Coordinator for traffic signal controller
First Claim
1. A coordinator for a traffic signal controller including motor means and associated switching means for establishing the duty cycle of said controller, said controller being powered by AC mains connected to an electric power grid, said coordinator comprising detecting means and coordinating means responsive thereto for providing a synchronizing signal to said motor means and associated switching means during each duty cycle and in synchronization with the frequency of the alternating current provided to said controller by said AC mains, said detecting means comprising means for receiving AC signals from said mains and for receiving stray radiation having a frequency component of the frequency of said AC signal appearing on said power grid and for providing timing signals to said coordinating means, said coordinating means operating in response to said timing signals for producing said synchronizing signals based on said timing signals.
1 Assignment
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Accused Products
Abstract
A coordinator for a traffic signal controller having a motor and associated switching system for establishing the duty and width cycle of the controller. The controller being connected, via electrical circuitry, to an AC power grid. The coordinator is a self-contained unit arranged for connection to the controller to effect coordination thereof by producing timing signals in response to receipt of either AC signals from the electrical circuitry or stray AC radiation from adjacent sections of the power grid. The coordinator also includes an independent oscillator for producing independent timing signals. Thus, the coordinator can maintain coordination of the controller under normal operating conditions or under the abnormal operating conditions of a local power failure or a general power failure.
10 Citations
22 Claims
- 1. A coordinator for a traffic signal controller including motor means and associated switching means for establishing the duty cycle of said controller, said controller being powered by AC mains connected to an electric power grid, said coordinator comprising detecting means and coordinating means responsive thereto for providing a synchronizing signal to said motor means and associated switching means during each duty cycle and in synchronization with the frequency of the alternating current provided to said controller by said AC mains, said detecting means comprising means for receiving AC signals from said mains and for receiving stray radiation having a frequency component of the frequency of said AC signal appearing on said power grid and for providing timing signals to said coordinating means, said coordinating means operating in response to said timing signals for producing said synchronizing signals based on said timing signals.
Specification