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Sep 30, 2022 · A short circuit is when there is a low resistance connection between two conductors that are supplying electrical power to a circuit. This would generate an excess of voltage streaming and cause excessive flow of current in the power source. The electricity will flow through a ‘short’ route and cause a short circuit.
- Overview
- Circuit
- Schematic
- Schematic equivalence
- A schematic puzzle
- Concept check: Equivalence
- Drawing a good schematic
Glossary of terms we need to talk about circuits and schematics. Nodes, branches, loops and meshes, reference node and ground, and schematic "equivalence." Written by Willy McAllister.
We are developing methods for analyzing a circuit. So far we've defined the most common components (resistor, capacitor, and inductor) and sources (voltage and current). Now we need a crisp vocabulary to talk about circuits. This article is a glossary of terms and concepts we use in circuit analysis and design.
•(Choice A)
3 nodes
•(Choice B)
4 nodes
Circuit comes from the word circle. A circuit is a collection of real components, power sources, and signal sources, all connected so current can flow in a complete circle.
Closed circuit – A circuit is closed if the circle is complete, if all currents have a path back to where they came from.
Open circuit – A circuit is open if the circle is not complete, if there is a gap or opening in the path.
Short circuit – A short happens when a path of low resistance is connected (usually by mistake) to a component. The resistor shown below is the intended path for current, and the curved wire going around it is the short. Current is diverted away from its intended path, sometimes with damaging results. The wire shorts out the resistor by providing a low-resistance path for current (probably not what the designer intended).
A schematic is a drawing of a circuit. A schematic represents circuit elements with symbols and connections as lines.
Elements – The term elements means "components and sources."
Symbols – Elements are represented in schematics by symbols. Symbols for common 2-terminal elements are shown here,
Lines – Connections between elements are drawn as lines, which we often think of as "wires". On a schematic, these lines represent perfect conductors with zero resistance. Every component or source terminal touched by a line is at the same voltage.
Dots – Connections between lines can be indicated by dots. Dots are an unambiguous indication that lines are connected. If the connection is obvious, you don't have to use a dot.
Reference designator – When you place a component in a schematic you often give it a unique name, known as a reference designator. Examples of reference designators are R1 , C6 , and VBAT . The 1 in R1 is part of the name, and does not indicate the resistance value. Reference designators are by definition unique for each schematic. They let you identify components by name even if some of them have the same value. It is okay to use reference designators in equations. R1 can be assigned a resistance value, R1=4.7kΩ , and it can be used as a variable in expressions, as in R2⋅C6=4.7kΩ⋅2μF .
We need to take a second to talk about the idea of schematic equivalence. This is important because a circuit can be represented by schematics drawn in different ways.
The following two schematics are drawn differently. The schematic on the left shows a voltage source and three resistors in numerical order. In the schematic the right, resistor R3 appears to the left of the voltage source.
Do both of these schematics properly represent the intended circuit? Or said another way,
Are these two schematics equivalent?
We say a real circuit and a schematic (or two schematics), are equivalent if they have the same nodes and branches.
To be equivalent, two schematics must:
I'm going to point out something that may seem baffling, (but only for a moment). As we just established, the following two schematics are equivalent. But, not everything is exactly the same. The individual point-to-point connections of the lines between elements are not the same.
Look at the blue arrow in the left schematic. That wire carries the current flowing towards R2 and R3 .
Can you find the equivalent wire in the schematic on the right?
(Find a wire carrying the current going to R2 and R3 .)
[Where is that wire?]
What is going on? It is a trick question, to highlight something about the nature of schematics.
Here is a brainteaser to help you check your understanding of schematic equivalence.
Which of these schematics represent the same circuit (are equivalent)?
Assume all resistors have the same value.
Take your time, this isn't simple.
Hint: There are three answers.
[show a hint]
A good schematic serves a number of noble purposes. A good schematic
•captures the design of a circuit in an unambiguous way.
•allows you to share your design with other people.
•helps you remember how your circuit works, even a month from now.
Both you and your colleagues will appreciate these drawing habits for creating good schematics,
•Place inputs on the left, and outputs on the right.
Mar 1, 2021 · An open circuit is defined as an electric circuit in which current does not flow. Current can only flow in a circuit if it finds a continuous path—known as a “closed circuit”. If there’s a break anywhere in the circuit, you have an open circuit, and current can not flow. In an open circuit, the two terminals are disconnected.
People also ask
How does an open circuit differ from a short circuit?
What is a short circuit in electrical?
What is the difference between a close circuit and a short circuit?
What causes a short circuit?
phys. Disruption in an electric circuit, caused by the flow of charge along a low-resistance path between two points that should not be directly connected, thus deflecting the current from its proper path; an effective “shortening of the circuit.” ཕན་ཚུན་ཐད་ཀར་ཐུག་མི་རུང་བའི་སྣེ་གཉིས་དབར་གྱི ...
Nov 21, 2023 · An open circuit is one that contain a break in the electrical connections. This break can be intentional in the case of using a switch, or unintentional in the case of a broken wire. A closed ...
- How do you make a complete circuit?To make a simple DC complete circuit you will need a battery, wires and a load (object being powered). Wires must be connected to the poles of the...
- What is needed for a complete circuit?In order to have a complete circuit there must be at least a power source, wires and a load. The wires are connected to each pole of the power sour...
- What is an example of a open circuit?An open circuit is one in which the electrical connections are broken or disconnected. This can be intentional by using a switch or unintentional i...
- What is an example of a complete circuit?A complete circuit is one in which the electrical connections are all connected. An example would be in a home when a light switch is turned on. El...
A short circuit is simply a low resistance connection between the two conductors supplying electrical power to any circuit. This results in excessive current flow in the power source through the 'short,' and may even cause the power source to be destroyed.
May 23, 2017 · The most common definition of a short circuit is any time the equations for the model of your circuit suggest that a single wire must have two different voltages. As you know an ideal wire has the same potential at all points along the wire. If your equations suggest that a wire must be held at 2 different voltages at once, you have a short ...
