Safe DC outlet and arc suppressor
This paper introduces a new solid-state circuit for DC power outlet with arc suppression capability. The principle of operation is to detect the load connection instant (or disconnection) to immediately energize (or de-energize) the outlet. The two poles mechanical assembly is formed by a permanent magnet in the two poles receptacle, a Hall Effect sensor in the jack and a solid estate device to perform the electric connection o dis connection of the electric load.
Power contact arc suppression An investigation into the relative effectiveness of snubbers vs. an engineered electronic power contact arc suppressor
Power contact arc suppression is specific to arcing in contacts that switch currents in excess of one ampere. To facilitate this discussion, a contact arc suppression figure-of-merit is introduced enabling a comparison of arc suppression effectiveness between electronic components and engineered solutions. This “Contact Arc Suppression Factor” (CASF), is the ratio of the arc energy without suppression over the residual arc energy with suppression. A CASF of 1 indicates no effect whereas a CASF of 1000 indicates a 99.9 percent reduction in arc energy. This paper concludes by summarizing the relevant key elements from this investigation that enabled the construction of power contact arc suppressors capable of suppressing arc currents well in the kilo ampere range irrespective of the type of load driven by operating voltages in the kilo volt range.
Flow in a branching open channel: a review
Branching channel flow refers to any side water withdrawals from rivers or main channels. Branching channels have wide application in many practical projects, such as irrigation and drainage network systems, water and waste water treatment plants, and many water resources projects. In the last decades, extensive theoretical and experimental investigations of the branching open channels have been carried out to understand the characteristics of this branching flow, varying from case studies to theoretical and experimental investigations. The objectives of this paper are to review and summarise the relevant literatures regarding branching channel flow. These literatures were reviewed based on flow characteristics, physical characteristics, and modeling of the branching flow. Investigations of the flow into branching channel show that the branching discharge depends on many interlinked parameters. It increases with the decreasing of the main channel flow velocity and Froude number at the upstream of the branch channel junction. Also it increases with the increasing of the branch channel bed slope. In subcritical flow, water depth in the branch channel is always lower than the main channel water depth. The flow diversion to the branch channel leads to an increase of water depth at the downstream of the main channel. From the review, it is important to highlight that most of the study concentrated on flow characteristics in a right angle branch channel with a rigid boundary. Investigations on different branching angles with movable bed have still to be explored.