Electrical Symbols, Electrical Diagram Symbols

The vector stencils library "External digital devices" contains 15 clipart images of external digital devices and equipment for drawing computer network diagrams.
"Digital electronics, or digital (electronic) circuits, represent signals by discrete bands of analog levels, rather than by a continuous range. All levels within a band represent the same signal state. Relatively small changes to the analog signal levels due to manufacturing tolerance, signal attenuation or parasitic noise do not leave the discrete envelope, and as a result are ignored by signal state sensing circuitry. ...
Digital techniques are useful because it is easier to get an electronic device to switch into one of a number of known states than to accurately reproduce a continuous range of values. ...
An advantage of digital circuits when compared to analog circuits is that signals represented digitally can be transmitted without degradation due to noise. ...
In a digital system, a more precise representation of a signal can be obtained by using more binary digits to represent it. While this requires more digital circuits to process the signals, each digit is handled by the same kind of hardware. ...
Computer-controlled digital systems can be controlled by software, allowing new functions to be added without changing hardware. Often this can be done outside of the factory by updating the product's software. So, the product's design errors can be corrected after the product is in a customer's hands.
Information storage can be easier in digital systems than in analog ones. The noise-immunity of digital systems permits data to be stored and retrieved without degradation. ...
In a digital system, as long as the total noise is below a certain level, the information can be recovered perfectly." [Digital electronics. Wikipedia]
The clip art example "External digital 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.
www.conceptdraw.com/ solution-park/ computer-and-networks

"Satellite television is television programming delivered by the means of communications satellite and received by an outdoor antenna, usually a parabolic reflector generally referred to as a satellite dish, and as far as household usage is concerned, a satellite receiver either in the form of an external set-top box or a satellite tuner module built into a TV set. Satellite TV tuners are also available as a card or a USB peripheral to be attached to a personal computer. In many areas of the world satellite television provides a wide range of channels and services, often to areas that are not serviced by terrestrial or cable providers.
Direct-broadcast satellite television comes to the general public in two distinct flavors - analog and digital. This necessitates either having an analog satellite receiver or a digital satellite receiver. Analog satellite television is being replaced by digital satellite television and the latter is becoming available in a better quality known as high-definition television." [Satellite television. Wikipedia]
"Mobile television is television watched on a small handheld or mobile device. It includes pay TV service delivered via mobile phone networks or received free-to-air via terrestrial television stations. Regular broadcast standards or special mobile TV transmission formats can be used. Additional features include downloading TV programs and podcasts from the internet and the ability to store programming for later viewing. ...
Mobile TV is among the features provided by many 3G phones." [Mobile television. Wikipedia]
"MobiTV, Inc. ... is a provider of end-to-end mobile media solutions. In 2011, the cloud-based MobiTV converged media platform delivered 1.6 billion minutes of live TV, video-on-demand and downloaded content for offline viewing to all tier-one wireless carriers and major mobile operating systems in the United States. ...
MobiTV furnishes programming from more than 40 television channels, offering live news and sports and a variety of full-episode on-demand shows for streaming or download on mobile devices, tablets, personal computers and other Internet-enabled consumer electronics.
MobiTV-powered TV services, which carry the operator’s brand, are accessible on hundreds of devices across multiple wireless carrier partners. ...
MobiTV’s converged media platform is an end-to-end managed service comprising components that work together to securely manage, deliver and play back video across devices both inside and outside the home." [MobiTV. Wikipedia]
This mobile satellite TV network diagram example was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Telecommunication Network Diagrams solution from the Computer and Networks area of ConceptDraw Solution Park.

The vector stencils library "Analog and digital logic" contains 40 element symbols of logic (threshold) gates, bistable current switches, current controllers, regulators, electrical generators, and amplifiers.
Use it for drawing the digital and analog functions in electronic circuit diagrams and electrical schematics.
"Analogue electronics (or analog in American English) are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two different levels. The term "analogue" describes the proportional relationship between a signal and a voltage or current that represents the signal." [Analogue electronics. Wikipedia]
"Digital electronics, or digital (electronic) circuits, represent signals by discrete bands of analog levels, rather than by a continuous range. All levels within a band represent the same signal state. Relatively small changes to the analog signal levels due to manufacturing tolerance, signal attenuation or parasitic noise do not leave the discrete envelope, and as a result are ignored by signal state sensing circuitry.
In most cases the number of these states is two, and they are represented by two voltage bands: one near a reference value (typically termed as "ground" or zero volts) and a value near the supply voltage, corresponding to the "false" ("0") and "true" ("1") values of the Boolean domain respectively.
Digital techniques are useful because it is easier to get an electronic device to switch into one of a number of known states than to accurately reproduce a continuous range of values.
Digital electronic circuits are usually made from large assemblies of logic gates, simple electronic representations of Boolean logic functions." [Digital electronics. Wikipedia]
The example "Design elements - Analog and digital logic" 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.