Patent ID: 6853152

Claim:
A safety interlock system for an electrical device that includes a power supply and an electrical load, comprising: a DC power supply and a ballast power supply, the ballast power supply including a ballast control circuit and a ballast power circuit, and the ballast control circuit producing control signals for delivery to the ballast power circuit to control its operation; a relatively low voltage electrical connection between the DC power supply and the ballast power supply, the relatively low voltage electrical connection supplying a relatively low voltage for control of the operation of the ballast power supply; and a switch positioned in operative association with the ballast power supply to provide an interruptible low voltage electrical connection that controls production of the control signals or their delivery to the ballast power circuit, the switch having a first state in which the relatively low voltage electrical connection enables production and delivery of the control signals to and thereby enables power output from the ballast power supply to operate the electrical device, and the switch having a second state in which the relatively low voltage electrical connection does not enable production and delivery of the control signals to the ballast power circuit to interrupt power from the ballast power supply and thereby enable safe servicing of the electrical device.