Apparatus for controlling traffic lights
First Claim
1. A device for providing an orderly shutdown of a system of interconnected traffic lights upon loss of its primary electrical power, the system including a reserve source of electrical power and a traffic controller, the traffic controller for providing traffic control signals to selectively illuminate the traffic lights in either of a normal operating mode or a flashing mode, the device comprising:
- means for detecting loss of the primary electrical power;
means responsive to said primary power loss detecting means for switching said device from said primary source of electrical power to said reserve source of electrical power;
means for determining when said traffic controller has placed said traffic lights in a safe condition; and
means responsive to said primary power loss detecting means and said safe condition determining means for commanding said traffic controller to transfer said traffic lights from the safe condition of said normal operating mode to said flashing mode.
1 Assignment
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Accused Products
Abstract
A device for providing an orderly shut-down of a system of interconnected traffic lights upon loss of its primary electrical power is disclosed. A device for permitting consistent reapplication of power to a line conditioner having a ferroresonant transformer is also disclosed. Further, a battery charger for charging a battery system including a plurality of battery cells coupled in series is disclosed. Additionally, a device for determining proper operation of a power transistor by monitoring its saturation voltage and emitter current is also disclosed. Finally, a device for generating a first alternating signal in-phase with a separately generated second alternating signal is disclosed.
24 Citations
11 Claims
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1. A device for providing an orderly shutdown of a system of interconnected traffic lights upon loss of its primary electrical power, the system including a reserve source of electrical power and a traffic controller, the traffic controller for providing traffic control signals to selectively illuminate the traffic lights in either of a normal operating mode or a flashing mode, the device comprising:
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means for detecting loss of the primary electrical power; means responsive to said primary power loss detecting means for switching said device from said primary source of electrical power to said reserve source of electrical power; means for determining when said traffic controller has placed said traffic lights in a safe condition; and means responsive to said primary power loss detecting means and said safe condition determining means for commanding said traffic controller to transfer said traffic lights from the safe condition of said normal operating mode to said flashing mode. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A traffic control system for providing an orderly shut-down of a system of interconnected traffic lights upon loss of its primary electrical power, the system comprising:
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a traffic controller for providing traffic control signals to selectively illuminate said traffic lights in either of a normal operating mode or a flashing mode; a switch; a reserve source of electrical power; means for detecting the status of said primary source of power; means responsive to said detecting means for alternately switching said device from said primary source of electrical power to said reserve source of electrical power; means for determining when said traffic controller has placed said traffic lights in a safe condition; and means responsive to said safe condition determining means and loss of said primary electrical power for commanding said traffic controller to transfer said traffic lights from the safe condition of said normal operating mode to said flashing mode. - View Dependent Claims (9, 10, 11)
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Specification