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:
Jul. 18, 1989
Filed:
Nov. 05, 1987
Peter W Vanderhelst, Birmingham, MI (US);
Medar, Inc., Farmington Hills, MI (US);
Abstract
Active snubber structure and method for use with an electronic power inverter to reduce turn off losses in electronic switches in the power inverter. The snubber structure includes a resistor and a capacitor connected in series with each other and in parallel with the load on the power inverter and parallel, inverse connected silicon controlled rectifiers connected in parallel with the resistor for selectively shorting the resistor. In the method of use of the active snubber structure, electrical energy is stored in the capacitor connected in parallel with the load during on time of the inverter and the resistor is shorted immediately prior to the off time of the inverter whereby the capacitor charges substantially to the value of the source of direct current electrical energy during the on time of the inverter and on shorting of the resistor during off time of the inverter, the voltage across the load changes slowly so that the switches of the inverter can transition from on through a resistor like turn off stage, to completely off before there is appreciable voltage across them.