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:
Jan. 01, 1980
Filed:
Dec. 30, 1976
Edward L Ehmke, Margate, FL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A battery saver circuit for a tone coded personalized radio pager device or the like is described which includes a switchable frequency tone filter to detect a predetermined sequence of tones. One of several alert signals is generated when the correct sequential tone code of the device has been detected. Power is periodically applied to a receiver by a power supply circuit and a control circuit. The first code tone is sampled three times to protect against false identification of this tone. After this first (preamble) tone has been validated, power is supplied for an additional duration of time and the filter is set to detect the next code tone. Once the second code tone has been detected, if the next code tone is not detected within a predetermined time window, the control circuit resets the switchable filter to again search for the second tone of the code. By resetting the filter to detect the second tone, it is possible to condense the broadcast time required for a string of coded messages.