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electrical_engineering_1:preparation_properties_proportions [2024/10/10 14:51] mexleadminelectrical_engineering_1:preparation_properties_proportions [2024/10/10 15:17] (aktuell) mexleadmin
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 <callout icon="fa fa-comment" color="blue" title="Definition of electrodes (according to DIN5489)"> <callout icon="fa fa-comment" color="blue" title="Definition of electrodes (according to DIN5489)">
 An electrode is a connection (or pin) of an electrical component. \\ An electrode is a connection (or pin) of an electrical component. \\
-As rule, the dimension of an electrode is characterized by the fact that a change of material takes place (e.g. metal->semiconductor, metal->liquid). \\+Looking at component, the electrode is characterized as the homogenous part of the componentwhere the charges come in / move out (usually made out of metal). \\
 The name of the electrode is given as follows:  The name of the electrode is given as follows: 
   * **A**node: Electrode at which the current enters the component.   * **A**node: Electrode at which the current enters the component.
   * Cathode: Electrode at which the current exits the component. (in German //**K**athode//)   * Cathode: Electrode at which the current exits the component. (in German //**K**athode//)
  
-As a mnemonic, you can remember the structure, shape, and electrodes of the diode (see <imgref BildNr8>).+As a mnemonic, you can remember the diode'structure, shape, and electrodes (see <imgref BildNr8>).
 </callout> </callout>
  
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 $R(\vartheta) = R_0 + c\cdot (\vartheta - \vartheta_0)$ $R(\vartheta) = R_0 + c\cdot (\vartheta - \vartheta_0)$
  
-  *  The constant is replaced by $c = R_0 \cdot \alpha$ +  * The constant is replaced by $c = R_0 \cdot \alpha$ 
-  *  $\alpha$ here is the linear temperature coefficient with unit: $ [\alpha] = {{1}\over{[\vartheta]}} = {{1}\over{{\rm K}}} $ +  * $\alpha$ here is the linear temperature coefficient with unit: $ [\alpha] = {{1}\over{[\vartheta]}} = {{1}\over{{\rm K}}} $ 
-  *  Besides the linear term, it is also possible to increase the accuracy of the calculation of $R(\vartheta)$ with higher exponents of the temperature influence. This approach will be discussed in more detail in the mathematics section below. +  * Besides the linear term, it is also possible to increase the accuracy of the calculation of $R(\vartheta)$ with higher exponents of the temperature influence. This approach will be discussed in more detail in the mathematics section below. 
-  *  These temperature coefficients are described with Greek letters: $\alpha$, $\beta$, $\gamma$, ...+  * These temperature coefficients are described with Greek letters: $\alpha$, $\beta$, $\gamma$, ..
 +  * Sometimes in the datasheets the value $\alpha$ is named as TCR ("Temperature Coefficient of Resistance"), for example {{electrical_engineering_1:tmp64-q1.pdf|here}}.
  
 <WRAP group><WRAP column> <WRAP group><WRAP column>
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 A series expansion can again be applied: $R(T) \sim {\rm e}^{{\rm A} + {{\rm B}\over{T}} + {{\rm C}\over{T^2}} + ...}$. A series expansion can again be applied: $R(T) \sim {\rm e}^{{\rm A} + {{\rm B}\over{T}} + {{\rm C}\over{T^2}} + ...}$.
  
-However, often only $B$ is given. \\ By taking the ratio of any temperature $T$ and $T_{25}=298.15~{\rm K}$ ($\hat{=} 25~°{\rm C}$) we get:+However, often only $B$ is given, for example {{electrical_engineering_1:datasheet_ntcgs103jx103dt8.pdf|here}}. \\ By taking the ratio of any temperature $T$ and $T_{25}=298.15~{\rm K}$ ($\hat{=} 25~°{\rm C}$) we get:
 ${{R(T)}\over{R_{25}}} = {{{\rm exp} \left({{\rm B}\over{T}}\right)} \over {{\rm exp} \left({{\rm B}\over{298.15 ~{\rm K}}}\right)}} $ with $R_{25}=R(T_{25})$ ${{R(T)}\over{R_{25}}} = {{{\rm exp} \left({{\rm B}\over{T}}\right)} \over {{\rm exp} \left({{\rm B}\over{298.15 ~{\rm K}}}\right)}} $ with $R_{25}=R(T_{25})$
  
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 <WRAP><callout> <WRAP><callout>
-=== Goal ===+=== Learning Objectives ===
 After this lesson you should be able to: After this lesson you should be able to:
   - Be able to calculate the electrical power and energy across a resistor.   - Be able to calculate the electrical power and energy across a resistor.