Emergency lighting system
First Claim
1. An emergency lighting system for providing illumination from AC power in a normal mode and for providing illumination from a battery in an emergency mode, said system comprising:
- at least one gas discharge lamp;
a first DC/AC inverter connected to said lamp;
a DC power supply responsive to said AC power for generating DC power;
inverter control means responsive to an AC control signal and to a plurality of controls for controlling said first inverter to operate said one lamp from said DC power supply in said normal mode and from said battery in said emergency mode;
a light switch having an open position for manually turning off said one lamp in said normal mode said light switch being connected to said AC power to provide switched AC power; and
means responsive to said switched AC power for generating said AC control signal to turn off said first inverter when said light switch is in said open position.
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Accused Products
Abstract
This is an emergency lighting system which permits at least one gas discharge lamp to be operated from an AC power source when AC current is present and from a battery when AC signal is not present. The circuit also provides the capability for turning the lamp on under other selected emergency conditions such as in response to an intruder detection, or in response to detection of smoke, heat, water, or some other emergency. In order to converse battery power in the DC mode, controls are also provided for turning off the light or reducing its output level in response to such control inputs as an ambient light detector or manually operated dimmer control. The system also provides a number of other improved features which cause the system to operate more efficiently than prior systems for performing the same function, thus providing greater energy to the lamp with the same source energy input, and reducing the heat generated by the system. Features are also provided for protecting the battery and other components against damage.
120 Citations
44 Claims
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1. An emergency lighting system for providing illumination from AC power in a normal mode and for providing illumination from a battery in an emergency mode, said system comprising:
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at least one gas discharge lamp; a first DC/AC inverter connected to said lamp; a DC power supply responsive to said AC power for generating DC power; inverter control means responsive to an AC control signal and to a plurality of controls for controlling said first inverter to operate said one lamp from said DC power supply in said normal mode and from said battery in said emergency mode; a light switch having an open position for manually turning off said one lamp in said normal mode said light switch being connected to said AC power to provide switched AC power; and means responsive to said switched AC power for generating said AC control signal to turn off said first inverter when said light switch is in said open position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. In an electrical lighting circuit in which a gas discharge light is powered by a DC power source, said lighting circuit including a DC/AC inverter for converting DC power from said source into AC power, said DC/AC inverter generating AC power at a first frequency when powering said light and at a second frequency when said light is disconnected from said lighting circuit and means for applying said AC power to said light, a no-load protection circuit for preventing damage to said DC/AC inverter if said light is removed from lighting circuit, said no-load protection circuit comprising:
frequency-sensitive means connected in parallel with said light, said frequency-sensitive means having a sufficiently high first impedance at said first frequency so that little power is dissipated in said frequency-sensitive means and said frequency-sensitive means having a second impedance at said second frequency so that said frequency-sensitive means provides a load to said AC power at said second frequency. - View Dependent Claims (30)
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31. An electrical lighting circuit for powering a gas discharge light from a DC power source, said lighting circuit comprising:
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a DC/AC inverter for converting DC power from said source into AC power, said DC/AC inverter generating AC power at a first frequency when powering said light and at a second frequency when said light is disconnected from said lighting circuit; means for applying said AC power to said light; and frequency-sensitive means connected in parallel with said light, said frequency-sensitive means having a sufficiently high first impedance at said first frequency so that little power is dissipated in said frequency-sensitive means and said frequency-sensitive means having a second impedance at said second frequency so that said frequency-sensitive means provides a load to said AC power at said second frequency for preventing damage to said DC/AC inverter if said light is removed from lighting circuit. - View Dependent Claims (32, 33, 34)
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35. In an electrical lighting circuit in which a gas discharge light is powered by an AC power source operating at a first frequency by means of a ballast which generates electrical noise and by a DC power source in the absence of AC power, said lighting circuit including a DC/AC inverter for converting DC power from said DC power source into AC power at a second frequency which is substantially higher than said first frequency, said ballast and said DC/AC inverter being directly connected to said light, the improvement comprising:
frequency-sensitive means connected in series with said light and said DC/AC inverter, said frequency-sensitive means having a first impedance at said first frequency so that said frequency-sensitive means tends to block said noise and said first frequency signals and to prevent said noise and said first frequency signals from being applied to said DC/AC inverter and said frequency-sensitive means having a second impedance at said second frequency so that the loss caused by said frequency-sensitive means in series with said light is reduced at said second frequency. - View Dependent Claims (36)
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37. An electrical lighting circuit in which a gas discharge light is powered by an AC power source operating at a first frequency and by a DC power source int he absence of AC power, said lighting circuit comprising:
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a ballast connected in series with said AC power source and said light, said ballast generating electrical noise; a DC/AC inverter for converting DC power from said DC power source into AC power at a second frequency which is substantially higher than said first frequency, said DC/AC inverter being directly connected in parallel with said light; and frequency-sensitive means connected in series with said light and said DC/AC inverter, said frequency-sensitive means having a first impedance at said first frequency so that said frequency-sensitive means tends to block said noise and said first frequency signals and to prevent said noise and said first frequency signals from being applied to said DC/AC inverter and said frequency-sensitive means having a second impedance at said second frequency so that the loss caused by said frequency-sensitive means in series with said light is reduced at said second frequency. - View Dependent Claims (38, 39, 40, 41)
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42. An electrical lighting circuit in which a first gas discharge light is powered by an AC power source and a second gas discharge light is powered by a DC power source, said lighting circuit comprising:
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means connecting said first light to said AC power source to operate said first light from said AC source; switch means connected in series with said AC power source and said first light to turn said first light on and off; a DC/AC inverter for converting DC power from said DC power source into AC power, said DC/AC inverter comprising a free-running oscillator controlled by a feedback loop; means for connecting said DC/AC inverter to said second light to operate said second light from said DC/AC inverter; means connected in said feedback loop and responsive to the presence of AC power at said first light for controlling said oscillator to operate and generate AC power to operate said second light. - View Dependent Claims (43, 44)
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Specification