated value, the error voltage Ve produced by the differential amplifier 10 will decrease. This causes the "on" time pulse width at the output of comparator 12 to become smaller. By "on" time is meant the primary conduction time in the switching regulator 13. This brings Vout back down to the desired level. Conversely, if the output voltage Vout decreases, the error voltage Ve increases. This increases the "on" time pulse width at the output of comparator 12 to cause the switching regulator 13 to increase the value of Vout. A desirable fault-limiting action is added to the voltage regulator by connecting clamping circuitry to the error voltage feedback path. This clamping circuitry includes resistors R1, R2 and R3 and diodes D1...