Low battery indicator

• US 4,622,544 A
• Filed: 05/13/1985
• Issued: 11/11/1986
• Est. Priority Date: 05/13/1985
• Status: Expired due to Term

• Current Assignee: Lifeline Systems Inc (Koninklijke Philips N.V.)
• Original Assignee: Lifeline Systems Inc (Koninklijke Philips N.V.)
• Inventors: Bially, Theodore, Ditz, Marc W.
• Primary Examiner(s): Rowland, James L.
• Assistant Examiner(s): Myer, Daniel
• Application Number:
  US06/733,713
• Time in Patent Office: 547 Days
• Field of Search: 340/636, 340/573, 340/572, 340/286 M, 340/539, 179/5 R, 320/48, 455/127
• US Class Current: 340/636.1
• 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
• CPC Class Codes: G08B 29/181 due to failing power supply

Abstract

An emergency response system in which the low battery condition of a wireless help unit is automatically detected and indicated at a receiver. The help unit provides, as part of the transmitted signal, a signal indication of battery condition. The received signal is decoded and, upon detection of a low battery signal indication, a visual and/or audible output indication denotes this condition. The low battery indication at the receiver remains on until a transmission is received from the help unit when containing a fresh battery replacement.

Claims

1. An emergency response system comprising:

a help unit for transmitting a signal to a receiver in response to manual actuation of the unit, the signal containing data identifying the unit and data signifying the condition of the unit battery;

a receiver including;

means for receiving the signal transmitted from the help unit to set timer means upon detection of a valid code from the help unit;

timer means providing an output signal defining a reset interval;

an indicator operative in response to the output signal from the timer means operative to signify the reset interval;

latch means providing an output signal to an indicator which provides an output indication of low battery condition;

means operative in response to the received signal from the help unit to set the latch means upon detection of low battery data in the received signal;

output means triggered upon the cessation of the output signal from the timer means to cause an emergency signal; and

means for resetting the timer means during the reset interval, the low battery latch means remaining latched until receipt of a transmitted signal from the help unit containing no low battery data.

2. An emergency system comprising:

a help unit for transmitting a signal to a receiver in response to manual actuation of the unit, the signal containing data identifying the unit and data signifying the condition of the unit battery;

a receiver including;

first means operative upon receipt of the signal transmitted from the help unit to provide a reset interval upon detection of a valid code from the help unit;

indicator means providing an output indication of low battery condition;

second means operative in response to the received signal from the help unit to energize the indicator means upon detected of low battery data in the received signal;

output means operative upon termination of the reset interval to cause an emergency output; and

means for resetting the first means during the reset interval, the second means remaining operative to energize the indicator means until a transmitted signal from the help unit is received signifying a fresh battery.

3. The system of claim 2 in which the first means includes timer means defining the reset interval.

4. The system of claim 3 in which the second means includes:

latch means set in response to the received signal from the help unit containing low battery data; and

gate means operative in response to a signal from the latch means to energize the indicator means to provide an output indication of low battery condition.

5. The system of claim 4 wherein the output means includes:

second latch means operative upon termination of the reset interval to provide an output signal; and

relay means operative in response to the output signal to cause an emergency signal.

6. The system of claim 5 wherein the means for resetting includes a manually operable reset switch.

7. The system of claim 6 wherein the indicator means includes:

a lamp; and

means for causing the lamp to flash in the presence of a low battery signal from the second means.

8. The system of claim 7 including an output indicator providing an output indication of an emergency output provided by the output means.

9. For use in an emergency response system in which a wireless help unit transmits a signal to a receiver for initiating an emergency signal after a predetermined time interval, means in the receiver for denoting a low battery condition for a battery in the help unit, said means comprising:

means for deriving from the signal transmitted by the help unit data signifying the condition of the battery;

means operative upon detection of low battery data to provide an output indication of low battery condition;

means for resetting said operative means only after receipt of a signal from the help unit containing data signifying a fresh battery.