by Colin McIntosh, The Cambridge English Dictionary is constantly being updated and expanded to reflect the interests of our users. One area of particular interest to our users is that of English Language Teaching (ELT), and a number of ELT terms have recently been added to the dictionary.y Colin McIntosh, The Cambridge English Dictionary is constantly being updated and expanded to reflect the interests of our users. One area of particular interest to our users is that of English Language Teaching (ELT), and a number of ELT terms have recently been added to the dictionary.
A diode is a one-way âvalveâ for electric current, analogous to a check valve for those familiar with plumbing and hydraulic systems. Ideally, a diode provides unimpeded flow for current in one direction (little or no resistance), but prevents flow in the other direction (infinite resistance).
Three way valve. Four way valve. Four way 5 ported valve. Arrows are used to indicate the flow directionA âteeâ indicates that a port or âwayâ is blocked(closed or non passing).Lines or connections are only drawn to one valve position and are drawn to the normal unactuated valve position.