diff --git a/uni/mmme/2051_electromechanical_devices/exercise_sheets/Exercise Sheet 11 - Transformers.pdf b/uni/mmme/2051_electromechanical_devices/exercise_sheets/Exercise Sheet 11 - Transformers.pdf new file mode 100644 index 0000000..16d2d56 Binary files /dev/null and b/uni/mmme/2051_electromechanical_devices/exercise_sheets/Exercise Sheet 11 - Transformers.pdf differ diff --git a/uni/mmme/2051_electromechanical_devices/images/how.png b/uni/mmme/2051_electromechanical_devices/images/how.png new file mode 100644 index 0000000..66d3872 Binary files /dev/null and b/uni/mmme/2051_electromechanical_devices/images/how.png differ diff --git a/uni/mmme/2051_electromechanical_devices/images/vimscrot-2023-03-23T11:15:40,310863581+00:00.png b/uni/mmme/2051_electromechanical_devices/images/vimscrot-2023-03-23T11:15:40,310863581+00:00.png new file mode 100644 index 0000000..677d564 Binary files /dev/null and b/uni/mmme/2051_electromechanical_devices/images/vimscrot-2023-03-23T11:15:40,310863581+00:00.png differ diff --git a/uni/mmme/2051_electromechanical_devices/images/vimscrot-2023-03-23T11:17:40,931099514+00:00.png b/uni/mmme/2051_electromechanical_devices/images/vimscrot-2023-03-23T11:17:40,931099514+00:00.png new file mode 100644 index 0000000..6a2944b Binary files /dev/null and b/uni/mmme/2051_electromechanical_devices/images/vimscrot-2023-03-23T11:17:40,931099514+00:00.png differ diff --git a/uni/mmme/2051_electromechanical_devices/lecture_slides/MMME2051EMD_Lecture8.pdf b/uni/mmme/2051_electromechanical_devices/lecture_slides/MMME2051EMD_Lecture8.pdf new file mode 100644 index 0000000..ce854f6 Binary files /dev/null and b/uni/mmme/2051_electromechanical_devices/lecture_slides/MMME2051EMD_Lecture8.pdf differ diff --git a/uni/mmme/2051_electromechanical_devices/transformers.md b/uni/mmme/2051_electromechanical_devices/transformers.md new file mode 100755 index 0000000..bf933dd --- /dev/null +++ b/uni/mmme/2051_electromechanical_devices/transformers.md @@ -0,0 +1,37 @@ +--- +author: Akbar Rahman +date: \today +title: MMME2051 // Transformers +tags: [ transformers, alternating_current, ac ] +uuid: 486f441f-14ec-41e5-94f9-06f25c534086 +lecture_slides: [ ./lecture_slides/MMME2051EMD_Lecture8.pdf ] +exercise_sheets: [ ./exercise_sheets/Exercise Sheet 11 - Transformers.pdf ] +--- + +Transformers are used to convert between AC voltages. + +Transmission is always done at very high voltage to reduce copper losses (heat loss, $E = i^2R$). + +![](./images/how.png) + +A current carrying coil induces a magnet inside the core. +Another coil is wrapped around the core. +This coil has a current induced in it by induced magnetic field. + +![](./images/vimscrot-2023-03-23T11:15:40,310863581+00:00.png) + +$$\frac{i_s}{i_p} = \frac{v_p}{v_s} = \frac{n_p}{n_s} = \text{turns ratio}$$ + +**Note that the current fraction is s over p, not p over s like the others.** +Derivation in lecture slides (pp. 12-15). + +Transformers are usually described as having a ratio $p:s$, where $p$ is the number of primary coils +and $s$ the number of secondary coils. + +![Symbol of an "Isolaton Tranformer". The dot indicates polarity.](./images/vimscrot-2023-03-23T11:17:40,931099514+00:00.png) + +## Referred Impedance + +$$\frac{Z_P}{Z_S} = \left(\frac{n_p}{n_s}\right)^2$$ + +Derivation in in lecture slides (pp. 19-21).