INSTRUMENT POWER-DISCONNECT ALARM

• US 3,678,491 A
• Filed: 07/20/1970
• Issued: 07/18/1972
• Est. Priority Date: 07/20/1970
• Status: Expired due to Term

• Current Assignee: Warner-Lambert Company (Pfizer Inc.)
• Original Assignee: Christopher C. Day
• Inventors: Day, Christopher C.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Slobasky, Michael
• Application Number:
  US05/056,295
• Time in Patent Office: 729 Days
• Field of Search: 340/253C,248A,384E,280,421 128/2.6A
• US Class Current: 340/654
• CPC Class Codes: G08B 21/08 responsive to the presence of persons in a body of water, e.g. a swimming pool; responsive to an abnormal condition of a body of water
• CPC Class Codes: G08B 21/185 Electrical failure alarms

Abstract

An instrument power-disconnect alarm. Apparatus is disclosed which provides an alarm in the event of inadvertent power disconnection from electronic instrumentation. For normal instrument power turnoff, the alarm is disabled. The present invention is particularly useful in conjunction with instruments used in monitoring, measuring or stimulating bodily function of hospitalized bedridden patients, where accidental power turnoff of a critical electronic instrument could be a matter of life and death.

Claims

1. An electronic instrument capable of being used in an environment having standby personnel and capable of functioning with both electrical inputs from, and electrical outputs to, a human being, said instrument having a connection to an external electrical power source, wherein the improvement comprises:

detecting means for detecting occurrence of inadvertent loss of said connection to said power source, said detecting means comprising a current activated switch arranged to open in response to power transfer to said instrument, and arranged to close in response to said loss;

alarm means responsive to the operation of said detecting means for communicating the resultant power loss to said standby personnel said alarm means comprising (1 ) a storage capacitor arranged to be charged near a predetermined voltage in response to normal operation of said instrument, and (2) primary discharge means including an alarm triggered by discharge of said voltage of said capacitor through said current operated switch for communicating said power loss; and

, secondary discharge means for unnoticably discharging said voltage of said capacitor in response to normal power turnoff of said instrument.

2. Alarm means as recited in claim 1 wherein said alarm is an audio alarm.

3. Alarm means as recited in claim 1 wherein said alarm is a visual alarm.

4. Alarm means as recited in claim 1 wherein said alarm is radio frequency transmitted and received.

5. Alarm means as recited in claim 1 wherein said alarm is a plurality of individual alarms, each being separately located.

6. Alarm means as recited in claim 5 wherein at least part of said plurality of individual alarms are remotely located.