EET-215 Lecture Notes - Lecture 1: Humber College, 5,6,7,8, Octal
Document Summary
Converting from relay logic to ladder logic. There are five number systems that are used with programmable. A multi-turn coil, wound on an iron core, to form an electromagnet. When the coil is energised, by passing current through it, the core becomes temporarily magnetised. The magnetised core attracts the iron armature. The armature is pivoted which causes it to operate one or more sets of contacts. When the coil is de-energised the armature and contacts are released. Type control: programmable controllers offer several advantages over a conventional relay type of control, relays have to be hardwired to perform a specific function, when the system requirements change, the relay wiring has to be changed or modified. In extreme cases, such as in the auto industry, complete control panels had to be replaced since it was not economically feasible to rewire the old panels with each model changeover. Contact are in the open position (6-8 and 1-3 in figure)
