65 lines
2.2 KiB
Markdown
Executable File
65 lines
2.2 KiB
Markdown
Executable File
---
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author: Akbar Rahman
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date: \today
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title: MMME2051 // Diodes and Rectifiers
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tags: [ diodes, rectifier ]
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uuid: 21cf8e5b-d808-412c-bb71-d298cdb02b4f
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lecture_slides: [ ./lecture_slides/MMME2051EMD_Lecture8.pdf ]
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lecture_notes: []
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exercise_sheets: []
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---
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Diodes are like one way valves for electricity --- they allow current to flow in the forward
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direction but not in the reverse.
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Pure semiconductors are often intentionally doped by specific impurity to alter
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its electrical properties.
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The most basic thing you can produce with this is the PN junction (or, a diode):
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- $I_\text{leak}$ is the current that is able to flow in the reverse direction.
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It is a very small amount.
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- Forward voltage, $V_f$, is the voltage required to move current forward.
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- Forward bias impedance, $Z_f$, shows that the diode has a low resistance until a certain point.
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- At a certain point a diode will fail to block the reverse voltage (DC blocking voltage)
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# Rectification
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How the rectifiers work are stepped through in lecture slides (pp. 32-44)
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The most basic rectification is very wasteful:
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This produces a waveform like this:
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This is a step in the right direction but it is still very wasteful and not a smooth
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voltage at all.
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A H-Bridge (full bridge) rectifier allows the negative cycle to be harnessed as well:
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This produces a voltage like:
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Capacitors can be added to smooth out the voltage:
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This produces a voltage like:
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