Computer and Networks Area

"Fault-tolerant computer systems are systems designed around the concepts of fault tolerance. In essence, they have to be able to keep working to a level of satisfaction in the presence of faults. ...
Most fault-tolerant computer systems are designed to be able to handle several possible failures, including hardware-related faults such as hard disk failures, input or output device failures, or other temporary or permanent failures; software bugs and errors; interface errors between the hardware and software, including driver failures; operator errors, such as erroneous keystrokes, bad command sequences, or installing unexpected software; and physical damage or other flaws introduced to the system from an outside source." [Fault-tolerant computer system. Wikipedia]
The computer network diagram example "Cisco LAN fault-tolerance system" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Cisco Network Diagrams solution from the Computer and Networks area of ConceptDraw Solution Park.

The vector stencils library "Cisco switches and hubs" contains 26 symbols of Cisco switches and hubs for drawing computer network diagrams.
"A switch is a device used on a computer network to physically connect devices together. Multiple cables can be connected to a switch to enable networked devices to communicate with each other. Switches manage the flow of data across a network by only transmitting a received message to the device for which the message was intended. Each networked device connected to a switch can be identified using a MAC address, allowing the switch to regulate the flow of traffic. This maximises security and efficiency of the network. Because of these features, a switch is often considered more "intelligent" than a network hub. Hubs neither provide security, or identification of connected devices. This means that messages have to be transmitted out of every port of the hub, greatly degrading the efficiency of the network." [Network switch. Wikipedia]
"An Ethernet hub, active hub, network hub, repeater hub, multiport repeater or hub is a device for connecting multiple Ethernet devices together and making them act as a single network segment. It has multiple input/ output (I/ O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming. A hub works at the physical layer (layer 1) of the OSI model. The device is a form of multiport repeater. Repeater hubs also participate in collision detection, forwarding a jam signal to all ports if it detects a collision." [Ethernet hub. Wikipedia]
The symbols example "Cisco switches and hubs - Vector stencils library" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Cisco Network Diagrams solution from the Computer and Networks area of ConceptDraw Solution Park.
www.conceptdraw.com/ solution-park/ computer-networks-cisco

The vector stencils library "Transformers and windings" contains 29 element symbols of transformers, windings, couplers, metering devices, transductors, magnetic cores, chokes, and a variometer.
Use it to design the electromechanical device schematics and electronic circuit diagrams.
"A transformer is an electrical device that transfers energy between two circuits through electromagnetic induction. Transformers may be used in step-up or step-down voltage conversion, which 'transforms' an AC voltage from one voltage level on the input of the device to another level at the output terminals. This special function of transformers can provide control of specified requirements of current level as an alternating current source, or it may be used for impedance matching between mismatched electrical circuits to effect maximum power transfer between the circuits.
A transformer most commonly consists of two windings of wire that are wound around a common core to induce tight electromagnetic coupling between the windings. The core material is often a laminated iron core. The coil that receives the electrical input energy is referred to as the primary winding, while the output coil is called the secondary winding.
An alternating electric current flowing through the primary winding (coil) of a transformer generates an electromagnetic field in its surroundings and a varying magnetic flux in the core of the transformer. By electromagnetic induction this magnetic flux generates a varying electromotive force in the secondary winding, resulting in a voltage across the output terminals. If a load impedance is connected across the secondary winding, a current flows through the secondary winding drawing power from the primary winding and its power source." [Transformer. Wikipedia]
"An electromagnetic coil (or simply a "coil") is formed when a conductor is wound around a core or form to create an inductor or electromagnet. When electricity is passed through a coil, it generates a magnetic field. One loop of wire is usually referred to as a turn or a winding, and a coil consists of one or more turns. For use in an electronic circuit, electrical connection terminals called taps are often connected to a coil. Coils are often coated with varnish or wrapped with insulating tape to provide additional insulation and secure them in place. A completed coil assembly with one or more set of coils and taps is often called the windings.
Windings are used in transformers, electric motors, inductors, solenoids, loudspeakers, and many other applications." [Electromagnetic coil. Wikipedia]
The shapes example "Design elements - Transformers and windings" was drawn using the ConceptDraw PRO diagramming and vector drawing software extended with the Electrical Engineering solution from the Engineering area of ConceptDraw Solution Park.

The vector stencils library "HVAC controls" contains 23 symbols of HVAC controls (sensors, actuators, timers, controllers, I/ O points).
"HVAC (... Heating, Ventilation and Air Conditioning) is a control system that applies regulation to a heating and/ or air conditioning system. ...
Central controllers and most terminal unit controllers are programmable, meaning the direct digital control program code may be customized for the intended use. The program features include time schedules, setpoints, controllers, logic, timers, trend logs, and alarms. The unit controllers typically have analog and digital inputs that allow measurement of the variable (temperature, humidity, or pressure) and analog and digital outputs for control of the transport medium (hot/ cold water and/ or steam). Digital inputs are typically (dry) contacts from a control device, and analog inputs are typically a voltage or current measurement from a variable (temperature, humidity, velocity, or pressure) sensing device. Digital outputs are typically relay contacts used to start and stop equipment, and analog outputs are typically voltage or current signals to control the movement of the medium (air/ water/ steam) control devices such as valves, dampers, and motors." [HVAC control system. Wikipedia]
Use the design elements library "HVAC controls" for drawing the HVAC system diagrams, controls drawings, and automated building control and environmental control system layuout floor plans using the ConceptDraw PRO diagramming and vector drawing software.
The shapes library "HVAC controls" is included in the HVAC Plans solution from the Building Plans area of ConceptDraw Solution Park.

The vector stencils library "Computer peripheral devices" contains 18 clipart images of computer peripheral devices and equipment for drawing network diagrams.
"A peripheral is a device that is connected to a host computer, but not an integral part of it. It expands the host's capabilities but does not form part of the core computer architecture. It is often, but not always, partially or completely dependent on the host.
There are three different types of peripherals:
(1) Input, used to interact with, or send data to the computer (mouse, keyboards, etc.).
(2) Output, which provides output to the user from the computer (monitors, printers, etc.).
(3) Storage, which stores data processed by the computer (hard drives, flash drives, etc.)" [Peripheral. Wikipedia]
The clip art example "Computer peripheral devices - Vector stencils library" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Computer and Networks solution from the Computer and Networks area of ConceptDraw Solution Park.

The circuit diagram example "Bipolar current mirror" was redesigned from the Wikipedia file: Current mirror.png.
[en.wikipedia.org/ wiki/ File:Current_ mirror.png]
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. [creativecommons.org/ licenses/ by-sa/ 3.0/ deed.en]
"A current mirror is a circuit designed to copy a current through one active device by controlling the current in another active device of a circuit, keeping the output current constant regardless of loading. The current being 'copied' can be, and sometimes is, a varying signal current. Conceptually, an ideal current mirror is simply an ideal inverting current amplifier that reverses the current direction as well or it is a current-controlled current source (CCCS). The current mirror is used to provide bias currents and active loads to circuits. ...
Basic BJT current mirror.
If a voltage is applied to the BJT base-emitter junction as an input quantity and the collector current is taken as an output quantity, the transistor will act as an exponential voltage-to-current converter. By applying a negative feedback (simply joining the base and collector) the transistor can be "reversed" and it will begin acting as the opposite logarithmic current-to-voltage converter; now it will adjust the "output" base-emitter voltage so as to pass the applied "input" collector current.
The simplest bipolar current mirror ... implements this idea. It consists of two cascaded transistor stages acting accordingly as a reversed and direct voltage-to-current converters." [Current mirror. Wikipedia]
The circuit diagram example "Bipolar current mirror" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Electrical Engineering solution from the Engineering area of ConceptDraw Solution Park.

"A logic gate is an idealized or physical device implementing a Boolean function, that is, it performs a logical operation on one or more logical inputs, and produces a single logical output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and unlimited fan-out, or it may refer to a non-ideal physical device...
Logic gates are primarily implemented using diodes or transistors acting as electronic switches, but can also be constructed using electromagnetic relays (relay logic), fluidic logic, pneumatic logic, optics, molecules, or even mechanical elements. With amplification, logic gates can be cascaded in the same way that Boolean functions can be composed, allowing the construction of a physical model of all of Boolean logic, and therefore, all of the algorithms and mathematics that can be described with Boolean logic.
Logic circuits include such devices as multiplexers, registers, arithmetic logic units (ALUs), and computer memory, all the way up through complete microprocessors, which may contain more than 100 million gates. In practice, the gates are made from field-effect transistors (FETs), particularly MOSFETs (metal–oxide–semiconductor field-effect transistors).
Compound logic gates AND-OR-Invert (AOI) and OR-AND-Invert (OAI) are often employed in circuit design because their construction using MOSFETs is simpler and more efficient than the sum of the individual gates.
In reversible logic, Toffoli gates are used." [Logic gate. Wikipedia]
The logic gate diagram template for the ConceptDraw PRO diagramming and vector drawing software is included in the Electrical Engineering solution from the Engineering area of ConceptDraw Solution Park.