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Many problems are naturally formulated in terms of objects and connections between them. Finding the best route through the city can be solved by analyzing the graphical representation of the. Electric circuit is another important concern. Graphs help to find out the connection of all elements in the circuit.

For now, let us focus on schematic approach. Let us analyze circuits at all, as well as their components, interconnections, work, cooperation, etc. Circuit is a complex path for some matter traveling through it. (electrons in electric circuits, liquid/gas in hydro/pneumatic circuits) In general, circuit components can be characterized as elements, leads, input, output. Any circuit path can be opened or closed at any point, either manually or automatically, discretely (on/off) or continuously (rheostat, flow control valve) All circuits have places with different levels of the speed of matter, (i.e. different voltage, different air pressure) and with a different volume of matter (different Amperage … different volume of air) circuits have places where the matter is stored

Contents 1 Physical circuits 1.1 Learning 1.2 Properties 1.2.1 Linear networks 1.2.2 First order networks 1.2.3 With electronic switches … amplifiers 1.2.3.1 Comparisons on Different levels of complexity 1.3 Engineering and construction 1.4 Simplifying and extending the circuits 1.5 Maintaining 1.6 Mathematical calculation algorithms 2 Virtual circuits 2.1 Chapter 1. 2.1.1 Node (Vertex) 2.1.2 Branch (Edge) 2.1.3 Path (from one node to another) 2.1.4 Tree 2.1.5 Directed graphs 2.1.6 Cut set 2.1.7 Leads 2.1.8 Pistons 2.1.9 Valves 2.1.10 Air tanks 2.1.11 Actuators 2.1.12 Pulse valve 2.2 Bibliography

[edit] Physical circuits

can be seen as some unite physical system, since they exist physically . What can be done with circuits, and how…

[edit] Learning

understanding, applying common sense & principles. (Similar and different components)

[edit] Properties

Pneumatic analogies to Voltage Current Resistance, Capacitance, Inductance etc.

[edit] Linear networks

Pneumatic circuits from . Electric circuits from college courses. Steady state, transients. Diodes. Pulse valves vs. Zener diode circuits.

[edit] First order networks

[edit] With electronic switches … amplifiers

Chemical process diagrams and descriptions, vs. Telephone / Computer networks.

[edit] Comparisons on Different levels of complexity

[edit] Engineering and construction

==Troubleshooting==)

[edit] Simplifying and extending the circuits

[edit] Maintaining

[edit] Mathematical calculation algorithms

Newtwork from Algorythm (Robert Sedgewick book pages 485-493) with the electric circuit analysis algorithms.

[edit] Virtual circuits

cannot be seen as unite physical system. They can be realized by hard-to-visualize means.

     Working computer software is a perfect example. Software is a script for a computer hardware which will direct it to live up its components, logic gates, memory, etc so … that computer will do what is stated. 

The chain of work done according to the plan is also very hard to visualize. Rarely the entire chain exist physically, however its actions can be drawn as a flow chart and explained as a circuit.

[edit] Chapter 1.

General topological approach: “…Network topology focuses on the constraint imposed by circuit interconnections, and enables us to arrive at an efficient means of writing the minimum number of independent equations that describe the circuit. The topological character of a circuit is completely specified by graph. Topology refers to the science of space, where the figures are visualized to become elastic. They can be stretched, twisted, squeezed, pulled, and bent. Two figures are topologically equivalent if and only if one figure can be made to coincide another with an elastic deformation. Two networks are different only if the elements that make the branches are different. So, for any graph, or a topologically scheme model let us define the following terms.

[edit] Node (Vertex)

can represent both an object and the place where Branches/edges are connected depending on nature of a circuit) in electric and pneumatic circuits they represent the point (actually areas) where the components are interconnected. Components are rather branches/edges.

[edit] Branch (Edge)

represents a connection between 2 vertices/nodes. In electric/pneumatic circuits they represent the components (or parts of components them) In weighted graphs the “weight” of each edge represents the resistance, capacitance, inductance, etc as of electronic circuits. In pneumatic circuits the weight can represent the air permittivity, capacitance, etc.

[edit] Path (from one node to another)

in a graph is a list of edges, in which successive vertices are connectecd. A part of circuit to be analyzed.

• Loop
• Mesh
• Planar
• Nonplanar

[edit] Tree

is a set of connecting branches that connects every node to every other node without forming closed paths, or loops. Three+ terminal component, such as transistor can treated as a tree.

[edit] Directed graphs

feature some of their edjes leading only in one direction.

[edit] Cut set

is a minimal set of branches which divides the graphs into two groups of nodes.

Analyze mesh and node analysis in terms of CS202 book, and do the same with pneumatic analysis methods. Compare and contrast.

Based on these principles, let us comparing pneumatic circuits with electric ones:

         An electrical circuit is a network that has a closed loop, giving a return path for the current. A network is a connection of two or more components, and may not necessarily be a circuit.

[edit] Leads

• in electricity electric wires are used for carrying electrons. They are made of conducting material. They are thin to form a direct path from point A to point B.
• In pneumatics, the houses or tubes are used for carrying the flow of air. They have and open air inside to make a space inside which an air can move freely. They are covered by a plastic layer to prevent air of spreading out.

[edit] Pistons

They can be compared with any simple executive mechanism like a light bulb, speaker, electric heater solenoid, etc.

• The electrons come inside a light bulb, they heat up the piece of metal inside it, so it radiates the light, heat. Speaker and solenoid – do some action upon electricity (to be simple). When the electrons leave it it stop the action.
• The air comes inside the piston cylinder, and provides a needed pressure to hold it. Upon release of that pressure, the piston turns back.

[edit] Valves

imply a straightforward comparison with electric switches.

• Electric switch can open or close the circuit. By opening the circuit it makes a straight pass for electrons from the current/voltage source, and ground.
• In pneumatics, it does absolutely the same job with the air flow.

Both in Pneumatics and Electricity switches can be manipulated mechanically, automatically, and by other means.

[edit] Air tanks

Their electric equivalent is a capacitor, or a battery. (Depending on size)

• Electric capacitors accumulate the voltage applied to their plates, and then during the discharge this voltage can be used for powering the components of the circuit.
• Air tanks are used for accumulating the air applied to them. During discharge this air can be autonomously for a circuit.

[edit] Actuators

Are (simply speaking) automatically operated switches (both electrically and mechanically). They can be compared with electromagnetic relays, and other semiconductor switching devices as Thyristors, Transistors, SRCs, etc.

• In an electromagnetic relay, current enters the electromagnetic coil, the coil is getting magnetized and attracts a metal parts of the electric switch, which closes the contacts.
• In a pneumatic actuator, the air pressurizes the chamber, pushes the piston inside, and piston operates the switch

[edit] Pulse valve

is a very complex component to find an electric equivalent for it. Give a couple of examples where EM320 pneumatic circuits are compared with electric ones.

[edit] Bibliography

ALgorythms in C++ by Robert Sedgewick Electric Circuits (old book) Chapter 5 Electromechanical Devices course manual, by Peter B. from New York City COllege of Technology