Emergency lighting system
First Claim
1. In combination with a lighting system comprising an alternating current utility power source, an "on-off" switch and a plurality of fluorescent lights coupled to said utility power source through said "on-off" switch, each one of said plurality of fluorescent lights being provided with a ballast, an emergency system comprising:
- an emergency power supply having a frequency higher than the frequency of said utility power source;
a transfer switch having a first contact directly connected to said utility power source, a second contact connected to said emergency power supply and a switch arm connected to said "on-off" switch, said transfer switch being so arranged that said switch arm is closed on said first contact when power is available from said utility power source and is automatically transferred from said first contact to said second contact when power is not available from said utility power source whereby power for illuminating said plurality of fluorescent lights is provided by said emergency power supply through said "on-off" switch when power is not available from said utility power source; and
means for illuminating one or more but not all of said plurality of fluorescent lights when power for illuminating said plurality of fluorescent lights is provided by said emergency power supply, said ballast provided with each one of said plurality of fluorescent lights presenting such a high impedance to said higher frequency power from said emergency power supply that each one of said plurality of fluorescent lights cannot be effectively illuminated from said higher frequency emergency power supply through its respective said ballast.
0 Assignments
0 Petitions
Accused Products
Abstract
A system which will provide emergency lighting as desired when the normal power supply such as the utility power is interrupted or otherwise not available. The system provides the emergency power by means of the same wiring that is used to provide the utility power to the lights. In addition, the "on-off" switch or switches used to control the turning on and off of the lights when the utility power is available also provides control of the lights when the emergency supply is being utilized.
-
Citations
10 Claims
-
1. In combination with a lighting system comprising an alternating current utility power source, an "on-off" switch and a plurality of fluorescent lights coupled to said utility power source through said "on-off" switch, each one of said plurality of fluorescent lights being provided with a ballast, an emergency system comprising:
-
an emergency power supply having a frequency higher than the frequency of said utility power source; a transfer switch having a first contact directly connected to said utility power source, a second contact connected to said emergency power supply and a switch arm connected to said "on-off" switch, said transfer switch being so arranged that said switch arm is closed on said first contact when power is available from said utility power source and is automatically transferred from said first contact to said second contact when power is not available from said utility power source whereby power for illuminating said plurality of fluorescent lights is provided by said emergency power supply through said "on-off" switch when power is not available from said utility power source; and means for illuminating one or more but not all of said plurality of fluorescent lights when power for illuminating said plurality of fluorescent lights is provided by said emergency power supply, said ballast provided with each one of said plurality of fluorescent lights presenting such a high impedance to said higher frequency power from said emergency power supply that each one of said plurality of fluorescent lights cannot be effectively illuminated from said higher frequency emergency power supply through its respective said ballast. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. In combination with a lighting system comprising an alternating current utility power source, an "on-off" switch and a plurality of incandescent lights coupled to a utility power source through said "on-off" switch, an emergency system comprising:
-
an emergency power supply having a frequency higher than the frequency of said utility power source; a transfer switch having a first contact directly coupled to said utility power source, a second contact connected to said emergency power supply and a switch arm connected to said "on-off" switch, said transfer switch being so arranged that said switch arm is closed on said first contact when power is available from said utility power source and is automatically transferred from said contact to said second contact when power is not available from said utility power source whereby power for illuminating said plurality incandescent lights is provided by said emergency power supply through said "on-off" switch when power is not available from said utility power source; and means for holding off a selected number of said plurality of incandescent lights when said switch arm is closed on said second contact of said transfer switch whereby one or more but not all of said plurality of incandescent lights are illuminated when power is not available from said utility power source. - View Dependent Claims (9, 10)
-
Specification