4 Home tasks
4.1 To study theoretical material using the literature [2.1…2.5] and methodical instructions to this work
peculiarities of structure and functional building of rectifying devices;
Picture 3.6 – Scheme of rectification with П-type CLC filter (k = 5)
peculiaries and limitations, put on schemotechnical realization of separate functional nodes of rectifying devices;
processes of functioning in the bridge scheme of rectification, time diagrams of voltages and currents of its elements;
peculiarities of laboratory stand;
finding the main calculation correlations in different modes of rectifier’s.
4.2 To study the methodical instructions to this laboratory work.
4.3 To prepare the protocols, where the information for processing of this lab Work is represented.
4.4 To study the function of each element of the rectifying, purpose of each experiment, expected results of the research.
4.5 Answer the control questions.
4.6 To study the peculiarities of electrical processes, happening in different parts of the rectifier’s ,explaining the external characteristics of the rectifier Uн = f (Iн) on active, inductive and capacitive character of the load.
4.7 To draw the schemes of single-phase bridge rectifier with capacitive and inductive, the diagrams of voltages uн(t) and currents iн(t) in the load circuit, iVD1(t)…iVD4(t), diodes of the block of rectification, iс(t) of the source G1 for active , inductive and capacitive characters of the load of perfect rectifier.
5 Control questions
5.1 Under what limitations derive calculated formulas, characterizing the process of rectification in the investigated scheme with a load of capacitance, the inductive nature?
5.2 What is the angle of the current cutoff of the valve, does it depend on the magnitude current of the load?
5.3 How to explain non-linearity of the external characteristic of rectifying scheme under the load of capacitive character?
5.4 Are there any advantages of the scheme on the capacitive load, if so, what are they?
5.5 Why is the graph of the external characteristics under the capacitive load situated of the graph of external characteristics of the inductive load?
5.6 What are the advantages and disadvantages of a bridge circuit of rectification? Give it a comparative evaluation with other schemes of rectification.
5.7 What is “the ratio of the transformer’s usage?
5.8 What will be the form of current in the primary winding of the transformer in the bridge circuit? How is this form connected with the form of current in the secondary winding?
5.9 What determines the value of a variable component in the rectified voltage under the capacitive, inductive load?
5.10 How to determine the efficiency of the rectifier theoretically and by the data obtained experimentally?
5.11 Explain the work of the rectifier scheme with an active, inductive and capacitive loads.
5.12 Explain the diagrams of the rectified voltage uв(t), current iв(t) in the circuit of the load, current through the diode iд(t), current i2(t) of the secondary winding of the transformer with an active, inductive and capacitive loads..
5.13 Compare the schemes for different character of the load, using the basic relations of the currents, voltages and capacities.
5.14 Explain the external characteristics of the rectifier at work on an active, inductive and capacitive loads.
5.15 What is the difference between the oscillograms obtained in the performance of the laboratory work, and the oscillograms given in the homework for inductive and capacitive loads?
5.16 Indicate the advantages and disadvantages of a bridge circuit of rectification comparatively with other single-phase rectification circuits.
5.17 List all types of rectifying filters. Explain the features of their functioning.
5.18 Give definitions of the basic parameters of rectifying filters. The main indicators of quality and requirements for the rectifying filter.
5.19 Give a comparative evaluation of rectifying filters investigated in this laboratory work.
5.20 When is it advisable to use filters, consisting only capacitor, or only one inductor?