Fail-safe solid-state emergency lighting power supply and transfer circuit

Claim 2

An automatically activated emergency power supply system for load devices powered by alternating current comprising A. an emergency storage battery, B. a single full-wave rectifier conductively coupled to an alternating current power line normally delivering DC charging potential to said emergency storage battery through a first reverse current blocking device, C. an inverter oscillator conductively connected to the terminals of said battery and incorporating two alternately conductive electronic amplifying devices each having first and second terminals and capable of being biased into a nonconductive mode by the application of DC bias potential between said terminals of each device, D. an ''''off'''' bias line connecting one output side of the fullwave rectifier through second reverse current blocking means to the first terminals of both amplifying devices and thereby delivering biasing potential to said first terminals reLative to said second terminals at all times when said single fullwave rectifier is activated by normal alternating current line power and thereby maintaining both amplifying devices nonconductively biased to maintain the oscillator in a nonoscillating mode, E. said inverter oscillator incorporating an oscillator output transformer with a secondary winding having a first end connected in series with a first high-pass capacitor and having a second capacitor in parallel with said secondary winding and said first capacitor, F. an inductive impedance interposed between the junction of said capacitors and an output terminal tap connectable to a first terminal of the alternating current load, G. and a second terminal tap connected to the second end of said secondary winding, and connectable to a second terminal of the alternating current load, whereby said amplifying devices are both automatically biased to said non-conductive mode via said ''''off'''' bias line during normal operation of the full-wave rectifier, and said ''''off'''' bias is automatically removed upon interruption of power on the alternating current power line, activating the inverter oscillator to supply alternating current to the load device.

Claim 3

An automatically activated emergency power supply system for load devices powered by alternating current comprising A. a single full-wave rectifier connected to be driven by normally available alternating current from a power line, B. a storage battery connected via a first reverse current blocking device across the output of the single full-wave rectifier, C. an inverter oscillator circuit incorporating two transistors having first and second terminals and capable of being biased into a non-conductive mode by a bias potential applied across said terminals, D. an ''''off'''' bias line connecting one output side of the full-wave rectifier through second reverse current blocking means to the first terminals of both transistors and thereby delivering biasing potential to said first terminals relative to said second terminals at all times when said single full-wave rectifier is activated by normal alternating current line power and thereby maintaining both transistors non-conductively biased to maintain the oscillator in a non-oscillating mode, E. said inverter oscillator incorporating an oscillator output transformer having a secondary winding having a first end connected in series with a first high-pass capacitor and having a second capacitor in parallel with said secondary winding and said first capacitor, F. an inductive impedance interposed between the junction of said capacitors and an output terminal tap connectable to a first terminal of the alternating current load, G. and a second terminal tap connected to the second end of said secondary winding, and connectable to a second terminal of the alternating current load, whereby said transistors are both automatically biased to said non-conductive mode via said ''''off'''' bias line during normal operation of the full-wave rectifier, and said ''''off'''' bias is automatically removed upon interruption of power on the alternating current power line, activating the inverter oscillator to supply alternating current to the load device.

Claim 4

An automatically activated emergency power supply system for load devices powered by alternating current comprising A. a single full-wave rectifier connected to be driven by normally available alternating current from a power line, B. a storage battery connected via a first reverse current blocking device across the output of the single full-wave rectifier, C. an inverter oscillator circuit incorporating two transistors having first and second terminals and capable of being biased into a non-conductive mode by a bias potential applied across said terminals, D. an ''''off'''' bias line connecting one output side of the full-wave rectifier through second reverse current blocking means to the first terminals of both transistors and thereby delivering biasing potential to said first terminals relative to said second terminals at all times when said single full-wave rectifier is activated by normal alternating current line power and thereby maintaining both transistors non-conductively biased to maintain the oscillator in a non-oscillating mode, E. said inverter oscillator incorporating an oscillator output transformer having a secondary winding having a first end connected in series with a first high-pass capacitor and having a second capacitor in parallel with said secondary winding and said first capacitor, F. an inductive impedance interposed between the junction of said capacitors and an output terminal tap connectable to a first terminal of the alternating current load, G. and a second terminal tap connected to the second end of said secondary winding, and connectable to a second terminal of the alternating current load, whereby said transistors are both automatically biased to said non-conductive mode via said ''''off'''' bias line during normal operation of the full-wave rectifier, and said ''''off'''' bias is automatically removed upon interruption of power on the alternating current power line, activating the inverter oscillator to supply alternating current to the load device.

Claim 5

An automatically activated emergency power supply system for load devices powered by high frequency alternating current comprising A. a single full-wave rectifier incorporating a smoothing capacitor across its positive and negative DC output terminals driven by normally available alternating current from a power line, B. a storage battery connected across the positive and negative output terminals of the single full-wave rectifier, with a first reverse current blocking diode being interposed between the positive terminal of the emergency storage battery and the smoothing capacitor of the full-wave rectifier, C. an inverter oscillator circuit incorporating two transistors having their bases connected by at least one primary winding of an output transformer, having their emitters respectively connected to individual windings of the output transformer whose other ends are connected to a first terminal of the emergency storage battery, and having their collectors connected directly together by a common collector line which is connected to a second terminal of the emergency storage battery, D. an ''''off'''' bias line connecting the junction of the smoothing capacitor and said first reverse current blocking diode through second reverse current blocking means to the bases of both transistors and thereby delivering reverse biasing potential to the emitter-base junctions of said traNsistors at all times when said single full-wave rectifier is activated by normal alternating current line power, and thereby maintaining the oscillator normally in a non-oscillating mode, E. an oscillator output transformer secondary winding incorporating a large plurality of turns having a first end connected in series with a first high-pass capacitor and having a second capacitor in parallel with said secondary winding and said first capacitor, F. an inductive impedance interposed between the junction of said capacitors and an output terminal tap connectable to a first terminal of the alternating current load, G. and a second terminal tap connected to the second end of said secondary winding, and connectable to a second terminal of the alternating current load, whereby interruption of alternating current line power normally delivered to the single full-wave rectifier interrupts the delivery of DC current therefrom to the storage battery and to the ''''off'''' bias line, removing the reverse bias from the base-emitter junctions of the transistors and thereby placing the oscillator in its oscillating mode.

Claim 6

An automatically activated emergency power supply system for load devices powered by high frequency alternating current comprising A. a single full-wave rectifier incorporating a smoothing capacitor across its positive and negative DC output terminals driven by normally available alternating current from a power line, B. a storage battery connected across the positive and negative output terminals of the single full-wave rectifier, with a first reverse current blocking diode being interposed between the positive terminal of the emergency storage battery and the smoothing capacitor of the full-wave rectifier, C. an inverter oscillator circuit incorporating two transistors having their bases connected by at least one primary winding of an output transformer, having their emitters respectively connected to individual windings of the output transformer whose other ends are connected to a first terminal of the emergency storage battery, and having their collectors connected directly together by a common collector line which is connected to a second terminal of the emergency storage battery, D. an ''''off'''' bias line connecting the junction of the smoothing capacitor and said first reverse current blocking diode through second reverse current blocking means to the bases of both transistors and thereby delivering reverse biasing potential to the emitter-base junctions of said traNsistors at all times when said single full-wave rectifier is activated by normal alternating current line power, and thereby maintaining the oscillator normally in a non-oscillating mode, E. an oscillator output transformer secondary winding incorporating a large plurality of turns having a first end connected in series with a first high-pass capacitor and having a second capacitor in parallel with said secondary winding and said first capacitor, F. an inductive impedance interposed between the junction of said capacitors and an output terminal tap connectable to a first terminal of the alternating current load, G. and a second terminal tap connected to the second end of said secondary winding, and connectable to a second terminal of the alternating current load, whereby interruption of alternating current line power normally delivered to the single full-wave rectifier interrupts the delivery of DC current therefrom to the storage battery and to the ''''off'''' bias line, removing the reverse bias from the base-emitter junctions of the transistors and thereby placing the oscillator in its oscillating mode.