Electronic time switches
First Claim
1. An electronic switch for controlling a street lighting system having at least one street light, comprising:
- at least one switching device,a reference frequency source,a microprocessor, anda means for applying to the microprocessor inputs representative of at least the current time and date and the latitude at which the switch is to be used,the microprocessor being responsive to the reference frequency source and the current time and date inputs to implement a real time clock and calendar, and being arranged to calculate from the date provided by said real time clock and calendar and from the latitude input the respective times of at least one of sunrise and sunset at said location on each of a plurality of days, and to operate the switching device to turn on and off at least one street light of the street lighting system at respective switching times dependent upon the calculating times,wherein the means for applying is arranged to apply to the microprocessor a further input representative of an equivalent time offset, and the microprocessor is arranged to calculate said respective times in dependence on the equivalent time offset as well as said latitude and the time and date.
1 Assignment
0 Petitions
Accused Products
Abstract
An electronic switch comprising at least one switching device 70,72, a reference frequency source 58, a microprocessor 50 and means for applying to the microprocessor inputs representative of at least the current time and date and the latitude at which the time switch is to be used 31-36, the microprocessor being 50 responsive to the reference frequency source 58 and the current time and date inputs to implement a real time clock and calendar 62, and being arranged to calculate from the date provided by said real time clock and calendar and from the latitude input the respective times of at least one of sunrise and sunset at said location on each of a plurality of days, and to operate the switching device 70,72 at respective switching times dependent upon the calculated times.
42 Citations
15 Claims
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1. An electronic switch for controlling a street lighting system having at least one street light, comprising:
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at least one switching device, a reference frequency source, a microprocessor, and a means for applying to the microprocessor inputs representative of at least the current time and date and the latitude at which the switch is to be used, the microprocessor being responsive to the reference frequency source and the current time and date inputs to implement a real time clock and calendar, and being arranged to calculate from the date provided by said real time clock and calendar and from the latitude input the respective times of at least one of sunrise and sunset at said location on each of a plurality of days, and to operate the switching device to turn on and off at least one street light of the street lighting system at respective switching times dependent upon the calculating times, wherein the means for applying is arranged to apply to the microprocessor a further input representative of an equivalent time offset, and the microprocessor is arranged to calculate said respective times in dependence on the equivalent time offset as well as said latitude and the time and date. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An apparatus comprising:
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electronic switching device for controlling a street lighting system having at least one street light, a reference frequency source, means for providing inputs representative of at least the current time and date and the latitude at which the switch is to be used, and an equivalent time offset, a microprocessor being responsive to the reference frequency source and the current time and date inputs to implement a real time clock and calendar, and being arranged to calculate from the date provided by said real time clock and calendar and from the latitude input the respective times of at least one of sunrise and sunset at said location on each of a plurality of days, and to operate the electronic switching device to turn on and off the at least one street light of the street lighting system at respective switching times dependent upon the calculated times and equivalent time offset. - View Dependent Claims (8, 9, 10, 11, 12)
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13. An apparatus comprising:
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electronic switch comprising two switching devices connected to control a street lighting system having at least one street light, a reference frequency source, means for providing inputs representative of at least the current time and date and the latitude at which the time switch is to be used, a microprocessor being responsive to the reference frequency source and the current time and date inputs to implement a real time clock and calendar, arranged to calculate from the date provided by said real time clock and calendar and from the latitude input the respective times of at least one of sunrise and sunset at said location on each of a plurality of days, and to operate the electronic switching device at respective switching times dependent upon the calculated times, and arranged to independently operate the two switching devices to turn on and off the at least one street light of the street lighting system in dependence upon said calculated times in accordance with a first and second daily switching program respectively, the microprocessor being arranged to alternate the application of said switching programs between the switching devices so as to tend to maintain their respective cumulative on periods substantially equal, and arranged to switch the switching device on at a switching time dependent upon or equal to the calculated time of one of sunset or sunrise and to switch the switching device off at a switching time dependent upon or equal to the calculated time of the other of sunrise or sunset. - View Dependent Claims (14)
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15. An electronic switch for controlling a street lighting system having at least one street light comprising:
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at least one switching device, a reference frequency source, a microprocessor, and a means for applying to the microprocessor inputs representative of at least the current time and date and the latitude at which the switch is to be used, the microprocessor being responsive to the reference frequency source and the current time and date inputs to implement a real time clock and calendar, and being arranged to calculate from the date provided by said real time clock and calendar and from the latitude input the respective times of at least one of sunrise and sunset at said location on each of a plurality of days, and to operate the switching device to turn on and off at least one of the street lighting system at respective switching times dependent upon the calculating times, wherein the microprocessor is arranged to switch the switching device on at a switching time dependent upon or equal to the calculated time of one of sunrise or sunset and to switch the switching device off at a switching time dependent upon or equal to the calculated time of the other of sunrise or sunset.
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Specification