Method and arrangement for advising when radio pager battery requires replacement

• US 5,424,721 A
• Filed: 03/30/1992
• Issued: 06/13/1995
• Est. Priority Date: 03/30/1991
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Asai, Takayuki
• Primary Examiner(s): Hofsass, Jeffery A.
• Application Number:
  US07/859,971
• Time in Patent Office: 1,170 Days
• Field of Search: 340/636, 340/632, 340/825.44, 340/309.15, 455/38.3, 320/48
• US Class Current: 340/636.15
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm

Abstract

In order to obviate the tendency for batteries to be changed at an overly early timing, the battery voltage is monitored and a first alarm is issued when the battery voltage drops below a predetermined level. The issuance of the first alarm sets a timer which times a predetermined period and issues a second alarm upon the expiration thereof. The length of the predetermined period may be adjusted by the user and the time from the issuance of the first alarm may be shown on a display upon demand.

Claims

1. A portable battery operated radio pager, comprising:

means for comparing the voltage level of a battery with a predetermined voltage level and for detecting when the battery voltage falls below the predetermined voltage level;

means responsive to an initial detection of the voltage falling below the predetermined voltage level for issuing a first alarm signal;

timer means responsive to the issuance of the first alarm for generating a second alarm signal at a predetermined time period after the issuance of the first alarm signal, wherein said timer means counts up from the issuance of the first alarm signal and issues the second alarm signal upon a predetermined count being reached;

display means; and

control means operatively connected to said display means and said timer means, said control means prior to the generation of the second alarm signal, being responsive to a manually generated signal for inducing the count of the timer means to be displayed on the display.