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:
Mar. 15, 1988
Filed:
Dec. 30, 1983
Daniel R Schroeder, Glen Ellyn, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A two-way radio communications system includes a battery-operated portable unit and a base unit having a receptacle for receiving the portable unit when the portable unit is not in use. A security circuit in each unit allows communication with other units only upon the reception of an address code corresponding to an address code stored in the unit. When the portable unit is seated in the base unit receptacle, the batteries of the portable unit are recharged by current supplied by the base unit. At the same time, the address code of the base unit is entered into the portable unit by encoding circuitry which modulates the battery charging current in accordance with the address code. Circuitry within the portable unit demodulates the charging current to recover the address code for storage in the security circuit of the portable unit. The invention can also be used in systems where data other than address codes must be sent to a unit being charged.