Emergency light circuit for mercury vapor lamps

Claim 2

A lighting circuit, comprising, a. input lines providing a primary source of power; b. a primary lighting circuit including electrical discharge lamp means having different energy demands during hot starting, cold starting and normal operating periods; c. a storage battery; d. charging means coupled to said input lines and adapted to be selectively coupled to charge said battery; e. charge control means responsive to the substantially charged condition of said battery to prevent overcharge thereof by said charging means; f. sensing means responsive to an interruption in the operation of said primary lighting circuit; g. a secondary lighting circuit; h. switching means actuated by said sensing means to connect said battery for energizing said secondary lighting circuit; i. and a time delay device for disconnecting said battery from said secondary lighting circuit a predetermined time interval subsequent to its connection thereto, thereby preventing the complete discharge of said battery.

Claim 3

A lighting system comprising, in combination, a. input lines providing a primary source of power; b. a primary lighting circuit including electrical discharge lamp means having different energy demands during hot starting, cold starting and normal operating periods and ballast means for supplying energy for said lamp means during cold starting and normal operating periods; c. a secondary power source; d. a secondary lighting circuit; e. switching means coupled to said secondary lighting circuit and responsive: e1. to a momentary interruption of current in said primary lighting circuit to energize said secondary lighting circuit from said primary power source, and e2. to an extended period of current interruption in said primary lighting circuit to energize said secondary lighting circuit from said secondary power source.

Claim 4

A lighting system comprising, in combination, a. input lines providing a primary source of power; b. a primary lighting circuit including electrical discharge lamp means having different energy demands during hot starting, cold starting and normal operating periods and ballast means for supplying energy for said lamp means during cold starting and normal operating periods; c. a secondary power source; d. a secondary lighting circuit; e. switching means coupled to said secondary lighting circuit and responsive: e1. to a momentary interruption of current in said primary lighting circuit to energize said secondary lighting circuit from said primary power source, and e2. to an extended period of current interruption in said primary lighting circuit to energize said secondary lighting circuit from said secondary power source.

Claim 5

A lighting system according to claim 2 wherein said secondary power source is a battery and wherein said combination further f. battery-charging means supplied by said primary power source and adapted to charge said battery during normal operation of said primary lighting circuit.

Claim 6

A lighting system according to claim 3 further including g. charge control means responsive to the substantially charged condition of said battery to prevent overcharging thereof, h. and discharge control means operative to disconnect said battery from said secondary lighting circuit a predetermined time interval after energization of said secondary lighting circuit from said battery, wheReby complete discharge of said battery is prevented.

Claim 7

A lighting circuit according to claim 4 wherein said discharge control means comprises a heating resistor in circuit with said primary lighting circuit and a thermal switch connected in series with said battery, said switch being operative to close when current flows through said primary lighting circuit to heat said resistor and to open after the heating resistor has cooled due to a loss of current in said primary lighting circuit, the cooling time defining a discharge interval for said battery.

Claim 8

A lighting system comprising, in combination, a. input lines providing a primary source of power; b. a primary electric gaseous discharge device of a type whose starting potential at normal operating temperature is far in excess of its starting potential at room temperature; c. a ballast circuit capable of generating a potential sufficient for starting said device at room temperature and for sustaining normal operation thereof; d. a secondary power source; e. a secondary lighting circuit; f. a light-sensing circuit supplied by said input lines and optically coupled to said discharge device for providing an electrical response to the inoperative condition thereof; and g. switching means controlled by said light-sensing circuit to energize said secondary lighting circuit from said secondary power source upon occurrence of said electrical response.

Claim 9

A lighting system comprising, in combination, a. input lines providing a primary source of power; b. a primary electric gaseous discharge device of a type whose starting potential at normal operating temperature is far in excess of its starting potential at room temperature; c. a ballast circuit capable of generating a potential sufficient for starting said device at room temperature and for sustaining normal operation thereof; d. a secondary power source; e. a secondary lighting circuit; f. a light-sensing circuit supplied by said input lines and optically coupled to said discharge device for providing an electrical response to the inoperative condition thereof; and g. switching means controlled by said light-sensing circuit to energize said secondary lighting circuit from said secondary power source upon occurrence of said electrical response.

Claim 10

A lighting system according to claim 6 wherein said secondary power source is a battery and wherein said combination further comprises, h. a battery-charging circuit supplied by said primary power source and selectively operable to provide both a fast charge and a trickle charge, depending upon the charge condition of said battery.

Claim 11

A lighting system according to claim 7 further including i. discharge control means operative to disconnect said secondary lighting circuit from said battery an interval of time subsequent to an interruption of said primary power source, thereby preventing excessive discharge of said battery.

Claim 12

A lighting system comprising, a. a primary lighting circuit including electrical discharge lamp means having different energy demands during hot starting, cold starting, and normal operating periods and ballast means for supplying said different energy demands during cold starting and normal operating periods; b. a secondary power source; c. a secondary lighting circuit; d. sensing means responsive to an interruption in the operation of said primary lighting circuit; e. switching means selectively interposed in series with said secondary lighting circuit and adopted for actuation by said sensing means to couple said secondary power source to said secondary lighting circuit, energizing said secondary lighting circuit to provide an auxiliary source of illumination; f. charge control means associated with said secondary power source; and g. discharge control means including a time delay device automatically operable in response to the inoperative condition of said primary lighting circuit, said charge and discharge control means being operative to allow cyclical charging and discharging of said secondary power source in controlled amounts in accordance with the normal daily ON-OFF cycle of said primary lighting circuit.

Claim 13

A lighting system comprising, a. a primary lighting circuit including electrical discharge lamp means having different energy demands during hot starting, cold starting, and normal operating periods and ballast means for supplying said different energy demands during cold starting and normal operating periods; b. a secondary power source; c. a secondary lighting circuit; d. sensing means responsive to an interruption in the operation of said primary lighting circuit; e. switching means selectively interposed in series with said secondary lighting circuit and adopted for actuation by said sensing means to couple said secondary power source to said secondary lighting circuit, energizing said secondary lighting circuit to provide an auxiliary source of illumination; f. charge control means associated with said secondary power source; and g. discharge control means including a time delay device automatically operable in response to the inoperative condition of said primary lighting circuit, said charge and discharge control means being operative to allow cyclical charging and discharging of said secondary power source in controlled amounts in accordance with the normal daily ON-OFF cycle of said primary lighting circuit.

Claim 14

In an auxiliary lighting system for use with a primary night-lighting system an auxiliary power supply including, a. a storage battery, b. a charging circuit for selectively charging said battery, c. means controlling the charge rate to said battery in accordance with the charge state of said battery, and d. time delay means automatically rendered operative during inoperativeness of said primary night-lighting system for controlling the discharge period of said battery, said charge and discharge control means being cyclically operable in conjunction with the normal daily ON-OFF cycle of said primary night-lighting system And said charge and discharge of said battery being controlled in predetermined amounts so as to prolong the operating life of said battery.

Claim 15

In an auxiliary lighting system for use with a primary night-lighting system an auxiliary power supply including, a. a storage battery, b. a charging circuit for selectively charging said battery, c. means controlling the charge rate to said battery in accordance with the charge state of said battery, and d. time delay means automatically rendered operative during inoperativeness of said primary night-lighting system for controlling the discharge period of said battery, said charge and discharge control means being cyclically operable in conjunction with the normal daily ON-OFF cycle of said primary night-lighting system And said charge and discharge of said battery being controlled in predetermined amounts so as to prolong the operating life of said battery.

Claim 16

A lighting system comprising, a. input lines providing a primary source of power, b. a primary electric gaseous discharge device whose starting potential at its normal operating temperature is far in excess of the starting potential required at room temperature, c. a ballast circuit capable of supplying a sufficient starting potential when said device is at room temperature, d. a storage battery, e. a battery-charging circuit supplied by said primary power source and operable to provide a fast charging current and a trickle charging current, f. switching means selectively coupling said fast charge current or said trickle charge current to said battery in accordance with the charge state of said battery, g. a light-sensing circuit including a direct current power supply and a photosensitive device optically coupled to said discharge device to provide an electrical response to an interruption of illumination thereof; h. a secondary lighting circuit; i. switching means associated with said sensing circuit for energizing said secondary lighting circuit from said battery upon the occurrence of said electrical response; and j. a time delay relay having a pair of contacts in circuit with said secondary lighting circuit and an energization coil adapted for energization by said primary power source, said contacts being operative to open a predetermined interval after an interruption in said primary source of power so that complete discharge of said battery does not occur.

Claim 17

A lighting system comprising, a. input lines providing a primary source of power, b. a primary electric gaseous discharge device whose starting potential at its normal operating temperature is far in excess of the starting potential required at room temperature, c. a ballast circuit capable of supplying a sufficient starting potential when said device is at room temperature, d. a storage battery, e. a battery-charging circuit supplied by said primary power source and operable to provide a fast charging current and a trickle charging current, f. switching means selectively coupling said fast charge current or said trickle charge current to said battery in accordance with the charge state of said battery, g. a light-sensing circuit including a direct current power supply and a photosensitive device optically coupled to said discharge device to provide an electrical response to an interruption of illumination thereof; h. a secondary lighting circuit; i. switching means associated with said sensing circuit for energizing said secondary lighting circuit from said battery upon the occurrence of said electrical response; and j. a time delay relay having a pair of contacts in circuit with said secondary lighting circuit and an energization coil adapted for energization by said primary power source, said contacts being operative to open a predetermined interval after an interruption in said primary source of power so that complete discharge of said battery does not occur.

Claim 18

In an emergency lighting circuit for use with electrical gaseous discharge lighting systems having a ballast circuit capable of providing a potential sufficient to start gaseous discharge lamps at room temperature but insufficient to start the lamps at their normal operating temperature, the combination comprising, a. input lines providing a primary source of power for said ballast circuit; b. a secondary power source; c. a secondary lighting circuit, and d. switching means coupled to said secondary lighting circuit and responsive: d1. to a momentary interruption of current through said gaseous discharge lamps to energize said secondary lighting circuit from said primary power source, and d2. to an extended period of current interruption in said lamps to energize said secondary lighting circuit from said secondary power source.

Claim 19

In an emergency lighting circuit for use with electrical gaseous discharge lighting systems having a ballast circuit capable of providing a potential sufficient to start gaseous discharge lamps at room temperature but insufficient to start the lamps at their normal operating temperature, the combination comprising, a. input lines providing a primary source of power for said ballast circuit; b. a secondary power source; c. a secondary lighting circuit, and d. switching means coupled to said secondary lighting circuit and responsive: d1. to a momentary interruption of current through said gaseous discharge lamps to energize said secondary lighting circuit from said primary power source, and d2. to an extended period of current interruption in said lamps to energize said secondary lighting circuit from said secondary power source.

Claim 20

The combination in an emergency lighting system according to claim 12 wherein said secondary power source is a battery and wherein said combination further includes; e. a battery-charging circuit, f. charge control means responsive to the substantially charged condition of said battery to prevent overcharging thereof, and g. discharge control means operative to disconnect said battery from said secondary lighting circuit a predetermined time interval after energization of said secondary lighting circuit from said battery, whereby complete discharge of said battery is prevented.