Patent ID: 7795756
Filing Date: 2010-09-14
Classification: H02J

Abstract:
1. An circuit for switching between a utility power source and an emergency power source for a traffic light controller during failure and restoration of the permanent power source, comprising: a traffic light controller, a control panel, said control panel further comprising traffic light controller contacts, utility power contacts, emergency power contacts, and a power relay coil, said traffic light controller contacts being connected to said utility power contacts during normal operation and said traffic light controller contacts being connected to said emergency power contacts upon the energizing of said power relay coil during emergency operation, a switching relay, said switching relay further comprising a switching relay coil and switching relay contacts, said switching relay contacts being responsive to the energizing of said switching relay coil, said switching relay coil being de-energized during normal operation and said switching relay contacts being open during normal operation, said switching relay coil becoming energized during emergency operation and said switching relay contacts being closed during emergency operation, an emergency power connector, said emergency power connector being attachable to an emergency power source, a generator service switch, said generator switch connecting said emergency power connector to said switching relay and said power relay coil, said generator switch being open during normal operation, whereby when said generator service switch is open, said switching relay coil and said power relay coil are open and utility power is sent to said traffic light controller, and when said generator service switch is closed, said switching relay coil and said power relay coil are open and power from said emergency power connector is sent to said traffic light controller.