Abstract: An electrical circuit comprising a power supply, a load, a first pair of parallel positive cables between the power supply and the load, a first pair of parallel negative cables between the load and the power supply, and incendive arc prevention means, in which the incendive arc prevention means comprises monitoring means adapted to monitor the first pair of positive cables and the first pair of negative cables, and to detect if the current and/or voltage in one of the first pair of positive cables deviates from the other, and if the current and/or voltage in one of the first pair of negative cables deviates from the other, and in which the incendive arc prevention means comprises a control means adapted to fully or partially isolate the power supply from the first pair of positive cables and the first pair of negative cables if the monitoring means detects that the current and/or voltage of one of the first pair of positive cables has deviated from the other, or if the current and/or voltage of one of the fi

Abstract: An electrical circuit comprising a power supply, a load, a pair of parallel positive cables between the power supply and the load, a pair of parallel negative cables between the load and the power supply, and incendive arc prevention means, comprising: monitoring means adapted to detect if the current and/or voltage in one of the pair of cables deviates from the other, and a control means adapted to fully or partially isolate the power supply from the pair of cables if the monitoring means detects that their current and/or voltage has deviated from the other, characterised in which: the electrical circuit comprises a common positive section between the power supply and the pair of positive cables, and a common negative section between the pair of negative cables and the power supply, in which a first modulation means is adapted to generate a modulated communications signal.

Abstract: Data signal isolation apparatus comprising a first media converter adapted to convert outgoing electrical data signals into outgoing optical data signals, an optical data signal transmission means adapted to transmit said outgoing optical data signals, a second media converter adapted to convert said outgoing optical data signals back into outgoing electrical data signals, and an intrinsically safe power supply, in which the optical data signal transmission means comprises an electrical isolation gap, and in which the second media converter is powered by the intrinsically safe power supply.