摘要 |
An electrical supply system has two power generators 10 and 20, several items of electrical equipment 101 to 106 and 201 to 206, and a processor 3 that controls disconnection of the equipment if demand should exceed supply. The processor 3 has a hardware switch 35 controlled by outputs from the generators 10 and 20. The processor runs two different programs A and B at the same time but the switch 35 supplies only one of these to the output 34. When equipment needs to be disconnected, for example when one of the generators 10, 20 fails, the switch changes to supply the results of the other program to the output and this effects the disconnection. When sufficient supply is restored, the switch changes back to its original state to supply the results of the first program to the output of the processor. <IMAGE> |