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. 05, 2002
Filed:
Aug. 29, 2000
Dennis M. Rippelmeyer, Waterloo, IL (US);
Emerson Electric Co., St. Louis, MO (US);
Abstract
An ignitor controller and method of providing the same triggers an ignitor switch of a gas appliance, such as a furnace, subsequent to the zero-crossing of the line voltage, but before the voltage exceeds +/−five volts. This effectively reduces EMI levels caused by the constant triggering of AC line voltage to the ignitor switch after +/−five volts, which constant triggering is needed to properly operate ignitors (e.g., silicon nitride ignitors) in electronic ignition systems. The controller includes a voltage detector circuit (i.e., a two transistor circuit), a series switch (i.e., a darlington array) and an energy storage device (i.e., a capacitor), which trigger the ignitor switch (e.g., a triac) sufficiently close to the line voltage zero-crossing to reduce line conducted interference.