The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 25, 1986
Filed:
Oct. 05, 1984
P R Chetty, Germantown, MD (US);
Gary Galloway, Marseilles, IL (US);
Pierre Thollot, Rockford, IL (US);
Sundstrand Corporation, Rockford, IL (US);
Abstract
A soft-start circuit for an inverter having a switch which is operated in accordance with the output of an oscillator includes a ramp generator coupled to the oscillator for generating a cycle ramp signal synchronized to and having the same period as the oscillator output, the cycle ramp signal also having an amplitude which periodically increases between first and second levels. Means are included for generating a soft-start signal having an amplitude which increases between the first and second levels, the length of time required for the amplitude of the soft-start signal to increase from the first level to the second level being substantially longer than the period of the cycle ramp signal. Means are coupled to the ramp generator and to the soft-start signal generating means for comparing the two signals to develop a pulse width modulated enable signal having a series of pulses of gradually increasing pulse width. Means are coupled to the comparing means and to the oscillator for gating the oscillator output with the pulse width modulated enable signal to derive switch control signals for the switch in the inverter. The switch is thereby operated at gradually increasing duty cycles immediately following turn on of the inverter.