EMERGENCY LIGHTING SYSTEM

• US 3,819,980 A
• Filed: 03/16/1972
• Issued: 06/25/1974
• Est. Priority Date: 03/16/1972
• Status: Expired due to Term

• Current Assignee: Gates Energy Products, Inc. (Schneider Electric SE)
• Original Assignee: Ferdinand H. Mullersman
• Inventors: Mullersman, Ferdinand H.
• Primary Examiner(s): Saalbach, Herman Karl
• Assistant Examiner(s): Mullins, James B.
• Application Number:
  US05/235,371
• Time in Patent Office: 831 Days
• Field of Search: 315/86,87,129,130,135,136,160,161,165,171,173 307/66
• US Class Current: 315/86
• CPC Class Codes: H02J 9/02 in which an auxiliary distribution system and its associated lamps are brought into service

Abstract

An emergency lighting system is provided for rapidly switching a battery into a load circuit in the event AC power on a main line is lost. A first rectifier normally supplied a first charging voltage from the AC power to the battery and a second rectifier supplies a second voltage to a monitoring circuit which keeps the battery switched out of the load circuit until the AC power is lost. In one embodiment where the load is a lamp or lamps the load is normally operating at below rated AC voltage of the lamp for longer life. When the AC power fails, the battery provides sufficient power to the lamp or lamps to provide approximately the same light output. In another embodiment the load is intermittently supplied with battery voltage upon AC power failure to prolong the battery life and to attract attention to the power failure.

Claims

1. An emergency lighting system comprising:

a. first diode means for supplying a first rectified voltage from an AC source;

b. second diode means for supplying a second rectified voltage from said AC source;

c. a common line;

d. a battery having a first terminal connected to receive said first rectified voltage and having a second terminal connected to said common line;

e. a first transistor having an emitter, collector and base, said emitter being connected to said first terminal of said battery;

f. a first load connected between the collector of said transistor and said common line;

g. a capacitor and a resistor connected at first and second common junctions to form a parallel combination, said first junction connected to receive said second rectified voltage and said second junction connected to said common line;

h. a second transistor, said first junction of said combination is connected to the base of said second transistor, the base of said first transistor is connected to the emitter of said second transistor, and the collector of said second transistor is in electrical communication with said first load, said second transistor being biased to a nonconductive state when said combination has a voltage thereacross exceeding a predetermined magnitude and to bias said second transistor to a conductive state when said combination has a voltage thereacross less than said predetermined magnitude; and

i. means for intermittently turning said second transistor on and off after said AC csource ceases to provide power above a predetermined magnitude.

2. The system of claim 1 wherein said turning means is an stable multivibrator.

3. An emergency lighting system comprising:

a. a source of AC power;

b. a first lamp connected in circuit with said AC source;

c. a rechargeable battery connected in parallel with said first lamp and said AC source and having a voltage output approximately equal to the rated voltage of said first lamp;

d. charging means coupling said AC source and said battery to recharge said battery when power is being supplied by said AC source above a predetermined value to said first lamp. e. sensing means for generating a signal in response to power supplied by said AC source;

f. switching means connected in circuit with said first lamp and said battery, said sensing means being coupled to said switching means, said switching means being operable to open and close said circuit connection between said first lamp and said battery when said power from said AC source is above or below, respectively, said predetermined value responsive to the signal being supplied to said switching means by said sensing means;

g. a second lamp connected in series with said AC source; and

h. means to reduce the voltage from said AC source to said first and second lamps below the rated voltage of said lamps sufficiently to reduce the total light output of both lamps to approximate the light output of said first lamp along at its rated voltage to provide long lamp life when power is being supplied from said AC source above said predetermined value and efficient utilization of said battery when power supplied by said AC power source is below said predetermined value.

4. An emergency lighting system comprising:

a. a source of AC power;

b. a transformer having a primary winding connected to said AC source and having a secondary winding;

c. a first load connected in circuit with said secondary winding of said transformer;

d. a rechargeable battery connected in parallel with said load and said secondary winding;

e. charging means coupling said secondary winding and said battery to recharge said battery when said power is being supplied from said AC source above a predetermined value to said load;

f. sensing means for generating a signal in response to power supplied by said AC source;

g. switching means connected in circuit with said load and said battery, said sensing means being coupled to said switching means, said switching means being thereby operable to open and close said connection with said first load and said battery when said power from said AC source is above and below, respectively, said predetermined value responsive to the signal being supplied to said switching means by said sensing means;

h. a first rectification means for half-wave rectification connected to said secondary winding in a first direction to conduct a rectified voltage to said first load during a first series of alternate half cycles of said AC source and not to conduct during a second series of alternate half cycles alternating with said first series of half cycles;

i. a second rectification means for half-wave rectification connected to said secondary winding in a second direction to be blocked during said first series of half cycles when said first rectification means is conductive and to supply a second rectified voltage during said second series of half cycles;

j. a second load connected between said secondary winding and said second rectification means for receiving said second rectified voltage.

5. An emergency lighting system comprising:

a. an AC power source;

b. a transformer having a primary winding connected to said AC source and having a secondary winding;

c. a first load connected in circuit with said secondary winding of said AC source;

d. a first diode means for half-wave rectification connected to secondary winding in a first direction to conduct a first rectified voltage during a first series of alternate half cycles of said AC source and not to conduct during a second series of alternate half cycles alternating with said first series of half cycles;

e. a rechargeable battery coupled to said first diode means to receive said first rectified voltage for charging said battery during said first series of half cycles;

f. sensing means coupled to said secondary winding for generating a signal in response to power being supplied by said AC source;

g. switching means connected in circuit with said first load and said battery, said sensing means being coupled to said switching means, said switching means being operable to open and close said connection with said load and said battery when said power being supplied from said AC source is above and below said predetermined value responsive to the signal being supplied to said switching means by said sensing means;

h. a first rectification means for half-wave rectification coupled to said secondary winding in a first direction to conduct a rectified voltage to said first load during said first series of half cycles of said AC source and not to conduct during said second series of half cycles;

i. a second rectification means for half-wave rectification connected to said secondary winding in a second direction to be blocked during said first series of half cycles of said AC source and to supply a rectified voltage during said second series of half cycles;

j. a second load coupled to said second rectification means for receiving said rectified voltage of said second rectification means;

k. a third rectification means for half-wave rectification coupled to said secondary winding in a second direction to be blocked during one of said first and second series of half cycles of said AC source and to supply a rectified voltage during the other of said first and second series of half cycles; and

l. a pilot light coupled to said third rectification means for receiving said rectified voltage of said third rectification means.

6. An emergency lighting system comprising:

a. an AC power source;

b. a transformer having a primary winding connected to said AC source and having a secondary winding with first and second ends and an intermediate tap;

c. a first diode means connected to said first end for generating a first rectified voltage from said AC source;

d. a second diode means connected to said tap for supplying a second rectified voltage from said AC source;

e. a common line connected to said second end;

f. a battery having a first terminal connected to receive said first rectified voltage and having a terminal connected to said common line;

g. a first transistor having an emitter, collector and base, said emitter being connected to said first terminal of said battery;

h. a first load connected between the collector of said transistor and said common line;

i. a capacitor and a resistor connected at first and second common junctions to form a parallel combination, said first common junction connected to receive said second rectified voltage and said second junction connected to said common line;

j. means coupling the first junction of said combination and the base of said first transistor to bias said transistor to a nonconductive state when said combination has a voltage thereacross exceeding a predetermined magnitude and to bias said transistor to a conductive state when said combination has a voltage thereacross less than said predetermined magnitude;

k. a third diode means for half-wave rectification connected to said tap in a first direction to conduct a third rectified voltage to said first load during positive half cycles of said AC source and not to conduct during negative half cycles therebetween, said third rectified voltage being less than said first rectified voltage;

l. a fourth diode means for half-wave rectification connecTed to said tap in a second direction to be blocked during said positive half cycles of said AC source and to supply a fourth rectified voltage during said negative half cycles therebetween; and

m. a second load connected between said common line in said fourth diode means for receiving said fourth rectified voltage.

7. An emergency lighting system comprising:

a. an AC power source;

b. a transformer having a primary winding connected to said AC source and having a secondary winding with first and second ends and an intermediate tap;

c. a first diode means for half-wave rectification connected to said AC source in a first direction to conduct a first rectified voltage during positive half cycles of said AC source and to not conduct during negative half cycles therebetween;

d. a second diode means connected to said tap for supplying a second rectified voltage from said AC source;

e. a common line connected to said second end;

f. a battery having a first terminal connected to receive said first rectified voltage and having a terminal connected to said common line;

g. a first transistor having an emitter, collector and base, said emitter being connected to said first terminal of said battery;

h. a first load connected between the collector of said transistor and said common line;

i. a capacitor and a resistor connected at first and second common junctions to form a parallel combination, said first junction of said combination connected to receive said second rectified voltage and said second junction connected to said common line;

j. means coupling the first junction of said combination and the base of said first transistor to bias said transistor to a nonconductive state when said combination has a voltage thereacross exceeding a predetermined magnitude and to bias said transistor to a conductive state when said combination has a voltage thereacross less than said predetermined magnitude;

k. a third diode means for half-wave rectification connected to said tap in a first direction to conduct a third rectified voltage to said first load during positive half cycles of said AC source and not to conduct during negative half cycles therebetween, said third rectified voltage being less than said first rectified voltage;

l. a fourth diode means for half-wave rectification connected to said tap in a second direction to be blocked during said positive half cycles of said AC source and to supply a fourth rectified voltage during said negative half cycles therebetween;

m. a second load connected between said common line in said fourth diode means for receiving said fourth rectified voltage;

n. a fifth diode means for half-wave rectification connected to said AC source in a second direction to be blocked during said positive half cycles of said AC source and to supply a fifth rectified voltage during said negative half cycles therebetween; and

o. a pilot light connected between said common line and said fifth diode means for receiving said fifth rectified voltage.

8. An emergency lighting system comprising:

a. a source of AC power;

b. a first load connected in circuit with said AC source;

c. a rechargeable battery connected in parallel with said load and said AC source;

d. charging means coupling said AC source and said battery to recharge said battery when power is being supplied from said AC source above a predetermined value to said load;

e. sensing means coupled to said AC source for generating a signal in response to power supplied by said AC source;

f. switching means connected in circuit with said load and said battery, said sensing means being coupled to said switching means, said switching means being operable to open and close said connection with said load and said battery when said power from said AC source is above and below, respectively, said predetermined value responsive to the signal being supplied to said switching means by said sensing means;

g. control means coupled to said switching means and said battery having conductive and non-conductive modes, said control means being conductive when said battery voltage is above a predetermined level and being non-conductive when said battery voltage falls below said predetermined level.

9. The system of claim 8 wherein said control means is a zener diode.