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Emergency lighting supervisory system

  • US 4,799,039 A
  • Filed: 05/08/1987
  • Issued: 01/17/1989
  • Est. Priority Date: 01/30/1985
  • Status: Expired due to Term
First Claim
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1. An emergency lighting supervisory system for entering emergency mode operation that causes at least one emergency lamp to be energized from emergency battery power upon sensing an emergency condition such as utility power failure comprising:

  • A. a battery for providing emergency power;

    B. a battery charger for maintaining the battery in a fully charged state;

    the battery charger comprising means for providing a constant current charging of the battery upon system installation or after the battery has provided emergency power, thereafter providing an equalization voltage to the battery having a value greater than the nominal charging voltage presented to the battery, wherein this equalization voltage is provided for a set period of time, and thereafter providing a float voltage having a value equal to the nominal charging voltage to the battery, such charging continuing until a transfer to emergency battery power is needed;

    C. at least one lamp to be illuminated by the battery when emergency power is provided;

    D. means, interconnected to the utility power, the battery and the lamp, for sensing the utility power voltage and for initiating the transfer from utility power to battery emergency power when utility power is not present, when the utility power voltage falls below a threshold value, or when self-testing of the emergency lighting system is performed;

    E. means for performing periodic self-testing of emergency lighting supervisory system parameters, said means including1. timer generating means including means for generating outputs which occur on a multi-day basis,2. self-test control means responsive to said timing output for initiating a self-test for a period of time, said means including means for activating the transfer means so as to place the system in a simulated emergency operating mode, and3. means for monitoring and displaying the status of system parameters when the self-test condition is activated, including means for determining current flow through the lamp so as to ascertain if the lamp is operating properly, said current flow means including means for visually annunciating the determination of an improperly operating lamp, means for determining if a battery induced voltage is applied to the lamp so as to determine if transfer of battery power has occurred, said applied voltage determining means including means for visually annunciating the determination of improper transfer of battery power to the lamp, and means for determining if the battery voltage is below a predetermined level indicative of a faulty battery condition, said battery voltage determining means including means for visually annunciating the determination of a faulty battery condition; and

    F. communication means for transfer of the status of the system parameters from the self-test procedure to an interconnected device as well as to provide for initiation of a self-test procedure upon receipt of a request from an interconnected device.

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