Functional diagrams showing the processes that occur within an article and within individual components are used in studying the functional capabilities of the article, as well as in installation, adjustment, control, and repair work.
In basic diagrams, the standard symbols for the circuit components are arranged in correspondence with the operational principle of the device, as well as to facilitate the reading of the diagram. In design diagrams, all or some of the components are represented as equivalent circuits;
Devices with an individual physical identity, such as amplifiers, transistors, loudspeakers, and generators, are often represented by equivalent circuits for purposes of analysis. These equivalent circuits are made up of the basic passive and active elements listed above.
The devices in an electronic circuit are classified as being either passive or active. The passive devices change signal energy, as is done dynamically by capacitors and statically by transformers, or absorb signal energy, as occurs in resistors, which also act to convert voltages to
The MOSFET is a versatile device, acting as a voltage-controlled current source in the saturation region and approximately as a voltage-controlled resistor in the resistive region. It can also be electronically controlled between cutoff and the resistive region to make it act as a switch,
In modeling a system, some parameters are first defined and equations governing system behavior are obtained. A block diagram is constructed, and the transfer function for the whole system is determined.
The dimensions of printed circuit boards, the position of the hole centers, and the hole diameters are standardized. The boards are 10–360 mm long, 10–240 mm wide, and 0.05–3.0 mm thick (depending on the rigidity required). The spacing of the coordinate grid for marking the
Fortunately, most of these transistors occur in pairs, such as the npn and the pnp bipolar junction transistors, or the n-channel and the p-channel MOSFETs, allowing designers to work symmetrically with positive and negative signals and sources. This statement may be clarified by noting that
Circuit diagrams show connectors between components and the locations of connectors and lead-ins; such diagrams also illustrate methods of laying out, mounting, and fastening conductors, cables, and piping. Others show external connections to other articles; such diagrams are used for the installation and operation of
Electric circuits are used to transmit power as in high-voltage power lines and transformers or in low-voltage distribution circuits in factories and homes; to convert energy from or to its electrical form as in motors, generators, microphones, loudspeakers, and lamps; to communicate information as in