I/O Device Control Unit With Solid-State Pick-And-Hold Relays for Electrical Power Control and Interconnection System for Activating the Relays in Sequence From a Service Processor
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2005-Feb-02
Each control unit has a pick-and-hold solid-state relay and related components that operate a conventional electromechanical power relay for connecting the control unit to an electrical power source. The control units have a common connection to a signal line P2 that is controlled by a service processor. A signal line P1 is connected from the service processor to the first control unit and from one control unit to the next. Each control unit has a second electromechanical relay, called POC (power on completion), that closes at the end of a power on operation and propagates signal P1 from one unit to the next. The coil of the power relay is in circuit with an active power supply of the control unit and with the solid-state pick relay.