CIRCUITS FOR PHOTOVOLTAIC APPLICATIONS

An electrical transmission safety system for connection of direct current (DC) power from a DC power source to a load comprises: a connection from the power source to the load, the connection comprising a positive terminal and a negative terminal; a first solid state switch electrically connected between the power source and one of the positive terminal and negative terminal; and a switch-control isolation block comprising a first optocoupler, the first optocoupler providing electrical isolation from the power source for generating a first isolated switch-control signal in response to a switch-control input signal, the switch-control isolation block connected to provide the first isolated switch-control signal to the first solid state switch to thereby control an ON or OFF conduction state of the first solid state switch and corresponding current flow between the power source and the load through the one of the positive terminal and negative terminal.