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:
Oct. 21, 1997
Filed:
Jul. 29, 1994
Thomas G Xydis, Ann Arbor, MI (US);
Dimango Products, Brighton, MI (US);
Abstract
A wireless audible indication system comprising a transmitter and a receiver. An embodiment of the transmitter includes a modulator formed by a microprocessor and a radio frequency oscillator. The modulation format employed is selectable by the user using severable jumper wires. A battery status circuit is included which verifies the status of a battery within the transmitter. The modulator transmits a low battery bit to the receiver in order to alert the user of a weak transmitter battery. An embodiment of the receiver includes a superregenerative detector which produces an intermediate signal upon receiving a radio frequency signal. A signal processing circuit, which includes an active peak detector stage and a discrete comparator stage, is used to process the intermediate signal. A microprocessor controls a sound generator circuit in response to the processed intermediate signal. The microprocessor, which normally operates in an inactive mode, is awaken using a wake-up circuit upon reception of the radio frequency signal. A battery status circuit is included to verify the status of a battery within the receiver. Embodiments of the transmitter and receiver employ a pulse position modulation scheme.