power supply - снабжение энергией;
alternating current transformers - трансформаторы переменного тока;
cold we'ather operation of the machine - работа машины в условиях холодной погоды;
transmission line performance - работа линий передач
36. /40 мин./ Внимательно читая текст, выпишите новые слоям » словарики. Затем найдите в техническом словаре подходящее п® смыслу значение каждого слова. При третьем чтении постарайтесь найти отняты на следующие вопросы. /Т.к. предлагаемый ниже текст является первым, который знакомит вас с основами автоматизации на английском языке, то хотелось бы, чтобы трудности, связанные с чтением этого материала, не ослабили ваше желание получать информаций) по специальности и на английском языке./
1. What kind of devices are inductance transducers? 2. What paragraph deals with a transduction coil? 3. What does this paragraph say about the coil? 4. What advantages do inductance transducers show?
Automation Means of Control & Inspection.
Inductance Transducers
Inductance transducers are devices fti which the electric output results from the variation of the self-induction of a single coil.
. Some designs contain two coils collected as two arms of an inductive bridge. In such transducers tfie transduction coil has a stationary core but changes its inductance.with the distance between itself & a moving ferromagnetic object. Thus, their input is the displacement of the armature that causes a change in the reluctance path / air gap / while ae excitation is applied to the coil system, & hence a change in the induced current.
A schematic of a typical inductance transducer /differential transformer/ is given in Fig. 2. A rod 5 causes a sensing shaft 4 to move, which in turn displaces an armature 2 placed between cores. Primary windings Z1 & Z2 use ac excitation & are put in series so
that when the armature is centered, i.e. air gaps are equal, magnetic {luxes in cores 1 & 3 are in equilibrium, secondaries Z3 & Z4 are identical but connected to oppose each other, so that when the armature is centered the; output is zero. When the armature is moved to the center, while ac excitation is applied to the coil system, the.reluctance path changes upsetting the magnetic flux equilibrium in the cores 1 & 3, varying the induced voltage in the secondaries. The output current Will thus be the quantity derived from the difference between the enduced emf’s. Such devices are often referred to as variable air gap inductance transducers. Inductance transducers show many advantages which can be summarized as follows:
