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:
Apr. 13, 1999
Filed:
Nov. 12, 1996
Kim Irwin McCavit, St. Joseph, MI (US);
Roger Donn Bentley, Coloma, MI (US);
Heath Company, Benton Harbor, MI (US);
Abstract
A doorbell circuit detects when one of a plurality of doorbell switches is depressed and provides an audible indication of the particular doorbell switch depressed. The doorbell circuit includes a detector circuit which will function properly with the diode, normally connected in parallel across one of the doorbell switches, connected with either polarity. A power supply is developed for the detector circuit from the doorbell transformer by way of the diode connected in parallel across one of the doorbell switches. The detector circuit includes one or more full-wave rectifiers, which provide a positive DC output signal irrespective of the polarity of the diode connected in parallel across the doorbell switch. Each of the doorbell switches is connected to an amplifier, which, in turn, is connected to a comparator. During conditions when none of the doorbell switches are depressed, the output level of the amplifier will be lower than the threshold level for the comparator to prevent an audible indication from being generated. Once one of the doorbell switches is depressed the amplifier will generate an output signal that is greater than the threshold value for the comparator to cause an audible indication to be generated.