47 lines
1.3 KiB
Markdown
47 lines
1.3 KiB
Markdown
<img src="https://i.imgur.com/ZPadVTR.jpg" /img>
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E : the voltage corresponding to Ua - Ub = Uab
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V = Ub - Uc
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The current correponding to the flow of electrical electrons from A to C in A
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**Dipoles :** component between two points of the diagram
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**Ohm's law**: $V=R \times{I}$
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<img src="https://i.imgur.com/a9skJL3.png" /i>
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## Association of resistors
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### resistors in serie
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$R_{1}$ and $R_{4}$ get the same flow (current). Replace R1 and R4 by $R_{s} = R_{1}+R_{4}$
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### Resistors in parallel
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$R_{2}$ and $R_{3}$ see the same voltage:
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$U_{2} = U_{c}-U{b}$, $U_{3} = U_{d}-U{b}$ and $U_{d} = U_{c}$
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$R_{2}$ and $R_{3}$ are replaced by $R_{P}$ :
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$R_{P}=\frac{R_{3}\times{R_{2}}}{{R_{3}+R_{2}}}$
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## Definitions
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- A branch is a link between 2 points in the diagram
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- A node is a point in the diagram linked to at lease 3 branches
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- A loop is a draw from a point in the diagram to itself.
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> ⚠️ In a loop we don't use the same path twice or more
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Exemple:
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```mermaid
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flowchart LR
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C --> D --> B --> C
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```
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```mermaid
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flowchart LR
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A --> C --> B --> A
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```
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## Different laws
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### Kirchhoff's laws
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- The addition of voltages in a loop = 0
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exemple : $V_{AC} + V_{CB} + V_{BA} = 0$
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- The algebraic sum of currents into a node = 0
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Exemple : $\text{Node(C)} = I - I_{2} - I_{3} = 0$
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### Kirchhoff's laws & Ohm's law
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We can't calculate $I$, $I_{2}$ and $I_{3}$
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