الرسم التخطيطي للمراحل - الرسوم التخطيطية للدارات الالكترونية .. الإلكترونيات

Phase Diagram - Circuit Diagrams .. Electronics

Phase Diagram

It is possible to explain the main important parts of the circuit without going into its various details. Phase diagrams serve this purpose. Figure (51) is nothing but a schematic drawing of a large amplifier circuit, each square or "box" in which symbolizes one of its complete stages.

Stage 1 is the audio frequency amplifier circuit similar to the circuit in Figure (49), and so is stage 2. As for stage 3, it is the output stage, i.e. the stage that takes the signal from the second stage and gives it sufficient power before giving it to the loudspeaker.

Figure (52A) represents a schematic drawing of a stereo CD listening device. In it, the stereo receiver generates two channels of signals, one on the right track and the other on the left track. Then the two signals resulting from the stereo receiver are combined inside a section whose task is to balance the two signals and adjust the volume of the two channels. The amplifiers feed both the right and left speakers with the signals resulting from the outputs of the two channels after balancing and amplifying them.

Figure (52b) represents a schematic drawing of the stages of the photoelectric goods counter that operates when the goods interrupt the light falling on the cell, generating an electrical output signal that operates the counter.

51 - A step-by-step drawing of an audio amplifier
52 - Step-by-step drawings of an amplifier. A solid-state model and a photoelectric meter.
53 - Representation of a transistor and a thermionic triode.

Some other symbols used in the circuit

Figure (53a) shows an MSM transistor and its symbol. Figure (53b) shows an SMMS transistor and its symbol. While Figure (3.5c) shows a triode and the symbol that represents it as well. It must be noted that the symbols are only simplified representations of all the components of the circuit or its functions. An example of this is the relay (54) which consists of the connection ends S S through which the current passes to the coils of an electromagnet via a spring contact S that is in a state of rest raised upwards and connected to the fixed contact. When the current passes through the coils of the electromagnet, the plate S moves and attracts the contact towards it, thus transferring the circuit to position 02.

Some details can sometimes be omitted when representing electronic circuits in order to simplify them and facilitate their study. In Figure (55), for example, we find that the task of the switch is to select one of the inductors L1, L2, L3, L4, and these

55 - Some lines were deleted in order to clarify the drawing.

The circuit appears in full in Figure (55a), while Figure (55b) represents the actual state of the circuit after Selecting the inductance is not at the time when the remaining inductances L2, L3, L4 are cancelled.

It must be noted that this simplification is very important, especially if the circuit contains many switches in different positions or if it contains a large number of inductors, capacitors or other known circuit parts.

The theoretical circuit diagrams do not take into account the way in which the circuit is assembled. For example, an amplifier circuit can be assembled on a large board that occupies a large space, and it can be assembled on a small board that occupies a very limited space, either by placing the components close together, or by using very small components. Figure 52 shows some other different symbols.

56 - Other different symbols.